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Litter-free manure

Litter-free manure is a polydisperse suspension of solid and liquid animal excreta with fluid properties, sometimes containing feed losses. Fluidity of manure simplifies its removal from livestock buildings and creates conditions for mechanization of works.

Litter-free manure is a polydisperse suspension of solid and liquid animal excreta with fluid properties, sometimes containing feed losses. Fluidity of manure simplifies its removal from livestock buildings and creates conditions for mechanization of works.

Liquid manure is produced at livestock complexes. Traditional technology of animal housing on straw litter requires labor costs to remove straw from fields, transportation, removal from the premises as part of the manure, removal to the field and spreading. The high costs of using litter have begun to hold back productivity growth on large farms. Therefore, the practice of designing and building large livestock complexes and industrial farms introduces litter-free cattle housing technologies.

Depending on water content, litter-free manure is divided into:

  • semi-liquid – up to 90% of water;
  • liquid – 90-93% of water;
  • slurry – more than 93% water.

An increase in moisture content of manure is accompanied by an increase in its volume. Thus, an increase in moisture content from 90 to 92% leads to an increase in volume by 25%, with an increase to 94% – by 65-70%, with an increase to 96% – 2.5 times. Increase of moisture content leads to serious economic and logistical consequences of accumulation, storage, transportation and application of these volumes.

The yield of liquid manure from one head of cattle is 55 kg per day, pigs – 50 kg. In terms of nutrient content pig manure is comparable with cattle manure. In liquid manure, 50-70% of nitrogen is in soluble form, which is assimilated by plants in the first year. The rest is organically bound protein nitrogen, which later transforms into plant-available form as it mineralizes. The mainly organically bound phosphorus contained in liquid manure is better used by plants than the phosphorus of mineral fertilizers. Potassium in liquid manure is represented by the soluble form.

Nitrogen and organic matter losses during liquid manure storage are several times less than during dense litter storage. However, the use of liquid manure requires changes in transportation, storage and application technology.

Depending on soil-climatic and organizational and economic conditions liquid manure is stored for 2-6 months. During storage it stratifies into solid and liquid parts with different fertilizer properties. For uniform use of nutrients in the fertilized area and for more reliable operation of the spreader tank pumps and sprinkler systems, the stratification is prevented. To do this, it is mixed in the storage with special devices, achieving a homogeneous condition. Sometimes fractions are used separately: liquid – for irrigation through sprinkler system, solid – for composting or spreading with manure spreader.

Litter-free manure produced by feeding concentrated feed to animals has a higher content of nutrients. The table shows the average chemical composition of undiluted litterless manure. When concentrates are reduced in diets, nitrogen and phosphorus content decreases, potassium content increases.

Table. Chemical composition of litter-free manure and litter, %[1]Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al; ed. by V.G. Mineev. - M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, … Continue reading

Cattle manure
Pig manure, 108,000 head complex
Sheep manure
Chicken manure
10,000 steers complex
2000 cows complex
Dry matter
Total nitrogen
Phosphorus (P2O5)
Potassium (K2O)

The content of ammonia nitrogen in litter-free manure is 50-70% of the total. Therefore, the first fertilized crop is provided with nitrogen 2-3 times better than the equivalent total nitrogen dose of bedding manure. Pig manure sometimes needs to be supplemented with potash fertilizer if the plants need it or if the soil is poorly supplied with potassium.

Phosphorus and potassium of litter-free manure in equivalent doses have the same effect on plants as litter manure.

The content of dry matter and nutrients in the litter-free manure decreases in proportion to increasing volumes when diluted with water. Nitrogen losses during storage for 3-4 months, according to the All-Russian Institute of Fertilizers and Agrochemistry, is 10-12%.

The organic matter constitutes 70-80% of dry weight of litter-free manure, the ratio C: N is less than in the litter, so it is more rapidly mineralized and better provides the first fertilized crop with nitrogen and other elements. For this reason, litter-free manure has a short aftereffect and at equivalent organic matter content by 40% weaker than the litter manure participates in the new humus formation.

Litter-free manure is a link in nutrient cycles in agriculture, because up to 50-80% of nitrogen, 60-80% of phosphorus, 80-95% of potassium, up to 90% of calcium, 60% of organic matter pass into the manure. The litter-free manure also contains trace elements: 1 ton of cattle manure with a moisture content of 92% contains 2.8 g of copper, 22 g – manganese, 12 g – zinc, 2.4 g – boron, 1 ton of pig manure with a humidity of 95% – 2.9 g copper, 12 g – manganese, 32 g – zinc, 0.11 g – molybdenum.

Litter-free manure is a source of organic matter for reproduction of soil humus. On average, about 5 kg of dry matter comes from one head of cattle per day. Fecal organic matter includes cellulose, hemicellulose, lignin, pentosans and other substances. The C:N ratio in litter-free manure varies from 5:1 to 10:1.

Litter-free manure application technologies

Technological schemes of litter-free manure use:

  • On-farm manure storage tank – cistern – field manure storage tank – spreader tank – field.
  • On-farm manure storage – pipeline – field manure storage (hydrant) – spreader tank – field.
  • Manure storage – pipeline network – sprinkler system – cistern spreader – field.

The first scheme is used when there is no pipeline for pumping from the on-farm storage to the field. In this case, it is unloaded into spreader tanks, hauled to the field and filled into field manure storage tanks for storage before spreading. During application, manure from on-farm and field storages is loaded into spreader tanks, transported to the field, spread over the surface, and then, as soon as possible, incorporated into the soil.

The second scheme is more efficient than the first in the absence of a pipeline network and sprinkler systems. Transportation of liquid manure from on-farm storage to field storages via pipes with subsequent application by spreader tanks allows to reduce transportation costs and increase labor productivity. Dilution with water is not provided for in the first and second schemes.

The third scheme is used in the presence of a pipeline network and sprinkler installations. During vegetation period when it is necessary to water plants, the manure after storage in undiluted form is diluted with water in ratio of 1:8-10. During non-growing period it is diluted in the ratio of 1:1-3. Operation according to this scheme does not exclude the use of spreader tanks for application of undiluted manure and in the absence of irrigation system.

For large livestock complexes of industrial type it is most appropriate to use the 3rd technological scheme. In this case it is possible to use both on rainfed and irrigated areas. On irrigated areas they are usually used at application of litter-free manure under plowing or pre-sowing tillage.

Dilution of manure with water is carried out in the pipeline transport stream with installed manure and water flow sensors. The degree of manure dilution can be set automatically.

When using manure as fertilizer according to the 2nd and 3rd technological schemes, construction of field manure storage tanks is often inexpedient. Instead of them, small tanks of field filling stations or hydrants for filling of spreader tanks or feeding to sprinkler systems are installed.

The total volume of field and on-farm manure storages should provide storage of manure amounts which accumulate during the time when it cannot be removed and applied to the soil, for example, during autumn and spring roadlessness, absence of free fields. Storage capacity is designed according to this period, livestock and manure yield, usually at least 2 months in advance. 25-40% of the total capacity should be for on-farm manure storage and 60-75% for field manure storage, placed in the center of fertilized areas if possible.

Depending on soil and climatic and organizational and economic conditions, storage duration ranges from 2-3 months in southern areas to 5-6 months in northern areas. During storage, compliance with veterinary and sanitary regulations, environmental protection requirements and economic feasibility should be ensured. The latter is facilitated by the reduction of water consumption for manure removal and cleaning, as well as the period of its storage.

If there are pipelines, storage of the entire mass of manure is possible in on-farm storage facilities. In this case they are connected by pipelines to field filling stations or hydrants. Access roads to storages must have a hard surface designed for movement of vehicles and tractors weighing 3-5 tons. Drainage gutters should be provided around the manure storehouse.

Manure storages should be fenced and planted with trees, and closed tanks should be ventilated, since the storage of liquid manure accumulates significant amounts of methane, hydrogen sulfide, carbon dioxide, and ammonia. It is forbidden to use open fire for lighting to avoid explosion.

Liquid manure produced at large livestock industrial complexes is decontaminated before use. If there are no acute contagious diseases on small farms, liquid manure is used without disinfection. Only sprinkling or feeding such manure on vegetable, fruit and other crops consumed raw without pre-treatment is not allowed. It is not recommended to apply liquid manure by sprinkling when the wind is strong in the direction of settlements.

Accumulation and storage of litter-free manure

The amount of litter-free manure is determined by different methods: for a stable herd structure, by standards of excrement yield of different animal species:

Calculation of litter-free manure yield
Calculation of litter-free manure yield

where (feces + urine) – amount of excrements per day from one head of cattle, kg; D – duration of stabling period, days; N – number of livestock; 1000 – conversion in m3; (feces + urine + water) – daily amount of excrements plus amount of water according to given technology, kg.

Another method of calculation is based on the results of analyses and data of balance experiments:

Calculation of litter-free manure yield

where Y – annual excrement yield, t; R – annual dry matter consumption of rations, t; L – annual dry matter losses during feeding, t; K – feed digestibility coefficient, % (for cattle 60%, pigs 70%); 10 – dry matter content in excrements, %.

Used technologies, facilities and technical means of cleaning, disinfection, deodorization, storage, transportation and application of litter-free manure in different soil and climatic conditions affect the composition, properties and fertilizer value of manure, manure effluent and products of their treatment. Factors affecting the fertilizer value of litter-free manure include: disposal methods, i.e. dilution with water, separation into fractions, anaerobic and thermal treatment.

When storing litter-free manure with a moisture content above 90%, it stratifies into three layers:

  • upper one, floating, contains feed residues and some solid excrement, with a moisture content of 78-84%, and contains almost no ammonia nitrogen;
  • lower layer – settled solid particles of manure, sand, silt with moisture content of 84-88% and small amount of ammonia nitrogen;
  • middle – clarified liquid with 88-94% of water, rich in ammonia nitrogen.

Homogenization of litter-free manure in storages with special devices is necessary for quality loading, transportation and application.

In preparation for use for fertilizer irrigation, manure is separated into solid and liquid fractions by natural sedimentation or, less frequently, by filtration, straining, decantation, pressing and separation, even more rarely by electrical and chemical coagulation. With natural sedimentation, the more nutrients get into the liquid fraction, the greater the dilution of manure (effluent) with water. When the moisture content of runoff is 98%, according to the All-Russian Institute of Fertilizers and Agrochemistry, the settled liquid fraction contains 71% of total and 78% of ammonia nitrogen, 37% of phosphorus and 82% of potassium.

Thermal treatment is a method of disinfection and dehelminthization of litter-free manure based on coagulation of proteins, including nonsporous microorganisms, eggs and helminth germs at temperatures above 56 ° C. Heating for a day at this temperature causes practically no loss of nitrogen, while drying to constant weight at 105 ° C leads to losses of 50-75% of total and 95-99% of ammonia nitrogen.

Anaerobic treatment is a way to disinfect, de-worm and deodorize manure using methane bacteria at 30-32 °C (mesophilic mode) or 56-58 °C (thermophilic mode). Thermophilic mode is preferable because within three days it allows to destroy helminth eggs, flies and pathogens of infectious diseases. Fermented manure does not differ from the original manure in terms of its fertilizing value, and the methane produced is used as biofuel.

Treatment with formalin at the rate of 1-5 liters per 1 ton of manure disinfects, slows down microbiological processes, decreases mineralization rate, eliminates odor, reduces nitrogen losses (due to formation of urotropine – slow acting nitrogen fertilizer – from interaction of ammonia and formalin). Application of such manure inhibits nitrification of nitrogen in soil for three months and reduces possible nitrogen losses.


Litter-free manure application

The use of litter-free manure depends on the composition and transport possibilities. That said:

  • manure should not be stored for long periods of time, as this leads to overfilling of storage facilities, environmental contamination, and the spread of infections and infestations;
  • application rates are determined on the basis of nutrient content to obtain the planned yields while regulating the balance of soil organic matter;
  • apply to fields where rapid incorporation into the soil is possible;
  • in autumn on low-capacity soils (sandy, sandy loam, light loam) manure is brought with straw (peat) or under winter (stand-up, intermediate) crops to prevent washout of nutrients;
  • application in winter on areas flooded in spring and on slopes is avoided;
  • when the arable horizon is deepened, manure is applied to the turned-out layer for plowing and discing;
  • in arid regions, manure is applied under mouldboard tillage alternating with non-moldboard;
  • the minimum application rates for continuous application of homogenized manure for row crops is 25 tons/ha, for cereals – 15 tons/ha;
  • smaller application rates are not effective enough, it is difficult to apply them evenly.

At the expense of pre-sowing application, depending on the type and productivity of plants, it is advisable to satisfy up to 50-80% of the crops’ need for nitrogen.

For fertilizing irrigation of vegetating plants manure before application with water is diluted 6-8 times, during non-vegetative period – 2-4 times. Drainage water from areas irrigated with diluted manure is directed for repeated irrigation to prevent pollution of water sources.

To prevent pollution of surface and ground water combine the introduction of manure with chopped straw, as well as with the help of intermediate and stand-up crops – keep them permanently occupied by plants, intercepting the mobile forms of the nutrient elements of manure and soil.

Rates of application of litter-free manure are determined depending on the needs of crops in nitrogen, taking into account its content in the fertilizer. Doses of nitrogen for different crops depending on the productivity range from 120 to 360 kg / ha. Litter-free manure is used before sowing (in autumn, winter or spring) and in top dressing for row crops, fodder crops and other crops, except for vegetable crops.

Pre-sowing application of litter-free manure to soil shall be carried out by irrigation and drainage lines and installations or by tank-dispersersers such as РЖТ-8, РЖТ-16, with subsequent embedding by plough or heavy disk harrows.

On pastures, according to sanitary requirements liquid manure shall be applied not later than 30 days before grazing, and better in late autumn. When meadows are improved superficially, the litter-free manure is applied before tillage with a heavy disc harrow or a milling machine. For hygienic reasons it is not allowed to apply litter-free manure to vegetable crops.

Plant uptake of nitrogen, phosphorus and potassium in the year of application of litter-free manure increases 2-fold when embedded in the soil compared to spreading on the surface without embedding, and is almost the same as half-decomposed litter manure of dense storage method.

Rates and timing of litter-free manure application

Rates of application of litter-free manure are set on the basis of the crop’s need for nitrogen and its content in the manure, as nitrogen has the greatest impact on the yield. Under irrigation conditions the dosage may be higher. Application rates should be calculated taking into account soil type, granulometric composition, timing of application, as well as precursors, transportation distance and crop response to high doses of fertilizers.

Table. Approximate rates of application, terms of application and methods of embedding litter-free cattle manure with nitrogen content of 0.4%[2]Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. - M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, 2017. - 854 p.

Agricultural crop
Approximate annual application rate*, t/ha
Application time
Method of embedding
for main tillage, in winter; for top dressing - autumn and spring; for spring plowing
under the plow
Winters on grain
spring harrowing
Table potatoes
under the plow
Forage potatoes
under the plow
Sugar beet (factory beet)
in the autumn and spring, under the spring tillage
under a plow or disc-tiller
Fodder and sugar beets for cattle feed
Corn for green fodder and silage
Perennial grasses and legume-cereal grass mixtures for hay and green fodder
after mowing
harrowing after mowing
after mowing
harrowing after mowing
at the end of the growing season, during fertilizer irrigation, after cattle grazing
harrowing at the beginning of the growing season
Annual grasses
in autumn under the plowing or in spring under the pre-sowing tillage
under a plow or disc-tiller
Rye for green fodder
for plowing or pre-sowing tillage
under plow, disc-tiller, cultivator, spring harrowing
Rye for green fodder
in winter for plant fertilization

Litter-free manure is mainly applied to crop rotation fields where it can be ploughed in. When used for perennial grasses, the highest yield increases are achieved with a combination of manure and mineral nitrogen fertilizers. Litter-free manure is applied primarily to row crops and perennial cereal grasses which have a long growing season and a high consumption of nutrients.

Average annual rate of applied manure, without fear of worsening the quality of crops and fodder, can be recommended equivalent to no more than 200 kg of nitrogen per 1 hectare. In irrigated agriculture – not more than 300 kg of nitrogen per 1 ha.

Features of crop applications


For table potatoes the dose of nitrogen applied with litter-free manure should be no more than 160-180 kg/ha, applied in autumn. For seed potatoes – 120-140 kg of nitrogen per 1 ha, which is 3/4 of the potatoes’ need for nitrogen. The rest part is introduced with mineral fertilizers.

Under forage potatoes with litter-free manure you can add the whole dose of nitrogen, i.e. 240-280 kg of nitrogen/ha. It is applied in autumn under plowing or in spring under tillage. Application of high doses of nitrogen for potatoes requires control of tuber quality.

Sugar and fodder beets

Sugar and fodder beets respond to high doses of nitrogen. The nitrogen requirement is met by 50-70% by litter-free manure, because some of the nitrogen and potassium can be washed out when applied in autumn on light soils. The rest of the nitrogen is applied with mineral fertilizers.

On black soils, nitrogen doses of unlettered manure should be no more than 300 kg/ha. At the same time control the quality of root crops, do not allow the accumulation of nitrates in fodder beets, as well as reducing the accumulation of sugars and the accumulation of non-protein nitrogen, which reduces sugar yield.


Corn for green fodder and silage is characterized by a high demand for nitrogen, which can be fully satisfied by litter-free manure. It is applied in autumn before plowing of furrow or in spring.

Perennial grasses

Perennial cereal grasses respond well to litter-free manure. Apply before sowing of the cover crop, in early spring and summer after each mowing. For the first cut of the first year, the dosage is 20 t/ha, 80 kg/ha of nitrogen. Grasses make good use of the aftereffect of manure applied under the cover crop.

The greatest effect is achieved by a combination of litter-free manure and mineral nitrogen fertilizers. For subsequent mowing, manure is applied within 10 days after the previous mowing. However, it is necessary to wait 20-25 days from application to use of grass in order to avoid accumulation of nitrates above permitted rate.

For legume-cereal mixtures, the dose of manure is reduced by half, as clover and alfalfa consume a lot of phosphorus and potassium, and nitrogen provides itself through nitrogen fixation. The excessive application of litter-free manure to grass mixtures with alfalfa or clover leads to weed overgrowth and thinnings.

Cereal crops

Nitrogen requirements of winter cereals can be met by 50-75% by litter-free manure and the rest by mineral nitrogen fertilizers, taking into account fractional nitrogen nutrition during the growing season. Litter-free manure is applied when preparing the soil for sowing winter crops. In spring, during the growing season, fertilization with litter-free manure or liquid fraction by sprinkling is carried out.

For spring grains, the litter-free manure is applied in autumn during autumn plowing and in early spring with embedding in the pre-sowing tillage. The dosage of nitrogen, as well as for winter crops, is determined by methods of diagnostics of nitrogen nutrition. Approximately 1/4 of the annual rate is compensated by mineral nitrogen fertilizers.

Vegetable crops

For vegetable crops in the open field, litter-free manure is used only for main application with the plow. It is not used for indoor crops.

Hayfields and pastures

Liquid organic fertilizers are applied several times in early spring and after each mowing or grazing to cattle. Spreader tanks or sprinkler systems are used for this purpose.

Semi-liquid manure on pastures is applied once a year in spring, after sod drying, using spreader tanks. Often it negatively affects quality of forage eatability, so after grazing it’s better to water with liquid fraction with sprinklers, then with water. It is necessary to keep sanitary terms of grazing – not less than 20-25 days after irrigation.

In hayfields and pastures combine application of litter-free manure with mineral fertilizers.

Application of increased rates of nitrogen in hayfields and pastures requires enhanced agrochemical and sanitary control of forage quality, especially the content of nitrates and potassium.


Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.

Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. – M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, 2017. – 854 с.

Fundamentals of Agronomy: Tutorial/Y.V. Evtefeev, G.M. Kazantsev. – M.: FORUM, 2013. – 368 p.: ill.


Manure is one of the most important types of organic fertilizers. It has a complex effect on the soil, replenishes the stock of mobile forms of nutrients in the soil, improves the circulation of macro- and microelements in the soil-plant system. A significant portion of the nutrients used by plants from the soil and from the applied mineral fertilizers, with feed and bedding goes to feed the livestock, passes into the manure, with which returns to the soil.

Importance of manure

The importance of manure is manifested through its effect on soil and cultivated plants directly and indirectly:

  • enriches the soil with nutrients, carbon dioxide in the soil and supra-soil air, microorganisms and organic matter;
  • improves physical-chemical properties and structure of soils;
  • increases cation exchange capacity (CEC), buffer, the degree of saturation with bases and the content of mobile forms of nutrients, reduces acidity and the content of mobile forms of aluminum and manganese;
  • improves soil fertility;
  • increases crop yields and the quality of agricultural products;
  • water and air regimes are improved.

Effects of manure on soil

According to generalization of A.D. Khlystovsky (1992), for 55-65 years on uncultivated sod-podzolic heavy loam soil of Dolgoprudny agrochemical experimental station named after D.N. Pryanishnikov, doses of litter manure on average 9 t/ha per year led to 2-fold increase in yields of winter rye and wheat and potatoes. D.N. Pryanishnikov doses of litter manure averaged 9 t/ha per year led to a 2-fold increase in yields of winter rye and wheat, potatoes, oats, and grasses compared with unfertilized control. The average annual productivity of the crop rotation was 2.3-2.6 t/ha of grain units and 2.8-3.0 t/ha of grain units at doses of 15 t/ha.

The application of bedding manure at the dose of 12 t/ha annually during 52 years had the neutralizing effect on soil acidity which was equal to 100 kg/ha CaCO3, reduced in the 0-20 cm layer compared to the control hydrolytic and exchange acidity on 0,5 mg-eq/100 g, aluminum content twice, increased the sum of absorbed bases on more than 1 mg-eq/100 g soil, saturation degree of bases – on 10%. Neutralizing effect of manure was also manifested in the subsoil horizon (20-40 cm).

Increasing the saturation of crops with manure and the transition to a systematic application of increasing doses improves agrochemical indicators, fertility and cultivation of poor sod-podzolic soil. In combination with the systematic application of high doses of lime turns poor soil into a fertile soil, which does not differ in agrochemical indicators from chernozems. However, as a rule, such a strong increase in fertility is economically unprofitable, environmentally dangerous. Taking into account economic opportunities it is advisable to increase the fertility of poor specific soils to the optimal level, ensuring the maximum productivity of crops of good quality with the scientifically sound application of fertilizers and ameliorants.

Table. Agrochemical indicators of soil in the state farm "Gribovo" at different degrees and duration of its fertilization with manure (V.A. Frantsesson)

Soil samples
V, %
Mobile P2O5
Exchange К2O
mg⋅eq/100 g of soil
Uncultivated (from under the forest)
A field (little fertilized with manure)
Household plot (systematically applied manure)
Garden (heavily manured)
Old garden (long and heavily manured)

Positive effect of manure on physical and chemical properties of soils is confirmed by numerous experimental data obtained in different soil and climatic zones of the country.

Under the influence of organic matter of manure, microbiological processes in the soil are activated, which increases the solubility and availability of nutrients to plants. Under the influence of microbiological processes that decompose fiber, the content of available forms of phosphate in red soil increased by 2-3 times. Under the influence of products of vital activity of microorganisms insoluble phosphates of calcium, iron, aluminum turn into soluble compounds. Manure affects the biological activity of soil, nitrification capacity and proteolytic activity.

Table. Comparative effect of systematic (7 years) application of manure and mineral fertilizers on water-physical properties of ordinary black earth[1]Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al; ed. by V.G. Mineev. - M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, … Continue reading

Experience options
Filtration capacity, mm/min*
Total moisture capacity, % of abs. dry soil**
Productive moisture, mm**
Water-permeable soil aggregates content 0.25 mm per abs. dry soil
Manure, 50 т/га
Manure, 100 т/га
NPK equivalent of 50 tons of manure
NPK equivalent of 100 tons of manure

Note. *For soil layer 0-10 cm.

**For soil layer 0-20 cm.

Manure is of particular importance in areas of the Non-Black Earth zone of Russia, whose soils are poor in humus and contain few nutrients.

Nutrient content of manure

The availability of nitrogen, phosphorus and potassium of manure to plants depends on the type and quality, soil properties and climatic conditions of the area. Manure contains all the necessary nutrients, but in different amounts and forms. Since plants consume mineral forms, their availability depends on the initial content of mineral forms and the rate of mineralization of organic forms of elements.

Total nitrogen of manure is assimilated by the first fertilized crop in 3 times worse than from mineral fertilizers, phosphorus – 1,5-2,0 times better, potassium – the same as from mineral fertilizers. Therefore, to obtain a high yield of crops with the introduction of manure, it is necessary to make additional nitrogen fertilizer.

For example, the total content in the half-digested manure nitrogen – 0,5%, phosphorus – 0,25%, potassium – 0,6% and the dose of application of 20 t/ha into the soil will be 100 kg/ha of nitrogen, 50 kg/ha of phosphorus and 120 kg/ha of potassium. In the first year the cultures assimilate respectively: nitrogen (30%) – 30 kg/ha, phosphorus (35%) – 17.5 kg/ha and potassium (60%) – 72 kg/ha at a ratio N : P2O5 : K2O equal to 1.7 : 1 : 4,1.

The vast majority of crops, with the exception of potassium-loving crops, consume more nitrogen, then potassium and least of all phosphorus to obtain good quality yields:

  • cereals 2.8 : 1 : 1 : 1.9;
  • grasses 3.5 : 1 : 3.0;
  • groats 3 : 1 : 3;
  • leguminous crops 5 : 1 : 2;
  • spinners 2.0 : 1 : 1 : 1.5.

Potassium-loving crops have a predominance of potassium over nitrogen intake, the N:P:K ratio being, respectively:

  • potatoes 3 : 1 : 4;
  • root crops 3-4 : 1 : 4-6;
  • sunflower 2 : 1 : 6-7.

The above data also indicate the need to supplement manure application with nitrogen fertilizers.


Nitrogen from organic compounds as a result of ammonification is converted into ammonium or nitrified to nitrates. Under conditions of high soil moisture and lack of oxygen in an alkaline environment, denitrification and formation of molecular nitrogen can occur, which is irretrievably lost to the atmosphere. When manure is handled properly, nitrogen losses through denitrification are dramatically reduced.

The nitrogen content and forms of nitrogen in the manure of each animal species are determined by the ratio of solid, liquid excreta and bedding material. Nitrogen from feces and litter contains slowly decomposing nitrogen compounds, so it is little available to plants in the first year, while urine is easily soluble, quickly transforming into ammonia and available to plants immediately after application. The more urine and ammonia the litter absorbs, the higher the content of total and ammonia nitrogen, so manure on peat litter or stored or covered with peat is most rich in total and ammonia nitrogen. In semi-prepared manure of dense storage the content of total nitrogen ranges from 0.3 to 1.0% depending on the type of animals and quality of feed, and of ammonia nitrogen – from 20 to 40% of total nitrogen, depending on the type and quantity of bedding.

In the first year, plants assimilate an average of 20-30% of the total nitrogen in the manure. This depends on the content of the ammonia form of nitrogen and on the ratio between soluble and protein nitrogen, the amount of carbohydrates in the manure, the time between application and the beginning of intensive consumption by crops. A large amount of carbohydrates promotes the development of microflora, which also consumes ammonia nitrogen of manure, so its assimilation by plants is less. When you apply manure in the pair or under the main autumn tillage, it decomposes more completely and the crops assimilate more nitrogen than in the presowing and spring application.

Compared with mineral fertilizers, the total nitrogen of the manure of the first culture absorbed by 3 times less, but provides nutrition for plants with this element of culture for 3-4 years, sometimes longer, depending on the dose, quality of manure, soil and climatic conditions.

Utilization of litter manure nitrogen in the first year is most significant (30% of total, on average) from sheep (goat) manure, less from horse (20%) and cattle manure (18%), minimum (10%) from pig manure, although with abundant fattening pigs nitrogen utilization in the first year may exceed 20% of total.

Plants assimilate nitrogen from sheep manure, which contains little water and a lot of nitrogen, the fastest.


Due to the organic matter of manure, microbiological processes in the soil are enhanced, resulting in increased solubility and availability of mineral nutrients to plants. Thus, insoluble phosphates of calcium, iron, aluminum turn into mobile forms. Phosphorus consumed by microorganisms and fixed in the plasma when they die off, passes into compounds assimilated by plants.

Increased mobility of insoluble phosphates can occur as a result of interaction with humic and other organic acids. Therefore, phosphorus applied with manure is more mobile. For example, in sod-podzolic soil phosphorus accumulated due to systematic application of manure in crop rotation is less bound by R2O3-type oxides of iron and aluminum than when applying mineral fertilizers. In poor organic matter gray soils manure partially prevents the fixation of residual phosphorus carbonates. Acidifying effect of nitrogen-potassium fertilizers in an alkaline environment is not manifested. Under these conditions, phosphorus accumulated from long-term application of manure is more mobile than phosphorus accumulated from the use of mineral fertilizers.

The main mass of residual phosphate accumulates in the upper soil layers (0-20, 20-40 cm). In some cases, penetration of phosphorus into deeper layers is observed.

The content of mobile phosphorus in the soil (according to Kirsanov) with the application of manure already in 4 years in the arable layer increased by 12 mg/kg compared with the control without fertilizers. In 52 years, the difference was at a dose of 9 t/ha of manure – 16 mg/kg, at a dose of 15 t/ha of manure – 24 mg/kg. At the same time, mobility of phosphate increased. In 40 years, similar changes in the content of mobile forms and mobility of phosphate were found in the subsoil horizon.

Most of the phosphorus in manure is in the solid excreta of animals and litter and is assimilated by the plant as they become mineralized. Organic matter of manure prevents chemical fixation of mineralized phosphorus in soil, allows it to remain in digestible forms for plants longer. Therefore, in the first year after the application of equivalent doses of phosphorus of manure plants assimilate 1.5-2.0 times more (on average 35% of total, sometimes up to 50-55%), than from mineral fertilizers.

Plant assimilation of phosphorus of manure, depending on its dose and quality, as well as soil and climatic conditions lasts 3-4 years. Moreover, the initial advantage of manure phosphorus over mineral fertilizers decreases over time.


Potassium in all components of litter manure is in mobile and plant-available forms. Potassium of manure is assimilated by plants in the first year in the same way as from equivalent doses of mineral fertilizers. Its total effect in the manure for an average of 3-4 years, with increasing doses and fertile soils – more than 4 years. Duration of potassium action of manure and mineral fertilizers in equivalent doses for several years is close or with some advantage of manure, depends on the cultivated crops, fertilizer doses and soil and climatic conditions.

Systematic application of manure and liming reduces the mobility of potassium, as it leads to its consolidation in the soil. In black soils due to nitrification processes that reduce the content of ammonium, and hence its competitive ability. The application of manure on black soils, as well as on sod-podzolic soils, contributes to the accumulation of exchangeable potassium compared with mineral fertilizers, at the same time increasing the processes of fixation of potassium in the non-exchangeable form. Exchangeable potassium in black soils is less mobile, and with the use of manure, its mobility decreases, whereas from mineral fertilizers – increases.

On gray soils, the systematic application of fertilizers leads to an increase in exchangeable and non-exchangeable potassium. Soil leaching regime contributes to the accumulation of these forms of potassium in the soil profile to a depth of 1 m. Differences in the effect of manure and mineral fertilizers are manifested in changes in the mobility of exchangeable potassium: against the background of manure mobility decreases, against the background of mineral fertilizers increases.

During 52 years, the average dose of manure of 9 t/ha increased, compared with control without fertilizers, the content of exchangeable potassium in the arable layer by 15-36 mg/kg, at a dose of 15 t/ha for 18-20 years – 31-52 mg/kg. In the subsoil horizon (20-40 cm) the content of exchangeable potassium in 40 years increased by 100 mg/kg, in 50 years – by 120 mg/kg.

In the first year the plants assimilate 60-70% of potassium introduced with the manure.

Carbon, calcium, magnesium, sulfur

The decomposition of organic matter in manure mineralizes at least 70% of the carbon, which is converted into carbon dioxide; the remaining 30% is spent on the new formation of humus. Carbon dioxide, dissolving in soil solution, increases mobility of soil phosphate and calcium, which improves plant nutrition with these elements, calcium also improves soil structure. For example, during decomposition of 30-40 tons of manure, 35-55 (according to other sources, 100-200) kg of carbon dioxide is emitted daily, which enriches the near-ground atmospheric air and improves air nutrition of plants. All stalked crops, for example, cucumber, zucchini, pumpkin, with a dense herbage completely absorb the emitted soil carbon dioxide. This is especially important for crops grown in indoor conditions. Cereal yields of 4.0-4.5 t/ha require 180-200 kg of carbon dioxide daily.

Yield gains from manure as a source of carbon dioxide, applied at a dose of 20-30 t/ha for vegetable and row crops, reach 30-40%. Application of 60 t/ha of manure to cucumbers on sandy loam soil increased yield by 43%, 20% of which was due to carbon dioxide from the decomposition of the manure. Additional carbon dioxide increased sugar beet root yield by 24% and sugar yield by 25%.

Availability to plants of calcium, magnesium, sulfur, trace elements from manure, as a rule, is not worse than from mineral fertilizers. The duration of assimilation depends on the dose and quality of manure, composition and productivity of crops, soil and climatic conditions.


Manure is a source of micronutrients. When it is applied, the soil is less impoverished with micronutrients when high yields are obtained than when mineral fertilizers are used. The content of micronutrients in manure varies widely.

Table. The content of micronutrients in the litter manure[2]Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al; ed. by V.G. Mineev. - M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, … Continue reading

Content, g/20 tons of manure

Source of soil humus

The content of humus in the systematically manured soil more than 50 years as compared with the control without fertilizers in 15 years was higher in the arable horizon by more than 0,2% of carbon, total nitrogen – by 0,02-0,05%, in the subsoil horizon (20-40 cm) carbon – 0,04-0,05% higher, nitrogen – by 0,02-0,05%.

In the conditions of intensive agriculture it is impossible to achieve a deficit-free balance of humus in the soil without the use of organic fertilizers. With the systematic application of manure in the rotation humus content increases on all types of soils. Mineral fertilizers have little effect on the accumulation of humus and nitrogen, as the source of humus in the application of mineral fertilizers are mainly root and crop residues.

Depending on the soil type, long-term fertilizer application affects humus and nitrogen accumulation differently. For example, on humus-poor sod-podzolic soils this process is more noticeable. The low humus content of gray soils allows you to increase the humus content of the soil through organic fertilizers. On humus-rich chernozem soils, fertilizers provide a smaller increase in yield.

The composition of humus in different soils changes little with long-term use of fertilizers, the increase in carbon content is accompanied by the accumulation of all groups of humus substances. The ratio between humic and fulvic acids is a characteristic feature of a particular genetic soil type. The lack of influence of fertilizers on this indicator is due to the fact that the group composition of humus is characterized by fully humified soil organic compounds. Fertilizers affect the organic matter of the soil, which is in the early stages of humification.

For example, on sod-podzolic soils in 36 years systematic application of manure increased the content of water soluble humus by 17-34%, on slightly leached chernozem – by 5-18%, on typical gray soil – by 23-50% compared with control. These mobile organic substances are in the early stages of humification and enrich the soil with available nitrogen compounds. In soils with low humus content, water-soluble humus was accumulated more in long-term application of manure.

Accumulation of mobile humus substances manifested with prolonged application of fertilizers also on black soils. This is explained by mobilization of humus in chernozem soils due to acidifying effect of mineral fertilizers. Thus, long-term use of manure and mineral fertilizers enriches soils poor in organic matter with total carbon and nitrogen and increases the content of mobile forms of organic matter in all types of soils in the early stages of humification.

When calculating the balance of humus in the soil organic matter formed by humification of manure, as well as formed by root and crop residues of plants is taken into account. Annual replenishment of humus in soils from stubble and root residues of crops depends on the soil and climatic zone, the biological characteristics of plants, yields. For example, in the Non-Black Soil zone after cereals the humus is replenished on the average by 0.4 t/ha, on chernozems of the European part – by 0.5-0.7 t/ha, in the Urals, Siberia and the Far East – by 0.3 t/ha. Row crops replenish humus reserves on average 2 times less than cereals. Perennial grasses on rainfed soils – by 0.5-1 t/ha, with irrigation – more.

Manure humification coefficient depends on soil and climatic zone, agrotechnique, irrigation, dry matter content in manure, type of manure. In general, it is 15-30% per dry matter. The coefficient of humification of plant residues of cereal crops and perennial grasses is equal to the coefficient of humification of litter manure, and that of tilled crops – half as much. Knowing doses of manure application in the crop rotation it is possible to calculate humus accumulation in the soil.

Annual humus mineralization depends on soil and climatic conditions, cropping pattern, intensity of tillage, and level of chemicalization. Soils under cereal crops annually lose 0.5-1 t/ha of humus; under row crops – 0.8-3 t/ha. Maximum humus mineralization occurs in clean fallows – up to 3-5 t/ha. Mineralization of humus is more on soils of light granulometric composition and with irrigation.

Introduction of organic fertilizers improves the nitrogen regime of soils, as 1 gramme of carbon is spent on fixation by microorganisms of 15-20 to 20-40 mg of atmospheric nitrogen.

Litterless manure is a source of easily soluble nutrients for plants, increases humus and nitrogen content in soil. However, the organic matter of litterless manure differs from littered manure and straw in composition and humus reproduction capacity. The C:N ratio in litterless manure has values from 5:1 to 10:1. Litterless manure is characterized by a high content of easily degradable organic compounds. Therefore, it has less effect on humus reproduction than litter manure.

Litter manure

Composition of manure

Litter manure consists of solid and liquid animal excreta and bedding. The excrements contain about 40-50% of organic matter and nitrogen, 60-70% of phosphorus and potassium of their initial content in the feed.

Table. Composition of litter manure[3]Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

Animal species
Number of excrements from 1 head of livestock per day
solids, kg
liquid, l
ratio of solids to liquids
- adult
- juveniles up to 1.5 years old
- calves up to 6 months old

The composition of litter manure depends on the amount, ratio of solid and liquid excreta of animals and litter, which in turn are different for different species (and age) of animals.

Horses, sheep and cattle have more solid excreta than pigs. Solid and liquid excreta are unequal in composition and fertilizer value: more than 95% of phosphorus is contained in solid, 50 to 75% of nitrogen and more than 80-90% of potassium in liquid excreta. The content of dry matter in animal excreta is on average about half of the dry matter of feed, and the content of nitrogen and ash elements can be 1,5-2,0 times higher than in feed.

When concentrated feeds with higher digestibility than hay are introduced into animal diets, the excreta will contain less dry matter and the nitrogen and phosphorus content will be higher.

Table. Content (%) of dry substances and nutrients in solid and liquid excreta of animals[4]Yagodin B.A., Zhukov Yu.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

Animal species
Dry matter
< 0,01
< 0,01
< 0,01

The excrements of cattle and pigs contain less dry matter and nutrients than those of horses and sheep. Therefore, the excrements of sheep and horses decompose faster, give out a lot of heat during storage, and the manure of these animals is called hot, pigs and cattle – cold. Hot manure is used to fill greenhouses, to make insulated beds, and as biofuel.

Quality of manure depends on conditions and duration of storage: during long storage the relative content of nitrogen, phosphorus, potassium increases as a result of decomposition of organic matter. Due to the fact that the chemical composition of manure varies, it is desirable to determine the chemical composition of manure before application in order to correctly determine the dose. Otherwise, reference data is used.

Nitrogen, phosphorus and sulfur in solid excreta of all animals are part of various organic compounds and become available to plants only after mineralization. In liquid excreta all nutrients are in easily mineralizable and soluble forms, and quickly under the influence of microorganisms become available to plants. Potassium, calcium, magnesium in solid and liquid excreta are in mobile, assimilable forms for plants.

Solid excreta are rich in microorganisms: up to 30% of the total mass, while liquid excreta may not contain them at all, but mixed with solid ones, they are quickly enriched with microorganisms present in the environment.

Manure quality and chemical composition depend on type of feed, ration, type of animal, amount and type of bedding, and storage method. For example, when fattening animals with a large amount of concentrated feed in the diet, the manure has a high content of nutrients compared with the manure of animals receiving silage, root crops and coarse fodder with high fiber content. About 40% organic matter, 50% nitrogen, 80% phosphorus and 25% potassium are transferred from the feed intake to the manure.

Table. Chemical composition of fresh manure on straw litter[5]Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al; ed. by V.G. Mineev. - M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, … Continue reading

Organic matter
Nitrogen (N) total
- protein
- ammonia
Phosphorus (P2O5)
Potassium (K2O)
Lime (CaO)
Magnesia (MgO)
Sulfuric acid (SO3)
Silicic acid (SiO2)
Al and Fe oxides (P2O3)


The quality of manure depends on the chemical composition and absorption capacity of litter, which favors conditions for microorganisms and fecal decomposition. The litter’s ability to absorb liquids and gases is important. The quality of manure depends largely on the nitrogen and ash content of the litter. The highest nitrogen content is characteristic of peat litter and legume straw, the latter also contains the highest amount of phosphorus.

The best litter material is highland peat. It has a small ash content (1.5-3%), a high ability to absorb liquids and gases: 1 kg of highland peat can absorb 9-18 kg of water, 15-30 g of ammonia, while 1 kg of straw – 2-3 kg of water and 2-5 g of ammonia. The use of peat litter in livestock yards reduces the concentration of ammonia and carbon dioxide in the air by 2.5 times and reduces the relative humidity of the room from 100 to 75%. Peat litter improves zootechnical conditions of cattle housing and increases manure yield, reduces nitrogen losses. An increase in litter up to 8-10 kg per day increases the yield of manure and nitrogen losses are reduced to zero; 1 ton of dry peat litter provides an additional 5-7 tons of manure with high nitrogen content.

It is better to use chopped straw for litter up to 10-15 cm, as it contributes to better absorption of urine, homogeneity of manure, its uniform distribution in the field and ploughing. Efficiency of manure on chopped straw litter is 20-30% higher than manure on whole straw litter. If there is a shortage of straw and high-moor (sphagnum) peat, dry peat crumbs of transitional or lowland peat with a degree of decomposition not exceeding 25% and humidity not exceeding 40-45% are used as litter.

Using sawdust as litter produces low quality manure with little nitrogen content, but large amounts of slowly decomposing fiber. Such manure is better suited as biofuel in indoor vegetable production, the following year for field crops.

Litter is part of the manure, increasing its quantity, and affects, depending on the type and quantity on the chemical composition and loss of nutrients. Litter absorbs liquid excreta of animals and ammonia formed during decomposition of urine, reducing the loss of nitrogen, potassium and other soluble substances and gases. Litter reduces the moisture content of excreta, making them more friable, which facilitates their microbiological decomposition, facilitates loading, transportation, application and embedding.

Litter materials differ in nutrient content and absorption capacity.

Table. Average content (%) of water, nutrients and absorption capacity of litter materials[6]Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

Вид подстилки
H2O, т/т
NH3, г/кг
Straw of:
- cereals
- legumes
- lowland
- raised
Tree leaves
Sawdust wood

Peat and straw have the highest absorption capacity, and peat contains more nitrogen than cereal straw. Manure on straw litter is called straw litter, on peat litter – peat (peaty) manure.

When peat and straw are scarce (or absent), and for hygienic and economic reasons, leaves and sawdust may be used as litter. The quality of manure deteriorates: fiber and lignin content increases, with sawdust additional nitrogen content decreases. Such manure takes longer to decompose and is less effective in the first year after application.

The best litter is high-moor peat with a degree of decomposition up to 25-30% and moisture content of 30-40%. More decomposed and moist peat absorbs less liquid secretions, drier peat absorbs poorly and takes a long time to be wetted. The advantage of high-moor peat over transitional and low-moor peat is also due to its more acidic reaction, which suppresses pathogens (anthrax, brucellosis, paratyphoid, E. coli pathogens).

Average daily norms of litter materials per 1 head of livestock depends on the type of animals, quantity and quality of feed consumed and logistical capabilities.

Table. Average daily doses of bedding (kg) per 1 cattle (data from All-Russian Institute of Fertilizers and Agrochemistry)

Animal species
Cereal straw
Raised peat
Peat crumb (transitional, lowland)
Sawdust, wood shavings
- adults
- calves
Sheep, goats

With an increase in the ration of succulent feed, such as green mass, root crops, silage, the amount of litter increases, with an increase in the proportion of concentrated feed – reduce. The amount of manure depends on the type of animals, length of stabling period, quantity and quality of feed and bedding materials, terms and methods of manure storage.

Calculation of litter manure yield

The amount of manure accumulated on a farm is determined by the number of livestock, the length of stabling period, and the amount of litter and feed. Low manure yields are often associated with low application of litter, poorly organized collection and storage of manure. The use of straw for litter leads to increased accumulation of manure, increasing its quality and improving zoohygienic conditions of animal housing. With abundant feeding cows with an average annual milk yield of 4000-4500 kg of manure with daily use of 20 kg of lowland peat in the litter is 11-12 tons of one cow per year.

According to the data of the All-Russian Institute of Fertilizers and Agrochemistry, during 200-day stabling period 7 t of straw manure and 8 t of peat manure are received from 1 cattle head at daily dose of 2 kg of litter. At the same time, nitrogen losses for 3.5 months of storage from the first one amounted to 44%, from the second one – 25%. With an increase in daily litter norms to 4 kg for the same period the yield of straw manure was 8 tons, peat manure – 9 tons, nitrogen losses for the period of storage from the first was 31%, from the second – 14%. Increasing daily litter rates to 6 kg increased the yield of straw manure to 9 tons, peat manure to 10 tons, reduced nitrogen losses during storage from the first to 13%, from the second to 3%.

The amount of manure decreases as the stable period decreases.

Total yield of fresh manure in the farm is approximately determined according to the table with further recalculation on the number of animals.

Table. Approximate yield of straw manure (t) from one head of cattle at different duration of stabling period[7] Yagodin B.A., Zhukov Yu.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

Animal species
Duration of stable period, days
less than 180
Sheep, goats

The yield of manure H can be calculated using Wolf’s formula:

Wolff's formula

where K/2 is half of the dry matter of fodder transferred to manure; W is the dry weight of litter; 4 is a coefficient showing that the water content of manure is 4 times greater than the dry matter of fodder and litter.

There are also other ways of calculating manure yield. For example, in France, the amount of manure is determined by multiplying the weight of the herd by a coefficient of 25.

The amount of manure varies depending on how and how long it is stored. When manure is loose, in 3-4 months manure loses 33-50% of dry matter, when it is tight – only up to 10%. Volume weight of manure also varies depending on method of stacking and degree of decomposition: without compacting fresh weight of 1 m3 is 300-400 kg, in compacted state – 700 kg/m3, half-decomposed manure – 800 kg/m3 and highly decomposed – 900 kg/m3.

Manure storage times

Manure, depending on the terms and conditions of storage, the degree of decomposition of organic components acquires the appropriate appearance and consistency.

There are four stages of straw manure decomposition: fresh, half-decomposed, decomposed and humus.

Fresh, or slightly decomposed, straw manure slightly changes color and strength.

Half-decomposed manure – straw becomes dark brown in color, loses strength, and tears easily. From decomposition, manure loses 10-30% (on average 25%) of its weight and dry organic matter.

Decomposed manure is a homogeneous mass, straw decomposition reaches a state where individual straws cannot be detected. Weight loss from decomposition reaches 50% of weight and dry organic matter.

Humus – loose dark mass, losses from decomposition are up to 75% of the original weight and dry organic matter.

Table. Content of nitrogen and phosphorus in cow manure prepared on straw litter, depending on the degree of its decomposition, %[8]Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. - M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, 2017. - 854 p.

Degree of manure decomposition
Nitrogen (N)
Phosphorus (P2O5)
Losses of organic matter

Manure should not be reduced to decomposed manure or humus because long-term decomposition reduces the amount of organic matter by a factor of 2 to 3, while the percentage of nitrogen and phosphorus increases much less.

The best manure for plowing is half-decomposed litter manure.

Table. Chemical composition of half-decomposed litter (State Agrochemical Service Centers and Laboratories)

Type of manure
Content at natural humidity, %
Humidity, %
nitrogen (N)
phosphorus (P2O5)
potassium (K2O)
organic matter

Manure storage methods

Depending on the methods of accumulation and storage of manure prior to application to the soil, the processes of decomposition of organic matter and the extent of loss of nutrients vary.

There are the following ways of manure storage:

  • loose, or hot, in which manure is not compacted;
  • hot-pressed, or the Kranz method, when loose manure is compacted after heating to 50-60°;
  • cold, or dense.

Table. Average losses of organic matter and nitrogen at different methods of manure storage for 4 months (data from All-Russian Institute of Fertilizers and Agrochemistry and Research Institute of Fertilizers and Insectofungicides), %

Manure storage method
Manure on straw litter
Manure on peat litter
organic matter
organic matter

Dense (cold) method of manure storage

Dense, or cold storage, is stacking manure in a manure storage facility or in field stacks in layers 5-6 m wide and 1 m high, the length depending on the size of the storage facility and the quality of the manure, with immediate compaction. On top of the compacted layer, subsequent layers are stacked and compacted until the height of the layers reaches 2.5-3.0 m. The compacted stack is covered with a layer of 8-15 cm of peat, chopped straw or soil on top. On the side, close to the first one, lay and compact the second stack until the whole manure storehouse is filled. The width of the stack should be at least 5-6 m.

The dense method of storage is the best because the greatest amount of nutrients is retained.

In compacted manure in winter the temperature does not rise above 15-25 ° C, in summer – 30-35 ° C. All pores of manure are maximally saturated with carbon dioxide and water, which slows down microbiological activity and prevents loss of ammonia, water and carbon dioxide. Free ammonia is bound by carbon dioxide solution (carbonic acid) and organic acids. Due to this, the best preservation of organic matter and nitrogen is achieved and the amount of slurry in this storage method is minimal. Half-decomposed manure is stored in winter in 3-4 months, and decomposed manure is stored in 7-8 months after stacking.

This storage method requires manure storage facilities.

Storing manure under livestock is a kind of dense storage method. It is used when animals are kept without restraint in field pens, in the paddocks and in livestock buildings. For this purpose, peat or straw is spread over the entire area with 30-50 cm layer. Litter is mixed with animal excrements and compacted by them. If the top layer is sufficiently moistened, the next layers of litter are added. By abundant and timely addition of litter materials, liquid excreta (and slurry) is preserved in manure, which reduces nitrogen and organic matter losses. This method of accumulation and storage during winter time keeps animals warm and makes it easier to care for them. It also reduces the cost of manure because it reduces the cost of manure removal, construction and maintenance of manure storage and slurry collectors. Half-decomposed manure can be removed and applied to the soil 2-3 times a year.

Manure in dense storage contains a significant amount of ammonia nitrogen, but in straw litter it is somewhat less. Protein nitrogen content increases as a result of its binding by microorganisms.

Loose-dense (hot-pressed) storage

It is used for rapid decomposition of, for example, high straw manure, or for biothermal destruction of weed seeds and gastrointestinal pathogens, which are often found in pig and sheep manure.

Fresh manure is placed in manure storehouses in a loose layer up to 1 m high; it is covered with straw or peat for the winter to keep warm. Microbiological processes in aerobic conditions result in rapid decomposition of organic substances, and when temperature rises to 60-70 ° C (usually on the 4th-6th day), it is compacted, then the next loose layer is placed on it, which also when reaching 60-70 ° C is compacted, and so on. Stacking continues until the height of the stack of 2-3 m. After compaction, the temperature drops to 30-35 ° C, and decomposition corresponds to the dense storage.

This storage method produces a large amount of slurry, half-decomposed manure is formed in 1.5-2 months, decomposed manure – in 4-5 months.

Loose (hot) storage

Loose, or hot, storage is rarely used because it is accompanied by large losses of nitrogen, organic matter, and slurry. The poor quality of manure during such storage is due to the unevenness of decomposition: usually it is strongly decomposed inside the piles, but it dries out at the edges and remains poorly decomposed.

Biochemical processes occurring during manure storage

During the storage of manure, numerous biochemical processes take place in it under the influence of microorganisms. Liquid excreta of animals contain easily mineralizable nitrogenous compounds – urea, hippuric acid and uric acid, the rate of decomposition of which decreases from the first to the last.

Under the action of urease enzyme produced by urobacteria, urea is converted into ammonium carbonate:

СО(NН2)2 + Н2O → (NН4)2СO3,

then, to ammonia, carbon dioxide, and water:

(NН4)2СO3 → 2NН3 + СO2 + H2O.

Hippuric acid decomposes into benzoic acid and aminoacetic acid:


the latter into oxyacetic or acetic acid and ammonia:


Uric acid, often already in the mammalian body, is broken down to release carbon dioxide and allantoin (glyoxyldiureide):

C5H4N4O3 + 0,5O2 + H2O = CO2 + C4H6N4O3,

the latter decomposes to form glyoxylic acid and urea:

C4H6N4O3 + H2O = HCOCOOH + 2CO(NH2)2.

Мочевина – по ранее описанной схеме.

All nitrogen compounds of liquid excreta separately (in slurry) and as part of the manure decompose to ammonia. Peat, due to its increased acidity and exchange-absorption capacity, significantly reduces nitrogen losses by absorbing the resulting ammonia:

[Peat]H2 + 2NH3 → [Peat](NH4)2.

Nitrogenous compounds of solid animal excreta and litter undergo ammonification, but much slower due to the content of fiber and easily degradable carbohydrates (pectin, pentosans, starches, sugars), which serve as energy material for microorganisms. The rougher the animal feed and the more straw it contains, the more easily decomposed nitrogen-free compounds and fiber, respectively, the more nitrogen is fixed by the microorganisms.

Decomposition of nitrogen-free organic matter in aerobic conditions proceeds with an increase in temperature to 50-70 °C. Fiber under the action of bacteria in aerobic conditions decomposes into carbon dioxide and water:

6Н10O5)n + nН2O + nO2 = n(6СO2 + 6Н2O),

under anaerobic conditions to carbon dioxide and methane:

(C6H10O5)n + nH2O = n(3CO2 + 3CH4).

The content of fiber in manure can reach 30-36% in terms of dry matter, pentosans – 14-16%, which decompose during storage of manure. In case of loose manure storage, cellulose is decomposed by half, in case of dense manure – insignificantly. During manure decomposition oil, acetic acid and other organic acids are also formed.

Speed of decomposition of organic matter in manure depends on humidity, temperature, access to oxygen, i.e. degree of aeration, chemical composition of manure. The higher the aeration, the faster and at higher temperature decomposition occurs. A higher content of easily degradable organic matter promotes faster fermentation processes.

Nitrification and denitrification of nitrogen in manure does not occur because nitrification bacteria in aerobic conditions die at high temperature and cannot exist in anaerobic conditions. Also, high concentrations of ammonia and increased content of soluble organic compounds have a detrimental effect on them. In the absence of nitrates, denitrification does not occur.

Nutrient losses during manure storage

During manure decomposition there are losses of nitrogen and phosphorus, especially during loose storage. The amount of water-soluble phosphoric acid in this case increases from 7 to 25-30%, and soluble in 0.05 N HCl – from 30 to 80-85% of the total content. Phosphorus as a part of organic compounds in the decomposition of manure passes into mineral form. Under anaerobic conditions, the decomposition of manure may be accompanied by the formation of phosphorus hydrogen, or phosphine, (PH3), a gaseous phosphorus, an analog of ammonia, with which phosphorus losses are partially associated.

Potassium of manure is almost not lost during storage. Thus, during loose storage in a water-soluble state, it contained 85%, mixed – 91%, dense – 93% of the original content in fresh manure. During decomposition in the soil, potassium is consumed in small amounts by microorganisms and remains in compounds available to plants. Calcium and magnesium are bound by acids formed during the activity of microorganisms.

It is possible to reduce the loss of organic matter and nitrogen during storage by adding 2-3% by weight of simple powdered superphosphate.

Adding phosphate meal during manure storage is a way to effectively use the fertilizer on neutral soils, where phosphate meal alone is ineffective. Under the influence of carbon dioxide solution (carbonic acid) and organic acids formed during the decomposition of manure, three-substituted phosphates are converted into weak acid soluble and plant-accessible forms:

Ca3(PO4)2 + 2H2O + 2CO2 → 2CaHPO4 + Ca(HCO3)2.

In experiments of the All-Russian Institute of Fertilizers and Agrochemistry with different crops on sod-podzolic loamy soil, application of manure enriched in storage (composted) with phosphate flour (3% of weight) under potatoes and winter rye in action, and under spring wheat and perennial grasses afterwards, provided increased yields of these cultures compared with their joint application in the same doses without premixing (composting).

Phosphorite meal in an amount of 1-4% of the weight of manure (10-40 kg/t) or according to the needs of the crop, can be added to the manure at any time from the moment of its receipt, but the earlier, the better. For maximum effectiveness, it is most effective to add it in the stalls before harvesting or, in loose housing, immediately after the first layer of bedding material is applied. In the process of manure removal, transportation and stacking, complete mixing and interaction of flour with manure is achieved, in loose housing this process is facilitated by the animals themselves.

Peat litter and dense manure storage methods are the main methods of reducing losses of organic matter, slurry and nitrogen.

An available technique to increase manure yield while reducing losses of organic matter, slurry and nitrogen even during dense storage is increasing doses of bedding materials, manure storage facilities with slurry collectors, chopping straw and using peat.

Table. Losses of organic matter and nitrogen in 4 months after the beginning of manure storage with the addition of phosphoritic flour and superphosphate (%)

Organic matter
Manure + 3% phosphoritic flour
Manure + 2% superphosphate

Manure storages

Litter manure can be stored in manure storages and on special sites in stacks.

Manure storages can be:

  • above-ground type, used when groundwater is close to the ground;
  • excavated type.

The above-ground type is preferred because it is not flooded by precipitation and meltwater.

The requirements for manure storage facilities are:

  • The manure storehouse must be located on elevated, non-floodable, preferably surrounded by trees and approved by the sanitary and epidemiological stations of the relief.
  • It should have a waterproof bottom and walls which can withstand the pressure of loading and unloading machines, watertight slurry collectors located taking into account bottom slopes, convenient access, entry and exit with appropriate slopes, usually on narrow sides of the storehouse.
  • Dimensions depend on livestock population, volume of manure per cubicle period and stacking height. For 1 cattle, when stacked at a height of 1,5 m for 3 months, the manure storage area for cattle – 2,5 m2, including young cattle – 1,5 m2, for horses – 2,0 m2, pigs – 0,8 m2, sheep and goats – 0,3 m2.
  • When manure is removed twice during the winter period the area is halved. The volume of slurry tank shall be not less than 3-4 m3, their number shall be determined on the basis of 1,3 m3 per every 100 tons of manure.
  • Manure storehouse shall be located 50 m away from livestock yard; away from other buildings and drinking water sources – at least 200 m.
  • To collect the slurry a well is made at the distance of 1,5-2 m from the manure storage. The walls are lined with bricks on cement. The well must be equipped with a hatch with two wooden lids. 
    If there are infectious diseases of animals or if the manure contains seeds of quarantine weed plants, storage and use of the manure is allowed according to instructions of veterinary and quarantine services.

Stacks are stacked so that manure with different degrees of decomposition is not mixed. For this purpose they are stacked at one end across the storehouse, then at one end there will be stacks with decomposed manure (first stacks), further to the other end – all less decomposed stacks.

There are 8 variants of open manure storages with capacities of 3,20 and 4,25 thousand tons of litter manure with two sumps and two slurry collectors of 20 m3 capacity designed for six months of storage. For regions with excessive moisture content and precipitation of more than 600 mm, there are 4 variants of covered two-sectional storages for 2,2 and 3,1 thousand tons of litter manure. Two sections are provided for quarantine curing of manure for 5-6 months.

There are also some variants of on-farm concrete sites for solid storage of manure in stacks of 5-6 m width and 2,5-3,0 m height divided into sections: for manure, peat, for their mixing and solid storage of mixture (compost).

All projects envisage mechanization of works on removal, mixing, transportation, stacking and compaction of manure. For organizational and economic reasons, storage of manure in field stacks is also practiced.

Manure is removed to the field in winter because machinery is freer at this time. However, it is possible to remove manure in the field at any time of the year. The manure is removed from manure storages, barns, and farms and stacked in the field in winter for 1 day, otherwise it will freeze, which reduces the fertilizer value. Select areas in the field on high ground, cleaned of snow, covered with peat or chopped straw layer of 20-25 cm, top manure is covered with peat or straw. Stacking is carried out in stacks 3-4 m wide, 1.5-2.5 m high, which are arranged in rows at distances (D, m):

where 10000 – area of 1 ha, m2; Q – quantity of manure, t/ha; W – working width of the spreader; C – carrying capacity of the spreader, t.

Distance between stacks in a row D2:

where S – stack mass, t; W – working width, m; C – carrying capacity of the spreader, t.

In order to destroy germinating seeds of weeds, the surface of the piles is treated with herbicides.

One should not store manure in small piles, as this causes nitrogen losses up to 35-40 percent, it freezes, is washed by meltwater in spring, the field is fertilized unevenly, and spring treatment is complicated.

If cattle are not tied down and there is sufficient litter, manure is removed from farms, yards and grounds with simultaneous application to crops. More frequent removal when stored under livestock is carried out only when there is a lack of litter materials.

After spreading manure over the field, its embedding is carried out, because when stored in a scattered form, it dries out and nitrogen losses increase sharply.

Manure application

Manure in crop rotation

Manure application is distributed by crop rotation and non-rotation plots in the order of:

  • vegetable;
  • forage (on-farm);
  • field, taking into account specialization on the most valuable crops and remoteness from farms, pastures and grounds.

Within each agrocenosis, doses and place of application are determined taking into account unequal responsiveness of crops and aftereffects, organizational and technical possibilities for application and embedding into the soil, economic efficiency and environmental safety.

Vegetable crops are characterized by the greatest demand for soil fertility (5th class). Stemming cucumber, zucchini, pumpkin, melon, as well as onions, garlic, cabbage, cauliflower, green crops and radishes respond better to organic fertilizers than minerals.

Forage crops are most often located near farms (in on-farm rotations), so transportation and application costs are minimal. Responsiveness to organic fertilizers compared with mineral fertilizers is higher in corn, annual and perennial grasses, fodder root crops.

In field crop rotations corn for grain and sugar beet respond better to it. In field crop rotations, manure is also used for potatoes and winter cereals. However, according to long-term (over 50 years) field experiments Dolgoprudny agrochemical experimental station, at equivalent doses of nutrients, manure and mineral fertilizers for potatoes are of equal value, with winter and spring cereals manure inferior to mineral fertilizers.

In the Non-Black Soil zone, a good place to apply manure in the crop rotation is winter cover crops. At the same time, productivity of crop rotation increases from increasing the yield of winter, perennial grasses and following crops.

On acidic sod-podzolic soils in the main application of manure is combined with liming and the application of mineral fertilizers. It is better to apply manure under row crops, if spring cereals with undersowing of grasses are placed behind them in the rotation. On black fallow in the southern part of the Non-Black Soil zone, manure is applied during the plowing of fallow at a depth of 15-20 cm in early fallow – before tillage.

On sod-podzolic soils, when applied to sugar beet and fodder, potatoes, corn and other crops, manure is supplemented with nitrogen fertilizers, light sandy and sandy loam soils – nitrogen and potassium, irrigated ordinary black soils and chestnut soils – phosphorus fertilizers. The combination of manure and mineral fertilizers in the rotation creates more favorable conditions for plant nutrition and improves soil properties. Organic and mineral fertilizers are of equal value when used in equivalent doses of nutrients. On sandy soils some advantage has manure, as it helps to improve their properties. Therefore, when distributing to the fields, it is advisable to apply manure to the near field, mineral – to remote fields.

In crop rotation, it is better to apply manure under fallow-seeded crops, especially if it is a row crop. It is applied in autumn by plowing. If a fallow-seeded crops is early harvested, the manure is applied after it is harvested by plowing, and the field is prepared for sowing of winter crops as half-fallow. Manure is applied to spring crops in autumn under autumn plowing.

On light sandy and sandy loamy soils, especially in areas with sufficient moisture, a good effect gives a spring application of manure. However, in steppe areas, application in spring reduces the efficiency by 1.5-2 times compared with the application under autumn plowing.

With the increase of the share of row crops in the crop rotation the payment of manure as an additional yield increases. The place of manure application in crop rotation has little effect on productivity. However, it is slightly higher when applied to highly productive row crops such as sugar beets, potatoes, corn, because these crops most fully use the nutrients of manure in the first year.

The most qualitative application and incorporation of manure of crop rotation is carried out in bare and seeded fallows, as well as after early harvested predecessors.

Manure application rates

To determine the norms for the application of manure for the planned yield in the rotation or under the crop to calculate the balance of nutrients using the average data on the content in the half-decomposed litter manure: nitrogen – 0,5%, P2O5 – 0,25% and K2O – 0.6%, that is, 1 ton of manure – 5 kg of nitrogen, 2.5 kg of P2O5 and 6 kg K2O.

Norms of manure application depend on quality, methods of application, biological characteristics of crops and planned yields, soil and climatic conditions. Thus, in the northern, northwestern cold and humid areas, on poorly cultivated soils use higher doses than in the south, south-east, on the highly cultivated black soils. The rates should be economically profitable and environmentally friendly.

Table. Yield increments of the first and subsequent crops of the crop rotation at different doses of manure (according to the All-Russian Institute of Fertilizers and Agrochemistry)

Norm of manure application for the first crop, t/ha
Increase in increment with growth of manure application norm, %
Winter wheat
Spring wheat

Minimum rates of manure application on poor (poorly cultivated) soils at pre-sowing (main) application by continuous method with embedding to the depth of tillage in areas of sufficient and excessive moisture are 20 t/ha, on fertile cultivated soils and in areas of insufficient moisture – 10 t/ha. At local main application in furrows or rows the minimum doses are reduced by 2 times, at local application in wells – by 4 times. Localization and reduction of doses at any method of application increases payment for the unit mass of manure by yield increase of the first fertilized crop in all soil and climatic zones.

On light poor soils the increase is 1.5-2.0 times and the payment per ton is 2-3 times higher than on loamy more fertile soils. Local application of twice smaller doses provides under the first crop the same increase in production as a twice larger dose at continuous application, the payment of manure in this case increases by 2 times.

With the increase of application rates the payback decreases. Thus, the greatest effect will be obtained by applying manure on 2 hectares at 30 tons/ha than on 1 hectare at a dose of 60 tons/ha.

With the increase of manure application rates the increment of both the first and subsequent crops increases. Therefore, evaluation of manure dosage effect is carried out for all years of reliable effect on all crops of crop rotation. In all soil and climatic zones with increasing doses of manure the effect is more significant than the direct effect.

Systematic application of small and increased doses in any crop rotation from rotation to rotation increases the difference in application efficiency due to increasing aftereffect of increased doses.

With any provision of manure and other organic fertilizers within the agrocenosis optimal doses are set after a preliminary assessment of the cost effectiveness of possible options.

The poorer the soil and the higher the planned yield and productivity of the rotation, the more effective high doses of organic fertilizers.

Cereal crops require lower doses of manure compared to row crops such as potatoes, corn, sugar and fodder beets. Hemp, silage crops, cucumbers, and late cabbage varieties respond well to higher doses.

Таблица. Средние дозы органических удобрений (т/га) под овощные культуры (Научно-исследовательский институт овощного хозяйства)

Sod-podzolic loamy soil
Floodplain loamy soil
5th grade
6th grade
5th grade
6th grade
White cabbage (medium and late)

Rates for applying organic fertilizers increase with the growth of the planned yields. For the central regions of the Non-Black Soil zone of Russia differentiated by yield levels doses of organic fertilizers for the most responsive crops are recommended.

Table. Rates applying of organic fertilizers (t/ha) depending on the planned yield of crops on non-black earth soils of Central Russia[9] Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

Crop, production
Planned yields, t/ha
Rate of application of organic fertilizers
Root crops
< 25
> 50
Medium and late cabbage, cabbage heads
< 40
> 60
Silage crop, green mass
< 25
Potato, tubers
< 16
Winter cereals, grain
< 3,5
> 3,5

The maximum application rates in a particular case should be economically justified, i.e. should provide the planned yields of good quality and expected profit, and environmentally safe, i.e. the amount of nutrients should meet the needs of cultivated crops while maintaining optimal soil fertility properties, contamination of adjacent environments is not allowed.

Fractional doses of manure for several crops in a crop rotation do not show advantages over a single application for one crop. In multi-row crop rotations with several row crops the efficiency increases if high doses calculated for deficit-free or positive humus balance are applied under 2-3 intensive crops of the rotation.

Various spreaders are used for manure application.

Organic fertilizer spreader РОУ-5
Organic fertilizer spreader РОУ-5: 1 - chain-plank conveyor; 2 - shredding drum; 3 - spreading drum; 4 - protective gear casing; 5 - overhang of the body; 6 - support; 7 - crank; 8 - suspension

Efficiency of manure

In all agricultural zones of Russia, the most effective is half-decomposed manure obtained by the dense method of storage. Bringing manure to humus is inexpedient because it is associated with large losses of nitrogen, phosphorus and organic matter. Fresh manure is also not used as it contains seeds of weeds and disease-causing agents, a large number of undecomposed nitrogen-free compounds which strengthen the immobilization of nitrogen, phosphorus and other elements, thus acting as a competitor of plants. Therefore, crops sown on fresh manure in the first year can reduce yields due to nitrogen-phosphorus starvation at the beginning of the growing season. It is unacceptable to apply fresh manure to sugar beets, corn, and winter wheat if it is not sown on bare fallow.

As you move from the northwestern and western regions of European Russia to the eastern and southeastern regions, the efficiency of organic fertilizers decreases, although it remains high. In the arid southeastern zone, the effect of manure is often higher than the direct effect.

If a farm has manure with different degrees of decomposition, more decomposed manure in areas with sufficient moisture is introduced in the spring for row crops, less decomposed – in the fallow for winter crops. In arid steppe regions all types of manure are applied under autumn autumn plowing. In areas of excessive moisture, especially on light soils, the effective application of manure for spring crops in the spring pre-sowing tillage.

In the Non-Black Soil zone, half-decomposed manure is used more often; when applied in the fall, fresh manure is also effective.

In different soil and climatic zones each ton of manure when properly used in all years of rotation provides an additional production of 100 kg per grain. Under irrigation conditions on black and chestnut soils, yield increases proportionally to doses of manure because plants use nutrients more fully when sufficiently supplied with moisture.

Early varieties responsive to organic fertilizers and crops with short growing season in all zones fertilize with more decomposed manure, late – less decomposed.

Effectiveness of manure under the first crop is greatly reduced with increasing time between application and incorporation into the soil as scattered and not incorporated manure loses its ammonia within 10-20 hours.

Depending on soil-climatic conditions and degree of decomposition, the depth of manure incorporated into soil during pre-sowing application varies from 15 to 30 cm. Shallow embedding in wet soil promotes decomposition of manure. If there is a lack of moisture in dry conditions, shallow incorporation slows decomposition and dries out the soil even more. On soils with a heavy granulometric composition, relatively shallow embedding is necessary, on light soils, deeper embedding is necessary.

On sandy soils, which are highly permeable to water and air and warm quickly, the manure decomposes intensively. In this case, some of the nutrients may be washed away. On these soils, manure is applied in small doses to several crops in a crop rotation. Higher doses are applied on clay and loamy soils, because on such soils it decomposes slowly and increases the yield over a number of years.

After-effects of manure

The effectiveness of manure on the first and following crops of the crop rotation decreases with the transition from poor to fertile soils, as well as with a decrease in moisture availability.

Table. Increase in yield (t/ha grain unit) of cultivated crops depending on the effect and aftereffect of manure[10]Yagodin B.A., Zhukov Yu.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

Effects on the first crop
Amount for 3 years
on the second crop
on the third crop
Non-Black Earth
Black Earth

The duration of after effect within each soil and climatic zone depends on the granulometric composition of the soil. For example, on clay soils, manure decomposes slowly, so the effect on the crop lasts up to 7 years, sometimes up to 16 years. On sandy soils, due to rapid decomposition, the effect on the crop lasts 3-4 years, on light and medium loamy soils – 6-8 years.

On sod-podzolic and gray forest soils, 1.5 times the after-effect in crop rotation without tilled crops and with tilled crops – 3 times exceeds the direct effect on the first (non-row) crop. With the saturation of the crop rotation with row crops, the effect increases. This pattern persists even with increasing doses of manure.

On black soils the effect is 4-5 times higher than the direct effect on the first non-row crop. When manure is applied to row crops as well as under favorable weather conditions the direct effect sharply increases. When crop rotation is saturated with cereal crops, the after-effect decreases, while when saturating with highly productive row crops it increases. This is explained by the fact that row crops more effectively use the direct effect and after-effect of manure.

Table. Effect of manure and equivalent amounts of mineral fertilizers on the productivity of crop rotations (t/ha grain unit) on different soils (according to the All-Russian Institute of Fertilizers and Agrochemistry)

Number of rotations of crop rotation
Yield of the control
Yield increase
Difference (more +, less -)
by manure
by mineral mixes
by manure
Sod-podzolic sandy and light loam
Sod-podzolic sandy and light loam, limed
Heavy and medium loamy sod-podzolic
Black earths
Soils with a high state of cultivation (according to foreign data)

The advantage of manure on light soils is also preserved on calcareous sod-podzolic varieties. On soils provided with organic matter positive effect of organic matter of manure is not observed, but the advantage of mineral fertilizers does not exceed 5-10%.

Aftereffect of manure is also explained by the improvement of physical, chemical, physical and biological properties of the soil. The aftereffect depends on the quality of the manure. Weakly decomposed straw manure in the first year may have a weak effect, later in the second and third years can provide a higher increase in yield.

The duration of effect is also determined by soil and climatic conditions. For example, in the northern areas the direct effect is greater, in the southern areas – the after-effect. In southeastern arid zone the after action exceeds the action in the first year. Peculiarities of manure application in southern and arid regions are related to the fact that manure decomposes slowly due to the lack of moisture and is low effective in the first year.

The highest effect is noted under all crops and on all soils when combining organic fertilizers with mineral. Even in half doses of joint application always provides an increase in yields is higher than the separate application of double doses of fertilizers. However, in practice, due to the lack of organic fertilizers have to make manure for one or two crops of the rotation, for subsequent – taking into account the after effects to add only mineral fertilizers.


Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.

Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. – M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, 2017. – 854 с.

Fundamentals of Agronomy: Tutorial/Y.V. Evtefeev, G.M. Kazantsev. – M.: FORUM, 2013. – 368 p.: ill.

Organic fertilizers

Organic fertilizers are organic matter resulting from the decomposition of plant, animal, plant-animal residues and industrial and domestic waste. Quantitative and qualitative composition of organic fertilizers depend on the origin, conditions of accumulation and storage. As a rule, contain a lot of moisture and various nutrients, but in small quantities, so they are referred to complete fertilizers. Usually poorly transportable, used at (or near) the place of receipt, so they belong to the local fertilizers.

Importance of organic fertilizers

The use of local organic fertilizers is a major human influence on the nutrient cycle in agriculture. Some organic fertilizers, such as manure, poultry manure, feces, green fertilizers, are a reuse of some of the previously taken from the soil and fertilizer nutrients, including additional fixed atmospheric nitrogen by nitrogen-fixing bacteria. The more fully the possible resources of organic fertilizers are used, the less the need for additional fertilizer purchases. Other organic fertilizers, such as peat, municipal waste, sapropels, as well as mineral fertilizers, serve as an additional source of nutrients in the cycle in any agrocenosis.

All organic fertilizers when mineralized are an additional source of carbon dioxide for plants, i.e. improve not only the root but also the air nutrition of plants.

Organic fertilizers are a source of energy and food for soil microorganisms, and many of them themselves are rich in microflora. Organic fertilizers are the most important factor in regulating soil fertility: the content of organic matter, labile forms of nitrogen, phosphorus, potassium, calcium, aluminum, iron, manganese, trace elements, acidity, capacity of cation exchange, the degree of saturation of the bases, biological activity, water and air regimes.

Organic fertilizers include:

  • manure;
  • manure without litter;
  • slurry;
  • poultry manure;
  • peat;
  • straw;
  • sapropel;
  • industrial and municipal wastes;
  • sewage sludge;
  • composts;
  • green fertilizers (siderates);
  • vermicomposts (biohumus);
  • humates.

The effect of organic fertilizers on crop yields affects for several years.

Under the conditions of intensification of agriculture reproduction of soil fertility, creation of positive or deficit-free balance of nutrients and humus are the most important problems of agriculture, which are solved by systematic scientifically based application of organic and mineral fertilizers in crop rotation.

Global experience of farming shows that the high culture of agriculture is associated with the accumulation, proper storage and use of organic fertilizers.

Effectiveness of organic fertilizers

All organic fertilizers are characterized by long-term action, so in determining the agronomic and economic efficiency sum reliable yield increases for all years, at least 3-4 years. The cost of preparation, purchase, storage, transportation, loading and unloading, harvesting and finishing should be distributed in proportion to the resulting increase in yields for all crops that received these increases.

Economic efficiency of organic fertilizers depends on the range of their transportation, for diluted with water (semi-liquid, liquid manure, slurry and sewage) on dilution: the further the transportation and more dilution, the less profitable and sometimes unprofitable this technology. Even when transporting by pipeline or using manure for fertilizer irrigation, the fertilizer is diluted with water at direct application: in the mixing chamber and pipeline transport stream.

Diluting manure to, e.g. during hydraulic flushing, and during storage requires the construction of storage ponds with good waterproofing. Therefore, it is economically feasible on farms and complexes to receive and store manure rather than manure effluent.

Economic efficiency of organic fertilizers also depends on the market conditions for agricultural products.

Maximum consideration of all economic factors allows the most reasonable to determine all available resources of organic fertilizers for crop rotations and off-farm plots, and within them – taking into account the action and aftereffects under the most profitable in agronomic, economic and environmental aspects of the crops.

The rate and degree of decomposition of organic fertilizers depend on the enrichment of soils with microorganisms, their composition and biological activity, as well as the conditions determining their vital activity: soil structure and aeration, water, thermal, nutrient regimes, physical and chemical properties.

Intensity of mineralization of organic fertilizers is determined by their biogenicity. Thus, manure – a biologically active substance, is rich in microorganisms, one ton of it contains up to 13 kg of living microbes. Peat, on the contrary, is poor in microorganisms and therefore slowly decomposes in the soil. Therefore, to speed up the decomposition process, biologically active substances are added, such as manure, slurry, feces, i.e. organic composts are prepared.


Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.

Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. – M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, 2017. – 854 с.

Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.

Liquid complex fertilizers (LCF)

Compared to solid fertilizers, the advantages of complex liquid fertilizers are ease of production, lower capital and operating costs. The ratio of nutrients in LCFs can be adjusted over a wide range. In contrast to liquid nitrogen fertilizers, LCFs do not contain free ammonia.

The tests showed the equivalence of solid and liquid complex fertilizers. A slightly higher efficiency of LCF was noted on carbonate and soils saturated with bases.

LPFs are one of the promising types of fertilizers. Fertilizer production scheme is to neutralize phosphoric acid with ammonia to pH 6.5. There are two types of LCFs with different types of acid: orthophosphoric and superphosphoric.

Ammonium nitrate, urea or a mixture of both are used as a nitrogen source for LCFs. Urea allows you to get a more concentrated fertilizer, especially in the presence of potassium in the solution, as formed by adding ammonium nitrate in a solution of potassium nitrate – the least soluble salt in liquid fertilizers.

Liquid fertilizers based on thermal orthophosphoric acid are almost transparent liquids, based on extraction orthophosphoric acid – cloudy solutions (due to the formation of aluminum and iron phosphates, silicic acid). Concentration of nitrogen-phosphoric LCF on the basis of superphosphoric acid is higher than on the basis of orthophosphoric acid.

Using thermal orthophosphoric acid produces LCFs with a nutrient ratio of 9:9:9, a total of 27% N, P2O5 and K2O. Crystallization of the solution does not increase the nutrient content. The typical composition of the 9:9:9 grade is as follows: (NH4)2HPO4 12-15%, NH4P2O4 2-4%, (NH2)2CO 12-13%, KCl 13-14%. Amide nitrogen is 61-66% of the total. These fertilizers can also be obtained from extractable phosphoric acid. Because of the low nutrient content, it is economically viable to use them locally. A good economic effect of LCF gives their application with irrigation water, including in orchards, berry fields, vineyards.

Table. Ratio of the main nutritional elements in liquid fertilizers produced on the basis of orthophosphoric and superphosphoric acid[1]Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al; ed. by V.G. Mineev. - M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, … Continue reading

Orthophosphoric acid
Superphosphoric acid

When polyphosphoric acid is used due to the high solubility of ammonium polyphosphates, basic solutions and balanced fertilizers with higher concentrations are obtained. Micronutrients that are chelated by polyphosphoric acid can be introduced into LCF on polyphosphoric acid, preserving their availability to plants, while the orthophosphates of trace elements, except for boron, form insoluble compounds. Micronutrients are introduced in the form of oxides, as this ensures high solubility and stability of solutions. Trace elements are introduced into basic solutions (8:24:0; 10:34:0; 11:37:0) at a temperature of 50-90°. Basic solutions obtained from polyphosphoric acid can be applied directly as a fertilizer or used for further mixing with nitrogen and potassium components.

Potassium chloride is a source of potassium for LCFs. Because of its insufficient solubility, it reduces the concentration of the liquid fertilizer. Potassium nitrate is less soluble and is formed when ammonium nitrate or urea-ammonium nitrate mixture is used as an additional nitrogen component. Urea slightly increases the overall solubility of the system.

In the USA, potassium fertilizer is applied separately in the fall or is added to the LCF at the expense of suspensions. Therefore, LCF of composition 10:34:0 is better to use on soils with sufficient available potassium. In this case, potassium fertilizers in the rotation is made once every 2 years under potassium-dependent crops.

The introduction of stabilizing additives in the solution, such as colloidal clay or silicic acid, protects the supersaturated solution from crystallization. Preparation of 1 ton of fertilizer requires 9-22 kg of dry clay. Recommended for use 28% suspension of clay in pure form, which is introduced first with a solution of 10:34:0, then a mixture of urea ammonium nitrate, in the last turn – potassium chloride. Red flotation potassium chloride with a particle size of 0.8-1 mm is suitable for suspensions. The sum of nutrients in suspended LCFs reaches 40-45%. Attapulgite or bentonite clays (1.0-1.5%) are used as stabilizing additives of suspended LCF.

Liquid propellant compounds are produced by methods of hot and cold mixing. When hot mixing at a temperature of 210-250 ° C neutralize phosphoric or polyphosphoric acid with ammonia, carried out at large plants, while receiving the basic (basic) solutions of ortho-and polyphosphate ammonium. The method of cold mixing at a temperature of 35-45 ° C is used in small plants near the areas of application, while producing fertilizers with a given ratio of nutrients by introducing urea, ammonium nitrate, potassium salts into the basic solutions.

Liquid complex fertilizers do not contain free ammonia, so they can be sprinkled on the surface of the field with subsequent embedding, and transportation is not necessary in hermetically sealed containers.

Liquid complex fertilizers are non-flammable, non-explosive and non-poisonous.

LCFs are applied by special machines locally, in bands, under any crops. They are used on irrigated lands and with irrigation water.

For application of suspensions a special complex of machines is required which differs from mechanized means for application of conventional liquid complex fertilizers. The Russian industry produces LCF of grades 8:24:0 and 10:34:0, the production of more concentrated solution – 11:37:0 is mastered.

Table. Characteristics of some of the properties of the LCF[2]Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al; ed. by V.G. Mineev. - M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, … Continue reading

Fertilizer grade
Sum of nutrients, %
Specific weight, g/cm3
Amount of nutrients, kg/m3
12:12:12 (суспензия)

The use of liquid complex fertilizers allows to mechanize loading and unloading processes, eliminate losses during transportation, storage and application to the soil. This eliminates manual labor and reduces costs.

The advantages of liquid complex fertilizers are also: automated control of fertilizer distribution in the field, the possibility of joint application of herbicides, insecticides, trace elements.

The economic effect is associated with a reduction in capital costs due to the elimination of some stages of the production process, such as drying and granulation. Capital expenditures for the construction of LCF production shops are 20-30% less than for solid fertilizers. Even with the equal cost of LCF, labor costs for their use are 3-3.5 times less. Transportation and application of LCFs is 2-2.5 times cheaper than solid fertilizers.

The introduction of liquid complex fertilizers requires the creation of special machines. It should be taken into account that these fertilizers (especially suspended) are corrosive.

Liquid complex fertilizers interact with the soil more fully than granular fertilizers. The rate of interaction determines the nature of the resulting compounds, their solubility and availability to plants.

Peculiarities of application and efficiency of liquid complex fertilizers

Peculiarities of liquid complex fertilizers application:

  1. When using LCF on the basis of orthophosphoric acid on acidic, phosphorus-fixing soil, such as red soil, with low phosphorus content, as well as on poor acidic sod-podzolic soils the effect of LCF is weaker than granular forms. This is noted when applying full LCF with a ratio of 1:1:1 and an additional nitrogen component (ammonium nitrate). When applying unbalanced solution with a ratio of N:P2O5 1:4,5 or 1:3, the reduction of phosphate component action on acidic sod-podzolic soil is not noted.
  2. On calcareous sod-podzolic soils and chernozems LCF and granular fertilizers are of equal value.
  3. On carbonate soils with an alkaline reaction, such as carbonate chernozems, chestnut soils, gray soils, the agrochemical value of liquid forms, more often than granular.
  4. On acidic sod-podzol soils, a short-term decrease in mobile phosphorus content is observed when the solution is applied, which is associated with phosphate fixation by halved oxides. This is not observed on chernozems.
  5. On gray soils after the application of LCF the amount of mobile phosphorus increases compared with the application of granular fertilizer.
    The effectiveness of LCF is determined by its constituent phosphorus and nitrogen components. For example, LPF with ammonium nitrate on acidic sod-podzolic soil and red soil is less effective than solid granular fertilizer, on urea – equally effective. On typical chernozem with weakly acidic reaction and gray soils, the form of the nitrogen component does not affect the effect of the fertilizer: the effectiveness of solutions and granular fertilizer is equal. Solutions are a better source of phosphorus for plants than granular forms. The presence of urea in the fertilizer positively affects the accumulation of mobile phosphorus in acidic soils and has no significance in chernozem and gray soils, which is due to the temporary alkalization of the environment during the transformation of urea.

The effect of liquid complex fertilizers on the quality of products (grain, potatoes, hay) is also equivalent to solid fertilizers.

The action of suspended fertilizers coincides with the action of LCF and depends on the properties of the nitrogen and phosphorus components. The suspended agent does not affect the efficiency of liquid fertilizers.

In liquid complex fertilizers based on polyphosphoric acid, half of the phosphorus is in the form of polyphosphate. The effectiveness of such fertilizers is determined by the presence of orthophosphate, the rate of hydrolysis of polyphosphate into orthophosphate and the properties of the compounds that are formed when applied to soil. Regularities of the action of polyphosphate LCF – 10:34:0 and 11:37:0 solutions with 45-65% phosphorus content:

  1. On sod-podzolic soils liquid ammonium polyphosphates create the same phosphate regime as orthophosphates, have the same effect on the yield, both in direct action and after action. Soil liming has no effect on this pattern. On strongly acidic, phosphorus-poor red soils the effect of liquid polyphosphates is slightly worse than that of granulated orthophosphates.
  2. On typical and leached chernozems the effect of liquid polyphosphates on grain crops is equal to that of liquid and granular orthophosphates.
  3. On carbonate chernozems polyphosphate LCF show a better effect on crop yields compared with granular fertilizers. This is explained by the fact that the application of polyphosphate in the soil for a longer time is stored more available orthophosphate, formed a reserve of soluble phosphate than the background orthophosphate fertilizers. On carbonate soils polyphosphates contribute to the supply of zinc to plants.
  4. On sulfur soils liquid ammonium polyphosphates are assimilated better than orthophosphates. The effect on the yield is equal to orthophosphates or exceeds them. Subsequently, polyphosphates are a better source of phosphorus than orthophosphates.
  5. Polyphosphates enriched with trace elements are effective.


Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.

Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. – M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, 2017. – 854 с.

Mixed fertilizers

Mixed fertilizers – complex fertilizers, obtained by mechanical mixing of fertilizers, contain several nutrients. They are used when it is necessary to apply several nutrients at the same time.

Dry mixing of fertilizers is an available, simple and economical method of obtaining complex fertilizers.

In terms of their agrochemical qualities are practically the same as complicated fertilizers. The advantage is the ability to produce a wide range of fertilizers with any ratios of nutrients that meet the requirements of agriculture. For example, in Western European countries the range of mixed fertilizers includes about 100 brands.

Mixtures of fertilizers can be easily adjusted to the requirements of crops, soil and climatic conditions both in terms of concentration and ratio of nutrients. This distinguishes them from complex fertilizers with a constant composition.

Depending on the type of mixed fertilizers the content of nutrients can vary from 25-30%, as with simple superphosphate, ammonium sulfate or ammonium nitrate, to 40% or more in mixtures based on concentrated fertilizers.

Mixed fertilizer production

In Russia, the current methods of obtaining dry mixed fertilizers are:

  • mixing directly in farms using stationary or mobile fertilizer mixing plants;
  • the use of stationary high-capacity units (40-60 t/h) to meet the needs of several farms;
  • mixing of fertilizers at chemical plants.

Domestic and foreign practice shows the prospects of creating agrochemical centers in districts and chemicalization points in farms. Equipped with warehouses and modern equipment for preparation, mixing and application of fertilizers and chemical means chemicalization points allow to carry out a complex of agrochemical works with qualified control over the receipt and use of fertilizers.

The advantage of this approach is to obtain fertilizers with high quality, good physical and mechanical and physical-chemical properties. To obtain homogeneous mixtures and reduce segregation (stratification) when applying to the soil, it is necessary that granular fertilizers have a homogeneous granulometric composition for all forms.

In the process of preparation and storage components of mixtures may be reactive, entering into chemical interaction with each other. The quality of mixtures obtained, their chemical composition and physical properties depend on the chemical processes that take place when mixing fertilizers. Therefore, it is important to choose the right components. Basic rules for mixing fertilizers:

  1. Do not mix fertilizers if it is possible to lose nutrients or their transformation into a poor in physical properties mass, not amenable to mechanized application.
  2. Due to the high hygroscopic nature of the mixture, ammonium nitrate and urea must not be mixed.
  3. Do not mix ammonia forms of nitrogen fertilizers, including complex fertilizers, with fertilizers with an alkaline reaction (phosphate slag, thermophosphate, calcium cyanamide, cement dust, potash) to avoid loss of nitrogen in the form of ammonia.
  4. Moisture content should not exceed permissible value. Higher moisture content reduces flowability and does not ensure uniform application. Acceptable moisture content in ammonium nitrate – no more than 0,2-0,3%, in urea – no more than 0,2-0,25% (0,12%[1]Yagodin BA, Zhukov JP, Kobzarenko VI Agrochemistry / Edited by BA Yagodin. – Moscow: Kolos, 2002. – 584 p.: ill.), ammophos, diammophos, and potassium chloride no more than 1 percent, in superphosphates (simple and double) no more than 3.5 percent (with free acidity not more than 1 percent). If the moisture content is increased, granules lose their strength. For ammonium nitrate this condition is noted at moisture content of 1.7-2.0%, urea – 1%, potassium chloride – over 3%. Moisture content in fertilizers increases with increasing storage temperature. Thus, a mixture of urea with double superphosphate and potassium chloride at initial moisture content of 0.2% after a month of storage at 4 ° C contained 6.6% moisture, at 20 ° C – 8.3%, at 40 °C – 24.9%.
Fertilizer mixing scheme
Fertilizer mixing scheme
  1. The number of granules 1-3 mm in size must be at least 90%, including a diameter of 2-3 mm – at least 50%, particles less than 1 mm – no more than 1%. Destruction of granules during mixing should be not more than 3%, strength – not less than 2 MPa (20 kg/cm2).
  2. The acidity or alkalinity of mineral fertilizers must comply with technical specifications. Fertilizers containing free acid or having an alkaline reaction, chemically interact with each other, and when mixed with other fertilizers. The content of free phosphoric acid in simple granulated superphosphate – no more than 2.5%, in double – no more than 5%. Mixtures based on double superphosphate are wetter than those based on simple superphosphate. The negative effect of excess acidity of double superphosphate is manifested when mixtures are stored in conditions of high humidity. Therefore, double superphosphate is an undesirable component of mixtures, and mixtures based on it are not prepared in advance.

Full neutralization of superphosphate or reducing the free acid content to 1% and moisture content to 4% in a simple one and to 3% in a double one, allows to mix it with urea and potassium chloride, receiving fertilizer of 1:1:1 composition. Mixtures of granulated ammophos with potassium chloride, neutralized superphosphates and ammonium sulfate have good physical properties, low hygroscopicity which provides the possibility of long-term storage.

  1. When neutralizing materials are added, such as limestone, dolomite flour, ammonia losses are noted.
  2. Mixtures of good quality are obtained on the basis of phosphate meal. The effectiveness of mixtures on the basis of superphosphate and phosphate flour in a ratio of 1:1, made in the occupied fallow or under plowing on acidic sod-podzolic soils and leached chernozems are not inferior to mixtures on pure superphosphate. For acidic soils, mixtures of potash fertilizer with phosphate meal are used. A mixture of ammonium nitrate and phosphate flour can be prepared and made under autumn plowing. It does not caked, stored for a long time. The presence of NH4NO3 and KCl increases the solubility of P2O5 phosphate meal. Adding 10% of ammonium nitrate and urea mixture to phosphate flour due to increased hygroscopicity reduces the dispersibility of phosphate flour while maintaining the stability of the seeding apparatus of the spreader.
  3. Superphosphate, especially in powder form, should not be mixed with ammonium nitrate, as the mixture turns into a sticky mass due to the formation of hygroscopic calcium nitrate:

Ca(H2PO4)2 + 2NH4NO3 = Ca(NO3)2 + 2NH4H2PO4.

Free phosphoric acid of superphosphate, interacting with ammonium nitrate, leads to the formation of nitric acid, which, decomposed or evaporating, leads to a loss of nitrogen:

Н3РО4 + NH4NO3 = HNO3 + NH4H2PO4;

4HNO3 = 4NO2 + 2H2O +O2;

Therefore, the mixing of these fertilizers should be done right on the day of application.

  1. Mixing superphosphate with urea leads to the release of crystallization water, which increases the moisture content of mixtures. For example, 12.2 to 64.7 g of crystallization water per 1 kg of mixture was released from the interaction of the components of mixtures from standard N, P, and K forms, whereas 7.2 to 13.5 g per 1 kg of mixture was released when dried products were mixed.
  2. The mixture of superphosphate and ammonium sulfate is cemented into a dense mass, which must be crushed and sifted before application. During mixing, the mass is heated and made wet by the release of water:

Са(Н2РO4)2⋅Н2О + (NH4)2SO4 → 2NH4H2PO4 + CaSO4 + H2O,

then the gypsum is formed:

CaSO4 + 2H2O = CaSO4⋅2Н2O.

To obtain good quality mixtures it is desirable to use neutral forms of phosphate fertilizers (ammophos, ammoniated superphosphate), which allow to obtain dry and loose mixtures with stable physical properties. Ammophos, moreover, provides a high concentration of nutrients: more than 50% of NPK instead of 28-31% in superphosphate, which saves transportation costs, warehouse construction costs, reduces the cost of loading, unloading and application of fertilizers. Of potash fertilizers the main component for mixing is potassium chloride, but for chlorophobic crops (potatoes, tobacco, grapes, citrus) it is better to replace it with chloride-free, such as potassium sulfate.

The quality of fertilizer mixtures is determined by the ratio of nutrients. Mixtures with a predominance of phosphorus and potassium over nitrogen are more likely to be drier and drier than mixtures of similar composition with an equal ratio of nutrients or with a predominance of nitrogen.

Due to increased production and use of urea, its use as a nitrogen component is being investigated. Mixtures with urea are moistened during storage due to the release of crystallization water. Stability of physical properties of such mixtures is increased by introduction of alkaline additive in an amount not less than 15 % of mixture weight. Urea is highly reactive, especially with potassium chloride. When it is included in the mixture moisture content increases sharply. To reduce the hygroscopicity of mixtures based on urea it is not recommended to include chlorides, as formed by the chemical interaction of CaCl2 and NH4Cl, are hygroscopic and accompanied by nitrogen loss.

In the mixtures, granules of 2-3 mm in size are more evenly distributed and particles less than 1 or more than 3 mm are unevenly distributed. Mixtures consisting of grains of different sizes and densities are subject to segregation, become heterogeneous during storage, transportation, mechanical incorporation into the soil.

Requirements for physical and chemical properties of the mixture depend on the amount of mixing, timing and methods of preparation, the scheme of transportation of fertilizers to the field. Physical properties of mixed fertilizers can be improved by introducing additives: chalk, limestone, phosphate meal.

Mixed fertilizers are produced for application immediately after mixing and in advance with subsequent storage.

Used for dry mixing one-sided and unbalanced composition fertilizers must retain loose and granulometric composition during transportation and storage in bulk for 6 months. The use of several components with improved physical and chemical properties allows to prepare mixed fertilizers, suitable for long-term storage. For example, the introduction of neutralizing additives and ammoniated superphosphate eliminates the release of nitric acid, the conversion of monocalcium phosphate in dicalcium phosphate, while improving the physical properties of the fertilizer.

When preparing mixtures you can quickly change the dosage of components depending on the crop, the fertility of the particular site, the form of fertilizer, etc. Therefore, the use of mixed fertilizers is a reserve for increasing their effectiveness. Increasing the volume of mixtures preparation is associated with higher requirements for the quality of fertilizers, granulometric composition and strength of granules, the availability of storage sites, a set of machines to mechanize technological processes. Mechanized preparation and application of the economic effect compared with the separate application of one-sided fertilizers.

Currently, the share of mixed fertilizers produced at chemical plants is increasing. This combines the mixing of fertilizers with their additional chemical treatment, the introduction of acids and neutralizing additives, more advanced granulation technology. The list of such fertilizers includes:

  1. Granulated complex mixed fertilizers obtained by ammonization of a mixture of simple superphosphate, potassium chloride and ammonium nitrate with the addition, if necessary, of sulfuric and phosphoric acids.
  2. Complex mixed fertilizers, enriched with or without trace elements, obtained by ammonization of a mixture of simple superphosphate, potassium chloride and ammonium nitrate.
  3. Pressed phosphate-potassium fertilizers, produced on the basis of a mixture of simple superphosphate and potassium chloride.
  4. Nutrient mixtures of 9-9-9 grade, enriched with microelements, on the basis of superphosphate, potassium magnesia, ammonium sulfate; with 22 to 56% of nutrients on the basis of superphosphate, urea, ammonium nitrate, potassium chloride or sulfate, limestone, dolomite, and fertilizer mixture of 12-12-12 grade are produced for retail sale.


Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.

Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. – M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, 2017. – 854 с.

Complicated fertilizers

Complicated fertilizers – mineral salts containing several plant nutrition elements, such as potassium nitrate (KNO3), ammonium hydrophosphate ((NH4)2NPO4). As a rule, they do not contain impurities (ballast), so they have a high content of nutrients.

Complicated fertilizers have advantages:

  1. High concentration of nutrients, no or little impurities such as sodium, chlorine.
  2. Fertilizer storage, transportation and application costs are lower. Often these costs are higher than fertilizer preparation costs. According to calculations, the costs for shipping, storage and application of complicated fertilizers compared to simple fertilizers are 10% lower.
  3. Due to the presence of several nutrients in a single granule of solid complex fertilizer allows for a more uniform distribution of nutrients on the soil surface.
  4. The absence of impurities allows you to apply in conditions where high concentrations of salts is undesirable, such as arid conditions, or when fertilizing crops that are sensitive to high osmotic pressure of the soil solution (flax, cucumbers).
  5. Higher fertilizer efficiency due to the presence of nitrogen, phosphorus and potassium in common foci.

Complicated fertilizer production

Production of complicated fertilizers in the USSR was started in the 60’s. Their share in total supplies to agriculture in 1980 was 20.2%. 

Ammophos dominates in the range of complicated fertilizers in Russia. Of the three-component fertilizers with a ratio of nutrients 1:1:1, nitrophoska and nitroammophoska are mainly used, of the two-component – nitrophos and nitroammophos. Later in the range appeared azophoska, diammonium phosphate, liquid complex fertilizers, diammophoska, ammophosphate, crystalline. In different regions the efficiency of carbamomophoska and carboammophos application was studied.

It is promising to expand the range of concentrated solid and liquid complex fertilizers through the use of polyphosphoric acids, as well as enriching them with trace elements, magnesium, etc.

An important property of complicated fertilizers is the solubility of their constituent components in water and solutions.

Technological methods of producing complicated fertilizers can be divided into two groups:

  • production on the basis of nitric acid decomposition of phosphate raw materials – nitrophos, nitrophosky;
  • production with the use of phosphoric acids – nitroammophos, nitroammophoski, diammonitrophoski, diammophoski, carboammophoski, ammophoski.

Complicated fertilisers were originally based on nitric acid decomposition of phosphate raw materials. Currently, phosphoric acid processes are used. Ammonium nitrate, urea and ammonium sulphate are used as nitrogen components.

Phosphoric acid derived from apatite and phosphate rock, as well as phosphate-containing products are used as phosphoric components. High-grade phosphate raw materials with high phosphorus content and small amounts of impurities, primarily oxides such as R2O3, are used for production. Phosphate ores usually contain a large amount of impurities, so almost all of them are subject to enrichment. Phosphate ores with a ratio of Fe2O3 : P2O5 more than 8-10, are not used for the production of water-soluble phosphate and complicated fertilizers.

Phosphate rock, with a high content of aluminum and iron oxides, little suitable for sulfuric acid processing for the production of phosphoric acid, as insoluble iron and aluminum phosphates are formed, and part of the phosphoric acid is lost. In practice, for the extraction phosphoric acid is used phosphate raw materials with a content of Fe2O3 not exceeding 8% of the mass of P2O5. The obtained wet-process phosphoric acid with a content of P2O5 28-32% for the production of complicated fertilizers is evaporated, increasing the concentration of P2O5 to 52%.

For the production of complicated fertilizers also use polyphosphoric (superphosphoric) acid acid containing 75-77% P2O5. Over half of the phosphorus in the acid is in polyphosphoric form (42% – in pyrophosphoric form H4P2O7, 8% – in tripolyphosphoric H5P3O10, 1% – in tetrapolyphosphoric H6P4O13), 49% of P2O5 – in orthophosphoric form.

Of the potassium-containing components for complicated fertilizers, mainly potassium chloride is used.

Complicated fertilizers based on nitrogen-acid decomposition of phosphate raw materials

The idea of decomposition of phosphate raw materials by nitric acid was first proposed in 1908. D.N. Pryanishnikov. However, it was realized much later when production of nitric acid from synthetic ammonia increased.

The process of decomposition of natural phosphate raw materials by nitric acid proceeds according to the reaction: 

Ca5(PO4)3F + 10HNO3 = ЗН3РО4 + 5Ca(NO3)2 + HF.

Released hydrogen fluoride interacts with silicon dioxide to form silicon fluoride, the latter reacts with hydrogen fluoride again to form silicic fluoric acid. From the decomposition of phosphate raw materials with nitric acid in the extract contains large amounts of calcium nitrate, which is an undesirable impurity in the finished fertilizer because of high hygroscopic properties and deterioration of the physical properties of complicated fertilizer.

The high calcium content of phosphoric acid leads to insoluble calcium phosphate, whose phosphorus is difficult for plants to access. Therefore, in the production of complicated fertilizers by nitric acid decomposition of phosphate raw materials, it is important to remove excess calcium from the system by reducing the CaO:P2O5 ratio. This production technology uses crushed apatite concentrate and 47-55% nitric acid. Technological schemes differ in the way of extraction of excess calcium from the solution.

Nitrophos and nitrophosks

Nitrophos and nitrophosks are produced by treating phosphate raw materials with nitric acid. The interaction produces calcium nitrate and calcium monophosphate with an admixture of dicalcium phosphate. The following methods are used to remove excess calcium:

1. Production of nitrophoska with freezing of excess calcium nitrate.

Partial freezing of calcium nitrate and its separation from the solution, followed by treatment with ammonia and simultaneous evaporation produces a mixture containing ammonium phosphate, dicalcium phosphate and ammonium nitrate:

H3PO4 + Ca(NO3)2 + NH3 = NH4H2PO4 + CaHPO4 + NH4NO3.

When potassium chloride or sulfuric acid is added to the mixture, nitrophoska is formed, including nitrogen, phosphorus, and potassium. The final products are nitrophoska and calcium nitrate.

Nitrophoska can contain up to 40-50% nutrients. The scheme has the ability to change the ratio of nutrients and receive granular fertilizer, in which up to 60% of P2O5 is water soluble. To obtain nitrofoska with 50-60% water-soluble phosphorus by this method, 70% of CaO is removed from solution in the form of Ca(NO3)2⋅4H2O. The fertilizer has shown high efficiency in all regions where plants are deficient in nitrogen, phosphorus and potassium.

2. Production of nitrophoska by binding excess calcium with carbon dioxide (carbonate scheme):

H3PO4 + Ca(NO3)2 + NH3 + CO2 = CaHPO4 + NH4NO3 + CaCО3.

When calcium nitrate and phosphoric acid are treated with ammonia and carbon dioxide, a mixture consisting of dicalcium phosphate, ammonium nitrate and calcium carbon dioxide is obtained. After mixing with potassium chloride, the mixture is pelleted, dried, separated into fractions and crushed without separating the calcium salts. Carbonate nitrophoska contains 35-37% nutrients. The scheme is the most economical in terms of production, but agrochemical production of carbonate nitrophoska in granular form is inexpedient because phosphorus is in it in citrate-soluble form. Powdered carbonate nitrophoska can be used for main application.

3. Production of nitrophoska and nitrophos by binding excess calcium with ammonium sulfate (sulfate scheme).

Ammonium sulfate is introduced into a hot mushy mixture of calcium nitrate and phosphoric acid (pulp), which reacts with calcium nitrate to form ammonium nitrate and anhydrous calcium sulfate. The mixture is dried and pelletized.

Depending on the consumption of ammonium sulphate you can get a product with different content of water-soluble P2O5.

To obtain a triple fertilizer, the necessary amount of potassium chloride is added to the hot pulp, which partially interacts with ammonium nitrate to form ammonium chloride and potassium nitrate:

KCl + NH4NO3 = NH4Cl + KNO3

After drying and granulation, sulphate nitrophoska is obtained. It is characterized by good physical properties and can be used for most crops on all types of soils. The mixture contains CaHPO4⋅2H2O, Ca(H2PO4)2⋅H2O, NaNO3, NH4Cl, KNO3, CaSO4.

If ammonium sulfate is replaced with potassium sulfate, the latter is dissolved in nitric acid and phosphate raw material is treated with this solution. The suspension is neutralized with ammonia, the product is pelletized and dried. Currently, this is the main way to produce nitrophoska with a 33-36% nutrient content.

4. Production of nitrophoska by binding excess calcium with sulfuric acid (sulfuric acid scheme).

Excess calcium is bound with sulfuric acid in the process of nitric acid decomposition of phosphates followed by treatment of the solution with ammonia. Potassium chloride is added to the resulting mixture to produce the finished product – sulfuric nitrophoska containing 35% of nutrients, the composition and properties are similar to sulfate nitrophoska. Bound excess calcium remains in the fertilizer as an impurity of calcium sulfate.

Ammonia may cause retrogradation of the formed soluble salts of phosphoric acid due to local alkalization of the medium.

The method allows to change the ratio of nutrients in a wide range and to produce a product containing up to 50-60% P2O5 in a water-soluble form.

5. Production of nitrophoska by binding excess calcium with phosphoric acid (phosphate scheme).

Phosphate raw materials are decomposed by a mixture of nitric and phosphoric acids in the ratio determined by the specified ratio of N:P2O5 in the finished product and the content of water-soluble phosphorus. The resulting solution after decomposition contains Ca(NO3)2 and free phosphoric and nitric acids. It is subjected to ammonization, in which the calcium of the solution is converted into dicalcium phosphate (CaНPO4). Calcium chloride is then added, granulated, and dried.

Under this scheme, the fertilizer with the highest content of water-soluble phosphoric acid (up to 80%) is obtained, in sulfate and sulfuric acid methods – about 55%. The introduction of potassium chloride produces phosphorus nitrophoska. The content of nitrogen, phosphorus and potassium is 17% each.

Several brands of granulated nitrophosks are produced in Russia.

Table. Characteristics of nitrophosphates

N, %
P2O5 (assimilable), %
Water-soluble P2O5 content, % (of total content)
Nitrophos grade A
Nitrophos grade B
Nitrophoska grade A (16:16:13)
Nitrophoska grade Б (13:10:13)
Nitrophoska grade В (12:12:12)

Nitrophosks granule size is 1-4 mm, quite strong, when conditioned by adding small amounts of mineral oil and powdering with talc or milled limestone, they do not cake during transportation and storage. Nitrophosks are used as a main fertilizer, pre-sowing in rows and in top dressing. The effectiveness is the same as equivalent amounts of mixtures of simple fertilizers.

Nitrophosks are used as the main fertilizer for many crops and for local application, especially for potatoes.

The production technology of nitrophosks, based on the decomposition of raw materials by nitric acid or its mixture with other acids, is used in foreign countries: Germany, Austria and France. In Germany, nitrophosks are produced without chlorides, some contain magnesium. France produces a large range of nitrophosks for various crops. Chlorine-free nitrophoska is produced for grapes and fruit crops.

In recent years, technological schemes for the production of nitrophosks with 80-95% P2O5 in water-soluble form have been developed, among which the Norwegian method is widespread. Phosphorite by this method is treated with excess nitric acid, followed by crystallization of calcium nitrate at a temperature of -50 °C. This method or its variants are used in Russia, England, Germany, France and the Netherlands. In France, a technology has been developed to produce 54 grades of nitrophosks with a ratio of nitrogen from 8 to 20%, P2O5 – from 7 to 35% and K2O – up to 29%.


Nitroammophos is a mixture of NH4H2PO4 + NH4NO3. It is produced by neutralizing mixtures of nitric and phosphoric acids with ammonia. The content of nitrogen and phosphorus is 23% of each. When potassium salts are added, nitroammonium phosphate is produced. The content of N, P2O5 and K2O is 16-17% each. They almost do not contain ballast. The amount of water-soluble phosphates is over 90%. Nitrofoski can be used by the same methods as nitrofoski. The efficiency is comparable to mixtures of simple fertilizers.

Nitroammophoska 17:17:17 is produced by the introduction of potassium chloride, and with the introduction of potassium sulfate – mark 16:16:16. The fertilizer is universal and is used on all types of soils as the main fertilizer, for sugar beets and potatoes – also at sowing.

Complicated fertilizers produced by neutralizing phosphoric acids with ammonia

Ammonium phosphates (ammophos and diammophos)

Н3РO4 + NH3 = NH4H2PO4 – monoammonium phosphate (ammophos),

H3PO4 + 2NH3 = (NH4)2HPO4 – diammonium phosphate (diammophos).

Ammophos contains 10-12% N and 46-50% P2O5. Diammophos, produced from apatite, contains 18% N and 50% P2O5, from Karatau phosphorites – 16-17% N and 41-42% P2O5. Ammophos is characterized by good physical, chemical and mechanical properties without the use of conditioning additives during granulation. Ammophos and diammophos are physiologically acidic fertilizers.

Ammophos is mainly used as a row fertilizer for crops and as the main fertilizer, for example, for cotton. It is a good component for the preparation of mixed fertilizers, as it is compatible with many fertilizers. The disadvantage is the unbalanced ratio of nitrogen to phosphorus (1:4), while the optimal ratio of nitrogen to phosphorus should be close to one or less (most plants consume nitrogen than phosphorus).

Diammophos has this ratio of nitrogen to phosphorus (1:2.5), but its physical properties are worse. It can also be used for row application and as a top dressing for technical and vegetable crops. Because of its high cost, its application is limited; it is used in livestock production as a feed additive. It is the most concentrated of all complicated fertilizers.

By adding potassium chloride to ammophos and diammophos, triple fertilizers are produced, which are common in the United States, England, Japan and India, because these countries have large reserves of sulfur and large production of sulfuric acid, which provides phosphoric acid and complicated fertilizers based on it. The United States leads the world in the production and use of mono- and diammonium phosphate. Because of the unbalanced nitrogen to phosphorus content in the U.S., a large volume of these fertilizers are used to make mixed fertilizers.

Comparative tests of these fertilizers with equalized K doses under major crops and on major soil types have shown their equal effectiveness to an equivalent mixture of simple fertilizers.

Ammonium phosphates are convenient for local application as a pre-sowing or pre-sowing fertilizer. They do not contain large amounts of ballast, do not create a high concentration of the solution and do not increase its osmotic pressure.

Ammonium polyphosphates

Until recently, the production technology for superphosphate, precipitate and ammonium phosphate was based on the use of orthophosphoric acid (H3PO4), which in pure form contains no more than 54% P2O5. Mixtures of polyphosphoric acids contain from 70 to 83% P2O5, which allows to obtain more concentrated complex fertilizers.

Preparation of polyphosphoric acids requires heating and vacuum:

2H3PO4 —(heating, vacuum)→ H4P2O7 + H2O;

H3PO4 + H4P2O7 —(heating, vacuum)→ H5P3O10 + H2O;

H5P3O10 —(heating, vacuum)→ 3HPO3 + H2O etc.

In these reactions, phosphate groups are condensed, which is why polyphosphoric acids are called condensed acids. In the chemical industry, they are also called superphosphoric acids, which is more of a commercial term.

Polyphosphoric acids: HPO3 – metaphosphoric, H4P2O7 – pyrophosphoric, H3P3O10 – tripolyphosphoric, H6P4O13 – polyphosphoric. In the USSR polyphosphates were produced in 1964.

For transportation of polyphosphoric acids they use special stainless steel truck and railroad tanks.

Initial product for production of polyphosphates is mixture of polyphosphoric acids, obtained from concentrated orthophosphoric acid or phosphorus. The most concentrated polyphosphoric acids are derived from thermal orthophosphoric acid.

Polyphosphoric acids are used to make triple superphosphate containing 55% P2O5. When polyphosphoric acids are saturated with ammonia under pressure, ammonium polyphosphates are produced.

Table. Characteristics of some ammonium polyphosphates[1]Yagodin B.A., Zhukov Yu.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

N, %
P2O5, %
N+P2O5, %
Diammonium pyrophosphate
Triammonium pyrophosphate
Tetraammonium pyrophosphate
Pentaammonium tripolyphosphate dihydrate

For practical purposes, the second and third of these ammonium polyphosphates are valuable, characterized by high phosphorus and nitrogen content and an acceptable ratio. These fertilizers are used in solid form or introduced as the main component in liquid and suspended fertilizers.

Ammonium polyphosphates are highly soluble in water. Ammonium polyphosphates can be partially replaced with potassium, calcium or trace elements (zinc, copper, iron). The latter with orthophosphates form insoluble salts, while with polyphosphates they are chelated and remain available for plants, which is promising for the creation of new types and forms of fertilizers.

The physical properties of ammonium polyphosphates are good, the granules are strong, are a good component for mixed fertilizers. Thus, by adding ammonium nitrate or urea and potassium chloride, you can get a triple fertilizer with a total content of the active substance of 60%.

In the USA, solid mixtures are prepared from polyphosphoric acid and solid ammonium polyphosphate with the addition of potassium salt, magnesium oxides, zinc, and molten sulfur. This makes it possible to produce fertilizers that are more complex in composition and intended use.

Polyphosphates in the soil are less mobile than orthophosphates, as more active interact with soil minerals. Hydrolysis of polyphosphates occurs in the soil, the intensity of which increases with increasing biological activity of the environment. At 7-12 °C, they are slow, with increasing temperature – increased. The optimal temperature for hydrolysis is 30-35 °C. Polyphosphate hydrolysis reactions:

HPO3 + H2O → Н4Р2О7;

Н4Р2О7 + H2O → 2Н3РО4;

H5P3O10 + 2H2O → 3Н3РО4.

Plant uptake of phosphorus by polyphosphates is slower than by orthophosphates, due to hydrolysis of the latter to the orthophosphorus form. During the growing season, the advantage in phosphorus uptake is retained by polyphosphates, since retrogradation is less pronounced than for orthophosphates. Ammonium polyphosphates are used for all crops on all types of soils.


Phosphoammonium-magnesia, or magnesiumammonium phosphate (MgNH4PO4⋅H2O) is a low-soluble complicated fertilizer containing 10.9% N, 45.7% P2O5 and 25.9% MgO. Nitrification of ammonium under soil conditions is as fast as that of ammonium fertilizers. Nitrogen is represented by water-soluble form, phosphorus and magnesium by citric-soluble form. Therefore, these fertilizers belong to the long-term fertilizers. It is advisable to use them on light sandy soils as the main fertilizer for potatoes, root crops and vegetable crops, as well as in irrigated agriculture, greenhouses when growing vegetables on hydroponics.

Magnesium-ammonium phosphate is formed by the interaction of a solution of monoammonium phosphate with an aqueous suspension of magnesium oxide or its salts or phosphoric acid, ammonia and magnesium hydroxide with its salts (chloride, sulfate or carbonate). For example:

MgCl2 + (NH4)2HPO4 + NH4OH → MgNH4PO4 + H2O + NH4CI.

Carboammophos and carboammophosks

Carboammophos is produced by the interaction of urea synthesis intermediates (ammonia and carbon dioxide) and phosphoric acid. The ratio of nitrogen and phosphorus is – 25:30; 34:17; 33:20, etc.

With the introduction of potassium-containing salts get carboamphoska with an aggregate content of nutrients up to 60-65%, for example, grade 20:20:20. Nitrogen in these fertilizers is in amide (70-75%) and ammonia forms, up to 90% of phosphorus – in a water-soluble form.

In field experiments, the use of these fertilizers is equal to mixtures of simple fertilizers. Rice and cotton plants are better affected than mixtures of simple fertilizers with ammonium nitrate. In hayfields and pastures, nitrogen losses were noted with surface application.

Potassium metaphosphate

Potassium metaphosphate (KPO3) contains up to 60% P2O5 and up to 40% K2O, a concentrated complicated fertilizer. Potassium metaphosphate with phosphorus content in citrate-soluble and water-soluble forms is obtained. The most promising method is the decomposition of potassium chloride or carbonic acid with orthophosphoric acid at a temperature of 450 °C. When using extraction phosphoric acid, potassium metaphosphates containing 54% P2O5 (in water-soluble form), 35-40% K2O, and 60% P2O5 (in citrate-soluble form) and 40% K2O are obtained.

In a number of experiments, potatoes, sugar beets, barley, flax showed a good effect from the use of this fertilizer.

Potassium nitrate

Potassium nitrate (KNO3), contains 13% nitrogen and 46% potassium oxide, contains no ballast impurities and has good physical properties. The formation of potassium nitrate is based on the exchange reaction of NaNO3 and KCl: 

NaNO3 + KCl → NaCl + KNO3.

Concentrated solutions of sodium nitrate, which are formed during the alkaline absorption of waste nitrous gases in the production of nitric acid, and potassium chloride are used as feedstock. The fertilizer is non-hygroscopic and well dispersed. It is applied to vegetable crops, especially indoors. Good for crops that are sensitive to chlorine.

A disadvantage of potassium nitrate is the ratio between nitrogen and potassium (1:3.5). Therefore, its application requires the additional application of nitrogen fertilizers, and if it is necessary to apply phosphorus, then phosphorus fertilizers.

Application and efficiency of complicated fertilizers

The effect of complicated fertilizers on crop yields depends on:

  1. presence of water-soluble forms of phosphorus in their composition;
  2. the type and biological characteristics of crops;
  3. soil and climatic conditions;
  4. agronomic technology of application (timing and methods of application);
  5. ratio of nutrients in the fertilizer;
  6. forms of nitrogen, phosphorus and potassium components of fertilizers;
  7. complex of agronomic practices, against which complicated fertilizers are used.

All factors are interrelated. Thus, on sod-podzolic soils citrate-soluble form of P2O5 under direct action and after action is also available for plants, as well as water-soluble, whereas on chernozems, gray soils and chestnut soils more accessible water-soluble form. In complicated granular fertilizers the optimum content of water-soluble P2O5 from assimilated should be at least 50%, on chernozems and gray soils – at least 60-70%.

Sulfuric acid nitrophoska, nitroammophoska and diammonitrophoska with the highest content of water-soluble phosphorus provide the maximum efficiency on sod-podzolic soils. The effect of carbonate granular nitrophosks, which contain almost no water-soluble phosphorus, worse than the equivalent mixtures of simple fertilizers, especially on chernozems. With an increase in the proportion of water-soluble phosphorus in the composition of the fertilizer the coefficient of its use by plants increases. The same pattern is maintained when evaluating the methods of fertilizer application. For example, complicated fertilizers with a high content of phosphorus in water-soluble form are more effective at local application.

Three-component complicated fertilizers in different soil and climatic conditions show high efficiency. In the zonal aspect, taking into account the biological characteristics of crops the following regularities compared with mixtures of simple fertilizers are noted:

  1. In forest-podzolic and forest-steppe zones on sod-podzolic soils and chernozems three- and two-component fertilizers in crops of cereals, sugar beet, flax and potatoes at basic application are equivalent to mixtures of one-sided fertilizers on efficiency, in some cases exceed them. Chlorine-free nitrophoska is more effective on potatoes.
  2. In the steppe zone on common, carbonate, southern chernozems the efficiency of complicated fertilizers is less than in the forest-log zone. In this zone, the yield increase of grain crops from applying nitroamphoska is higher than from nitrophoska.
  3. On chestnut soils and gray soils irrigation increases the efficiency of fertilizers. The effect of two- and three-component complicated fertilizers on cereal crops, corn and cotton is better than mixtures of simple fertilizers.
  4. Under conditions of rice cultivation as a flooded crop, the efficiency of complicated fertilizers containing nitrate nitrogen is lower than that of fertilizer mixtures containing ammonium or amide nitrogen.
  5. Complicated fertilizers are effective when applied pre-sowing to cereals, industrial, silage crops and annual grasses.

Local application of nitroammophoska on sod-podzolic, gray forest soils and chernozems is more effective than superphosphate. On the background of the main application and the increased content of phosphorus in the soil at row application the effect of mineral fertilizers is reduced. Biological characteristics of crops and diversity of soils determine the need for complicated fertilizers with different ratios of nitrogen, phosphorus and potassium.

On sod-podzolic soils, phosphorus and potassium fertilizers when applied in the fall and spring show about the same effectiveness. Spring nitrogen fertilizer application is more effective than the fall fertilizer, because nitrogen is washed into the underlying soil layers during the winter-spring period, which causes nitrogen starvation of winter and spring crops in the spring. Therefore, on loose sandy soils, complicated fertilizers and equivalent mixtures of simple fertilizers are ineffective when applied in a full dose from autumn. On winter crops, the effect of complicated fertilizers increases with half the dose of nitrogen applied in the spring.

Thus, on sod-podzolic soils, complicated fertilizers with a predominance of phosphorus and potassium in the autumn application for winter and spring crops and the introduction of nitrogen at a full dose in spring are more effective compared with a full dose of fertilizers in an equalized ratio of nutrients, made in autumn.

In the zone of sufficient moisture, especially on light sod-podzolic soils, it is recommended to apply a complicated fertilizer in autumn with less nitrogen (1:2:2, 1:2:1, 1:4:0), followed by the spring application of additional nitrogen to the optimum content. On leached chernozems and sod-podzolic clay soils single application of the whole dose of complex or mixtures of simple fertilizers is not inferior to fractional application during the growing season.

Complicated fertilizers based on urea for basic application to cereals, potatoes, sugar beet, corn and other crops on the soils of the forest and steppe zones are as effective as nitroamphoska and simple fertilizer mixtures. When fertilizing rice on meadow-chernozem soils carbamammofoska and fertilizer mixture with ammonium sulfate showed a greater positive effect on yield than nitroammofoska, because the latter contains nitrogen in nitrate-ammonium form.

In meadows and pastures on sod-podzolic and mountain-meadow soils carboamphoska and carboammophoska inferior in their effect to fertilizers with nitrate-ammonia form of nitrogen, which is associated with nitrogen losses as a result of urea hydrolysis at surface application. On cotton and cereal crops under irrigation conditions on chestnut soils and gray soils urea-containing fertilizers are more effective than mixtures based on ammonium nitrate.

As polyphosphates are just as effective as orthophosphate-based fertilizers, they can be applied to crops under various soil and climate conditions.

In powdered calcium polyphosphate phosphate phosphate is in a citrate-soluble form, which in some cases reduces its effect, for example, on potatoes, a crop that responds better to water-soluble phosphate fertilizers.

Adding micro-nutrients to macrofertilizers improves plant nutrition and increases their effectiveness. A range of complicated fertilizers enriched with micronutrients has been developed. For example, ammophos containing N – 12% and P2O5 – 51%, B – 0.4%, Zn – 1.0% Mn – 3.0%; nitroammophoska containing N – 17%, P2O5 – 17%, K2O – 17%, B – 0.17%, Mo – 0.05%, Mn – 1.5%, Co – 0.05% and I – 0.003%; carboammophoska – N – 21%, P2O5 – 21%, K2O – 21%, I – 0.2%.


Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.

Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. – M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, 2017. – 854 с.

Complex fertilizers

Classification of complex fertilizers

According to the number of components complex fertilizers are classified:

  • dual, for example, containing phosphorus-potassium, nitrogen-phosphorus, nitrogen-potassium;
  • triple, containing nitrogen, potassium and phosphorus.

According to the method of production:

  • complicated;
  • complex-mixed (combined);
  • mixed.

By aggregate state;

  • solid;
  • liquid.

Complicated fertilizers

Main article: Complicated fertilizers

Complicated fertilizers – mineral salts containing several plant nutrition elements, such as potassium nitrate (KNO3), ammonium hydrophosphate ((NH4)2NPO4). As a rule, they do not contain impurities (ballast), so they have a high content of nutrients.

Complex-mixed (combined) fertilizers

Complex-mixed (combined) fertilizers – complex fertilizers containing two or more nutritional elements, obtained in one technological process by interaction of nitric, phosphoric and sulfuric acids with ammonia, natural phosphates, potassium salts or ammonium. In terms of chemical composition they are a mixture of several mineral salts.

The main technological operations in the production of complex mixed fertilizers: mixing the initial components, ammonization of the mixture, granulation, drying and conditioning the product. As a result, you can get fertilizer grades with different ratios of nutrients. For example, on the basis of simple and double superphosphate, ammonium nitrate, ammonium sulfate, an ammoniating solution consisting of 21.7% ammonia and 65% ammonium nitrate, sulfuric acid can be obtained fertilizers of composition: 5:10:20; 5:20:20; 8:16:16; 8:24:0; 8:24:8; 8:24:16; 10:20:0; 10:20:12; 12:12:12; 5:10:10. Using a solution containing 26-30% urea, 14-24% ammonium nitrate, and 25-35% NH3, a 20:10:10; 15:15:15:15 fertilizer is made. On the basis of polyphosphoric acid using ammonia, sulfuric acid, simple and double superphosphate and potassium chloride, fertilizers are produced brands 6:24:24; 10:45:5; 8:32:16 and others with a water-soluble phosphate content of 65%.

Complex-mixed fertilizers include solurin and crystallin, containing nitrogen, phosphorus, potassium, magnesium, trace elements (Mn, Zn, Cu, Co, I, etc.). Fertilizer is soluble in water, it is used in greenhouses and in open ground. Solurin grades 10:5:20:6; 18:6:18:0; 19:6:6:6:0; 13:40:13:0; 17:17:6:0; 16:16:16:0; 20:16:20.

Mixed fertilizers

Main article: Mixed fertilizers

Mixed fertilizers – complex fertilizers, obtained by mechanical mixing of two or more simple fertilizers in granular or powder form.

Liquid complex fertilizers

Main article: Liquid complex fertilizers

Liquid and suspended complex fertilizers – complex fertilizers, obtained by mixing a solution of fertilizers. Sometimes gaseous and solid substances and suspending additives are added.

Application of complex fertilizers

The advantages of complex fertilizers are the high content of nutrients with simultaneous content of several elements. The production cost of complex fertilizers (in terms of nutrients per unit) is higher than that of simple fertilizers, but the cost of delivery, storage and application is much lower compared to simple fertilizers. The total cost of application of complex fertilizers, taking into account production costs, is about 10% lower than that of simple fertilizers.

The content of a single granule of several nutrients contributes to a more uniform distribution on the soil surface.

Complex fertilizers provide better positional availability of nutrients to the root system. According to experiments, when fed separately with nitrogen, phosphorus and potassium (when placing them in different parts of the vessel), corn developed worse, absorbing less phosphorus than when fed jointly with nitrogen and potassium.

The effectiveness of equal doses of complex and a mixture of unilateral fertilizers on the effect on the yield is the same.

Depending on crops, soils, climatic conditions require complex fertilizers with different ratios and contents of nitrogen, phosphorus and potassium. They are characterized by the mass ratio of N:P2O5 : K2O, for example, 1:1,5:0,5 (nitrogen is taken as one), or the percentage ratio of N : P2O5 : K2O for the content of active elements, for example, 12:18:6 or 12-18-6, the sum of the percentage gives the total content of active substances in fertilizer.

The most common are three-component fertilizer grades 1:1:1:1; 1:1.5:1; 1:1:1.5; 1:1.5:1.5; 1:1:0.5 and two-component grades 1:2.5:0; 1:4:0; 1:1:0; 0:1:1:1; 0:1:1.5.

The ratio between the components in the composition of fertilizers does not always correspond to the needs of crops when growing on soils with different security, so in such cases, in addition one-sided fertilizers or appropriate fertilizer mixtures are made.


Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.

Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. – M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, 2017. – 854 с.

Lithium fertilizers

Lithium is a biologically important element in plant life and influences the content and heterogeneous composition of proteins and nucleic acids, enzymatic activity of enzymes associated with protein-nucleic acid metabolism.

There is data on the role of lithium in the carbohydrate metabolism of plants, an increase in the intensity of photosynthesis during the reproductive period, an influence on the rate of photorespiration and grain productivity of winter wheat. Specific role in alkaloid metabolism is marked. Influence on ascorbic acid accumulation in plants and positive action in the fight against viral infections were established.

The necessity of lithium for humans and animals was proved. The effectiveness of lithium in various diseases depends on its effect on neuroreflex activity as well as adrenolytic, noradrenolytic, antihistamine, antiserotonin action and regulating effect on hormonal activity of endocrine glands, especially cortical layer of adrenal glands. In hypertension of different origin, lithium has anti-stress and sedative effect. Positive effect in some pathological processes is determined by a stimulating effect on the immune system and on nonspecific protective reactions of the body.

When lithium is in excess in human body, it has toxic effect. Symptoms of poisoning indicate a neurotoxic effect of lithium. Increased content in feed leads to decalcification of bone tissue and morphogenic changes in animals. Correction of human and animal intake with agricultural products enriched with lithium is promising.

At present, there is no information on the necessity of lithium for agricultural plants: the reaction to lithium fertilizer application depends on habitat conditions, age and systematic position. Positive effects of lithium fertilizers on tobacco, cotton, sugar beets, tomato, sweet peppers, and potatoes have been noted.

On the other hand, the use of lithium fertilizers as a microfertilizer requires taking into account its possible toxicity. An excess of lithium salts leads to morphological changes in plants – disruption of mitosis. Cypresses, crucifers, honeysuckles, lilies, irises, grasses are very sensitive to lithium.

The intake into plants depends on the content of mobile forms in the soil. Lithium content in soils increases from north to south – from 10-25 mg / kg for sod-podzolic soils to 65-90 mg / kg for ordinary chernozems. The amount of the element depends on the content of lithium in soil-forming rocks, granulometric composition (more lithium in heavy soils), on the amount of organic matter and degree of leaching. The concentration of exchangeable lithium decreases along the soil profile, and it is least mobile in the horizons with maximum accumulation of calcium carbonates. Soil salinization reduces mobility. In addition, there is a relationship between lithium and potassium content in the soil.

In plants, lithium content depends on the systematics and nutritional conditions. Among plants that concentrate in all conditions and prefer its high content in the soil – nightshade, violets, buttercups. Their lithium content is about 60 mg / kg of dry matter. Malvae and Marecae accumulate it only when it is high in the soil. Plants indifferent to lithium – long-leaf mint, camel’s-thorn – contain 20-45 mg/kg of dry matter. Legumes consume small amounts of 4.8-7.9 mg/kg dry matter, but do not avoid land enriched with it. Cereals and bentgrasses consume small amounts and avoid soils high in lithium.

The accumulation of lithium in plants is influenced by soil and climatic conditions. Distribution by plant organs has the following pattern: leaves > roots > stems > fruits. Therefore, leafy vegetables and root crops are the main source of lithium in the diet of animals and humans.

The application of lithium fertilizers for various crops gives mainly positive results, which depend on the method of application and doses. For this purpose, lithium chloride, sulfate and carbonate are used. For pre-sowing soaking (moistening) of potato seeds or tubers, lithium solutions of 0.001 to 0.05% are used, depending on culture. For foliar feeding – solutions from 0.005% for grapes and potatoes, to 0.1% for tobacco. In the soil apply in doses of 0.1-40.0 mg/kg soil, depending on the crop and salt.


Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.

Selenium-containing fertilizers

Selenium in plant life

Selenium is involved in reactions of chlorophyll formation, synthesis of tricarboxylic acids, in metabolism of long-chain fatty acids. The presence in plant cells of ferrodoxins containing selenium instead of sulfur indicates its participation in photosynthesis processes. It has an antagonistic effect on the absorption and transport of heavy metals, increases resistance to water stress, salt and drought tolerance. Excess and deficiency of selenium in nutrient medium has a negative effect on plant growth and development. An accumulation of free soluble amino acids and inhibition of protein synthesis are noted with selenium excess.

At present it does not belong to the microelements necessary for plants, but it is vitally important for warm-blooded animals. When deficiency occurs both specific trace element diseases and diseases of other etiologies. Selenium deficiency in humans leads to the development of cardiomyopathy – Keshan disease, cancer. Among the diseases of farm animals – white muscle dystrophy. Deficiency of selenium in food and drinking water – a pathogenic factor in necrotizing liver degeneration, lesions of the pancreas and intestines, exudative diathesis. Selenium helps protect the body from chemical mutagenesis initiated by toxic doses of heavy metals. With a deficit of selenium reduced immunity and mental development in children. The effect of selenium on iodine metabolism and thyroid activity was established.

The daily requirement of a person for selenium is 40-220 micrograms and depends on the phenotypic features of the organism, the form of incoming selenium, the content of proteins in food, vitamins C and E, to a lesser extent – on age and sex. The deficiency of selenium in food has a global nature: according to numerous studies, the majority of the population experiences a varying degree of selenium deficiency in the diet.

One promising way to correct selenium deficiency is to obtain plant products enriched with selenium. At the same time plants differ in their ability to accumulate selenium. In addition, selenium is unevenly distributed among plant organs. Thus, wheat stems and leaves contain about 2-3 times less selenium than grains and roots. In general, the concentration of selenium in plants varies from 10 to 1100 micrograms in 1 kg of air-dry weight.

Analysis of selenium content in plants of different families showed that the average content in most species is no more than 100 µg/kg.

Table. The content of selenium in plants of the Non-Chernozem zone, μg/kg dry weight[1]Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry / Ed. by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

Number of species
Weighted average

Maximum concentrations of selenium are in the legume, bluegrass, and aster families, while the lowest concentrations are in the celery family.

In countries where Keshan and Kashin-Beck diseases are common, such as China, foods are enriched with selenium. Another way is to import into a selenium-deficient region foods produced on soils with high selenium content. In Scandinavia, where soils, especially in the north, contain little selenium, selenium-containing fertilizers have been used for grain crops and forage grasses for the past 20 years.

Selenium content of soils

In the countries of Europe and Asia a large-scale mapping of selenium content in soils, waters, plants has been conducted, attempts are made to regulate selenium content in human foodstuffs and animal diets. In Russia extensive biogeochemical territories with varying degrees of selenium deficiency in the Nonchernozem zone, Southern Urals and Transbaikalia have been identified. Biogeochemical province with an excess of selenium is found in Uyug and Baryk valleys of Tuva.

Agroecological survey of the regions of the Non-Black Soil Zone of the European part of the country showed its low content – 61-729 µg/kg. The lowest amount up to 169 µg/kg is characteristic of podzolic and sod-podzolic soils, as well as soils on sandy soil-forming rocks. Maximum concentrations of selenium, from 521 to 727 µg/kg, were found in peaty, gleyed, iron oxide-enriched and carbonate-rock-formed soils. In most cases, soils contain up to 400 μg Se/kg soil, which refers to the deficit content.

There are complex interrelations of selenium in soils with other elements of mineral nutrition of plants. For example, the application of cobalt, zinc, nickel increases the microbiological formation of volatile selenium compounds, boron and manganese have no effect on these processes, molybdenum, mercury, chromium and lead inhibit the transformation of selenium compounds into volatile forms.

For several years in the laboratory of microelements of the Moscow Agricultural Academy of Sciences researches on cultivation of agricultural products enriched with selenium are carried out. In a series of experiments the effect of applied sodium biselenite on the yield, its quality and content in vegetable crops, wheat, rapeseed and lupine was studied.

The studied vegetable crops without selenium application accumulated in small amounts, 56-303 mg/kg dry weight. The application of sodium biselenite in increasing quantities from 25 to 500 micrograms of Se/kg of soil resulted in the increase of its content in dill plants by 2,5-15,7 times, in radish roots by 4 times, in parsley roots by 2,4-3,8 and in the above-ground part by 3,5-10,0 times. With the increase of sodium biselenite dose from 50 to 1000 μg Se/kg soil, its content in leaf lettuce increased by 10 times, in spring garlic by 3.7-16.0 times, in the green mass of yellow lupine by 3-11 times and in grain by 6-25 times. Foliar feeding of yellow lupine with 0.0005- and 0.002% sodium biselenite solution in field experiments increased the content in green mass by 4-9 times, in grain by 4-8 times.

Table. The content of selenium in some crops when fertilizing them with sodium biselenite[2]Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

Dose of Se, µg/kg soil
Light loamy soil
Heavy loamy soil
µg/kg dry weight
% of control
µg/kg dry weight
% of control
Dill, above ground part
0 (control)
Radish, root vegetables
0 (control)
Parsley, aboveground part
0 (control)
Parsley, roots
0 (control)
Lettuce, leaves
0 (control)
0 (control)

Thus, in experiments on sod-podzolic soils, the application of selenium in doses of 25-1000 µg/kg of soil allows for significant enrichment of agricultural products with selenium without reducing yields. Garlic turned out to be the most pronounced concentrator among the tested crops.

As selenium-containing fertilizers in world practice use selenites and selenites for foliar dressing and seed treatment. The most effective and applicable method is the application of selenium to the soil together with macrofertilizers.


Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.

Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. – M.: Publishing house of the All-Russian Scientific and Research Institute named after D.N. Pryanishnikov, 2017. – 854 с.

Cobalt fertilizer

Cobalt in plant life

The content of cobalt in plants is on average 0.00002%. Its amount can vary from 0.021 to 11.6 mg per 1 kg of dry weight. A large amount is contained in the nodules of leguminous crops. It is also concentrated in generative organs, accumulates in pollen, accelerates its germination. In plants, about 50% of cobalt is in ionic form, 20% – in the form of cobamide compounds and as part of vitamin B12. Vitamin B12 is synthesized by microorganisms and enters plants from the soil; in nitrogen-fixing plants it is formed in nodules. In plants it is found in legumes, turnips, peas, onions. Up to 30% of compounds are unidentified stable organic compounds.

An activated (coenzyme) form of vitamin B12 – 5,6-dimethylbenzimidazolcobamide coenzyme – has been isolated. In combination with a specific protein, it forms methylmalonylisomerase, which catalyzes the conversion of propionate to succinate.

Cobaltmethylcorrinoid serves as a donor of methyl groups for t-RNA methylation. A coenzyme-dependent ribonucleotide reductase is known. Cobamide coenzymes are involved in DNA synthesis and cell division. The methylation reaction is involved in many processes, for example, in increasing plant resistance to some diseases: the causative agent of Fusarium wilt produces a toxin, Fusarium acid, which forms a non-toxic methylamide derivative as a result of methylation.

Cobalt is a metal with variable valence, which determines its redox potential in various environments in oxidation-reduction reactions. However, it is not found in the composition of the active groups of the respiratory chain enzymes or photosynthesis.

A number of studies have established the connection of cobalt with auxin metabolism and its effect on cell membrane stretching.

Cobalt is required by legume crops in the absence of bound nitrogen. The requirement is 1/330 of that of molybdenum, and the requirement of cobalt for nitrogen fixation is 1/10 of that for nodule growth. Cobalt changes the structure of nitrogen-fixing apparatus, the functioning of bacteroides is more active. Capsules around bacteroides form earlier and last longer. Positive effect on the reproduction of nodule bacteria.

The effect of cobalt on nitrogen fixation is also manifested in its participation in the synthesis of leghemoglobin. Under the influence of cobalt increases the activity of dehydrogenases, hydrogenases, nitrate reductase, increases the content of chlorophyll, total hematin and associated with chlorophyll vitamin E.

With cobalt content in feed less than 0.07 mg per 1 kg of dry hay the animals fall ill with acobaltosis, productivity decreases, with sharp insufficiency of cobalt it is possible death of animals. This conditions the use of cobalt fertilizers in meadows and pastures in areas of cobalt deficiency.

Cobalt content in soil

Under natural conditions associated with the geochemical cycles of iron and manganese, cobalt occurs in ionic forms of Co2+ and Co3+. In an acidic environment, cobalt is mobile and does not migrate in solutions due to sorption by iron and manganese oxides and clay minerals. At low pH values, Co2+ and Mn2+ are exchanged to form Co(OH)2, which precipitates on the surface of oxides. With increasing pH, sorption by manganese oxides increases sharply.

In soil solutions, the concentration of cobalt varies in the range from 0.3 to 87.0 µg/L. The distribution of cobalt in the soil profile is influenced by soil organic matter and the content of clay particles. Montmorillonite and illite clays sorb this element well. Organic chelates of cobalt are mobile, migrate in the soil and are available to plants.

The poorest are sod-podzolic light sandy soils. With liming of soils the need for cobalt increases. Positive effect is shown on soils provided with basic nutrients with a soil solution reaction close to neutral: chernozems, gray soils, cultivated sod-podzolic and chestnut soils. In neutral soils cobalt is in a sedentary form and is inaccessible to plants.

Cobalt fertilizer

Cobalt fertilizers include cobalt sulfate CoSO4⋅7H2O (20-21%), cobalt chloride CoCl2⋅6H2O (24.8%), cobalt nitrate Co(NO3)2⋅6H2O (20.3%).

Application of cobalt fertilizers in agriculture

Under cobalt deficiency conditions of physiological and biochemical processes and plant growth worsen; productivity and yield quality decrease. Cobalt enrichment of plant products is very important. Crop yields take from 5 to 50 g/ha of cobalt.

In experiments on sod-podzolic soils, the yield of sugar beet roots when cobalt fertilizers were applied increased by an average of 3.5 t/ha, sugar content – by 0.8%, resulting in increased sugar yield by 1 t/ha. Lupine yield increase on sod-podzolic soils was 0.12 t/ha of seeds and 6.5 t/ha of green mass (yield on the control – 32.5 t/ha).

Cobalt-containing fertilizers show effectiveness at 1.0-1.1 mg/kg of soil in the Non-Black Soil Zone, 0.6-2.0 mg/kg of soil in the Black Soil Zone, 1.0-1.5 mg/kg of soil in the zone of sierozem and chestnut soils, 0.8-1.2 mg/kg of soil in flooded soils of rice fields in Kuban. However, to grow good fodder and food, it is necessary to apply cobalt fertilizers at 2.0-2.5 mg/kg soil.

Apply in an amount of 200-400 g/ha[1]Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. – Moscow: Kolos, 2002. – 584 p.: ill. (0.5-2 kg/ha[2]Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. – M.: Publishing house of the All-Russian Scientific Research Institute named after D.N. Pryanishnikov, 2017. – … Continue reading) per element. For seed treatment 0.5% and for foliar feeding 0.01-0.1% aqueous solutions of cobalt salts are used. Foliar feeding is carried out before flowering at the rate of working solution 300 l/ha; seed treatment of cereal crops is carried out by half-dry method (10 l/t).

Optimal concentration for foliar dressing of peas is 0.05% solution, for sugar beet – 0.02% solution. Feeding peas is carried out in the phase of 6-7 leaves, sugar beets – at the closing of rows.

Legumes, sugar beets, wheat, rice, and grapes are the most sensitive to cobalt deficiency.

Plants are equally sensitive to shortage and to excess of this element in soil. At high levels in the soil can develop cobalt toxicosis, which for rice, for example, appears at a content in the soil over 25 mg/kg.

The use of cobalt-containing fertilizers is promising on chernozem soils for leguminous crops and grapes, cultivated sod-podzolic soils.


Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.

Agrochemistry. Textbook / V.G. Mineev, V.G. Sychev, G.P. Gamzikov et al. – M.: Publishing house of the All-Russian Scientific and Research Institute named after D.N. Pryanishnikov, 2017. – 854 с.