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Vermicompost

Vermicompost, or biohumus, vermiculture, is a product of manure or organic waste processing by earthworms. It contains macro- and microelements, plant growth regulators (auxin, gibberellin), enzymes (phosphatase, catalase), has biological activity.

In the process of vermicompost formation the number of pathogenic microorganisms (salmonellae) and viruses decreases. Worms feed on all organic matter, which is 20-25% cellulose, such as straw, cardboard, paper, sawdust. Vermiculture abroad is regarded as an element of environmentally friendly agricultural production and is supported by the state in the form of preferential financing and exemption of vermiculture farms from a number of taxes.

The vermiculture method contributes to solving the problems of accumulation and processing of livestock waste:

  • composting of liquid manure (Germany, Italy);
  • recycling of household and industrial waste for fertilizer, e.g., municipal garbage, sewage sludge (USA, Italy, Netherlands);
  • industrial waste recycling for compost (Japan);
  • fat waste recycling (France, Toulouse).

Vermiculture uses the dung worm Euseniasoetieda, the so-called red hybrid Californian worm, bred in the late 1940s in the USA. It is distinguished by its great growth rate, fecundity, and longevity.

In its digestive tract organic remains undergo profound changes: they are decomposed into simple compounds, enriched with calcium, magnesium, nitrates, phosphorus; humic acids are formed; many mineral compounds are transformed into forms accessible to plants. Under the influence of calcite excreted in the esophagus, acids contained in the substrate are neutralized. The organic residues and earth that have passed through the worms’ intestines are discharged in the form of excrements, which constitute vermicompost (biohumus). During a day an adult worm passes through its intestines an amount of food equal to its own body weight. About 40% of this amount is consumed and 60% is excreted as coprolites. Biohumus is characterized by a high water-holding capacity and forms the components of the soil that determine its structure.

Red Californian worm processes almost all kinds of organic waste: manure, poultry manure, waste from fruit and vegetable depots, processing and pulp and paper mills, brewery waste, meat processing plant waste, sewage treatment plant sludge, household garbage.

Table. Chemical composition of biohumus, % (Sheugen et al., 2004)

Indicator
Contents
Indicator
Contents
Humus
25-30
Magnesium
0,6-1,5
Nitrogen
1,5-3,0
Iron
0,6-1,3
Phosphorus
1,8-4,0
Copper
0,03-0,04
Potassium
1,5-3,0
Manganese
0,06-0,09
Calcium
4,5-7,0
Zinc
0,08-0,09

To obtain high-quality compost, the substrate must undergo a fermentation process, which increases the temperature, resulting in the death of weed seeds and pathogenic microflora.

Regulatory requirements for the composition of vermicompost (biohumus) have been developed in various countries of the world. Worm excrement in biohumus should be at least 70% of the dry matter. There are no significant differences in requirements to the composition of biohumus both in Russia and in other countries.

Table. Requirements for the composition of biohumus[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

Indicators
Russia (price list 708201)
FRG
Poland
Farm "Goretskoe" (experiments)
Content of organic matter, %
40-45
40-45
40-60
43-60
C/N Ratio
15
15
15
Available nitrogen content, %
not less than 1.5
not less than 1.5
1,5-3,0
1,8-2,0
Contents P2O5, %
1,2
1,2
1,8-4,0
1,8-3,0
Contents K2O, %
0,5
0,5
1,5-3,0
0,75
Humus, %
не менее 15,0
-
-
20,0
Moisture, %
50,0
40-60
40-60
50-60
рН
6,5-7,5
6,5-7,5
6,8-7,2
7,0-7,1

Vermicompost due to its high content of nutrients, agronomically useful groups of microorganisms and biologically active substances has a positive effect on the growth and development of plants and soil biota. While 1 g of manure contains 150-350 million bacterial colonies, vermicompost contains 100-200 billion. Biogumus is characterized by neutral reaction of environment, pH is usually in the range of 6.8-7.2.

Average doses of vermicompost for application to the soil are 3-5 tons/ha.

The yield of grain crops in the first year after applying biohumus increases by 0,6-1,0 t/ha, potato tubers – by 5-6 t/ha. Biohumus can be used in vegetable growing in open and protected ground.

Biohumus surpasses composts in many respects, has better physical properties – higher water-holding capacity, contains more nutrients available for plants, especially nitrogen, which is explained by higher number of nitrogen-fixing bacteria in worm coprolites. Humic acids, the content of which ranges from 5,6 to 17,6 % of dry matter, add particular value to biohumus.

In foreign countries, biohumus is used mainly as a nutrient substrate for growing seedlings of vegetables and ornamental plants. Due to high production costs, application for field crops is limited.

There are several groups of plants according to responsiveness to biohumus:

  • Vegetable crops, tubers, root crops are characterized by high responsiveness – yield increases are 35-40%;
  • Cereal crops respond well – yield increase up to 25%;
  • Leguminous crops reacts satisfactorily – increase in yield up to 15%;
  • Oil-bearing crops react little.

Sources

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.

Green fertilizers

Green fertilizers (green manure) – fresh plant matter, plowed into the soil to enrich it with organic matter and nutrients.

Siderats – plants grown as a green fertilizer.

Sideration – a method of enriching the soil with green fertilizers.

Green fertilizers have the same effect on soil properties, crop yield and quality of crops as litter manure.

Scientific basis for the use of green fertilizers

1. Green fertilizer is a source of organic matter and nitrogen in the soil. When the green mass of green manure is plowed 35-40 tons/ha, 150-200 kg of nitrogen enters the soil, which is equivalent to 30-40 tons of manure. The coefficient of nitrogen use of green fertilizer in the first year is 2 times higher than that of manure. Legume green manure enriches the arable layer with available phosphorus, potassium and other elements. For example, on light soils in Wubern (UK) annual plowing sideratov for 7 years increased the content of organic matter by 10%, at Rotamsted experimental station application of green fertilizer for 30 years has accumulated organic matter in the soil 35 tons / ha. In Bavaria, Germany, the application of green fertilizer on a loamy soil for 25 years increased the humus content from 2.2-2.3% to 2.8%, while the application of only mineral fertilizer reduced the humus content to 1.9%.

Green fertilizer affects the fractional composition of humus. For example, in long-term experiments on sod-medium-podzolic medium-loam soil, green mass of lupine increased the content of humic acids by 20-30%, the absolute and relative content of fulvic acids decreased. Under Central Asian conditions on typical sierozem soils intermediate crops for green fertilization together with alfalfa in cotton-alfalfa crop rotations improved the humus balance, contributed to mobilization and accumulation of phosphorus available for plants from low-soluble phosphates.

2. Green fertilizer improves agrochemical, physico-chemical and physical properties of soil: excessive soil acidity is neutralized, the amount of absorbed bases increases, hydrolytic acidity and content of mobile aluminum decrease, and the cohesiveness of sandy and sandy loam soils increases.

On gray forest medium-loamy soil of the Northern Trans-Ural Region, plowing of green manure leads to the decrease of the soil volumetric weight of the 10 cm layer by 0,07-0,11 g/cm3, in the layer 10-20 cm – by 0,06-0,12 g/cm3. According to the Don Zone Research Institute of Agriculture, in terms of volume weight reduction, green manure is equivalent to 20-30 tons of manure per 1 hectare. In Dagestan green fertilizers in terracing slopes for 4 years on the average reduced the volume weight in the layer 40 cm by 9,5%, the content of humus in the arable layer has increased by 0,54-0,71%.

3. At the expense of increasing humus content and improving agrochemical and agrophysical properties of soil biological activity of soil increases, soil and above-soil air is enriched with carbon dioxide, air nutrition of plants is improved, activity of soil microflora is activated. The number of microorganisms in the 30-cm layer from plowing the green manure increases by 1.5-2 times compared with control, in combination with mineral fertilizers – 2-3 times.

Plowing of buckwheat stubble for green fertilizer on sod-podzolic medium loamy loamy soils of the Moscow region with a mass of 20-30 t/ha has increased the biological activity of the soil and the content of nitrate nitrogen as a result of intensive mineralization of organic matter.

Positive effect of sowing rape, mustard, rye, barley, Turkmen vetch under winter conditions was obtained in Uzbekistan. Sown in September-October, by the beginning of April they accumulate more than 25-40 t/ha of aboveground green mass, and plowing such an amount of organic matter improves soil properties, activates microbiological activity, increases the content of nitrates, saprophytic microorganisms and actinomycetes. All this contributes to improvement of soil phytosanitary condition, including wilt control, so winter sowing of intercrops in growing cotton, first of all in wilt-infested fields, is recommended.

According to field experiments of Timiryazev Agricultural Academy, the use of green fertilizers in pure form and in combination with straw leads to changes in the species composition of spore-forming bacteria: the proportion of bacilli using mineral nitrogen of soil increases, which is an indicator of intensive decomposition of organic material.

4. Green fertilizer – a link of intensive farming, which performs the function of protecting the environment from pollution. With the development of chemization of agriculture, increasing use of mineral fertilizers, losses of biogenic elements as a result of washout from the surface, migration to the deep soil layers, and increased denitrification are increasing. Moreover, the more arable land is not occupied by vegetation, the greater these losses. Intermediate siderats, especially perennial lupine vegetating in autumn and spring between crops of crop rotation, prevent losses of nutrients, protect against the processes of water and wind erosion, thus being elements of soil-protective farming system.

Fallow crops are used in the irrigated areas of Central Asia, in the humid subtropics of the Caucasus and Transcaucasia.

5. Green fertilizer performs a phytosanitary role. For example, plowed plant mass of perennial lupine reduces the defeat of potato tubers with scab, which is especially important when growing seed potatoes. In experiments of the Research Institute of Agriculture and Livestock of the western regions of Ukraine, on the plots where lupine was ploughed in years with high precipitation, the proportion of affected tubers was 1-2%, while on the plots without lupine – 7-8%.

Phytopathogenic fungi causing root rot cause great harm to crops. Plant residues and seeds are carriers of root rot infection. The faster the decomposition of organic residues in the soil, the faster the fungus is brought out of its dormant state and the soil is free of infection. Root syderats increase the number of actinomycetes, which are antagonists of the root rot pathogen, as well as saprophytic microflora that accelerate the mineralization of plant residues.

Systematic scientifically proven use of green fertilizer in conjunction with other agronomic techniques contributes to the profitability of agricultural production. Especially high efficiency from green fertilizers is noted on light sandy soils with poor agrochemical, physical and chemical, biological and water properties. In areas of the Central Non-Black Soil Zone the share of light soils is about 20% of arable land, in some regions, for example, Bryansk and Vladimir – up to 50-60%.

Chemical composition

According to various sources, 1 t of crude weight of legume siderats contains on average:

  • in lupin – 210 kg of dry matter; 4.5 kg N; 1.3 kg P2O5; 1.8 kg K2O; 5.0 kg CaO;
  • in melilot – 220 kg of dry matter; 7.7 kg of N; 0.5 kg of P2O5; 2.0 kg of K2O; 10.0 kg of CaO;
  • in seradella – 210 kg of dry matter; 6.2 kg N; 2.2 kg P2O5; 5.5 kg K2O;
  • in esparcet – 200 kg of dry matter; 6.2 kg N; 1.2 kg P2O5; 3.2 kg K2O.

Compared with the chemical composition of mixed manure of dense storage, 1 t of which contains 5 kg N, 2.5 kg P2O5 and 6 kg K2O, legume siderats are richer in nitrogen, poorer in phosphorus and potassium. Mixtures of legumes with cereals, as well as non-legume siderates, are also poorer in nitrogen.

Decomposition processes of green fertilizers in the soil are faster than other organic fertilizers containing slowly decomposing substances.

Application of siderates

A distinction is made between independent and compacted (mixed) crops of siderats.

In the case of independent sowing, the field is occupied with legumes from spring throughout the growing season. It can be plowed both under winter crops and spring crops. Green fertilizer occupies an independent field of the crop rotation.

The practice of Russian agriculture shows that as the soil is cultivated and specialized crop rotations are introduced, it is advisable to introduce intermediate green fertilizer, without disturbing the rotation of crops in crop rotations. The use of green fallows (independent green fertilizer) is more suitable for uncultivated, poor in organic matter soils. Therefore, the practice of using pure fallows in the Non-Chernozem zone is not an agronomic progressive technique. In this zone sideral fallows are more effective. To accelerate the cultivation of podzolic soils green fertilization is combined with the application of manure, compost and mineral fertilizers.

Compacted (mixed) crops can be solid, when part of the field is entirely occupied by green manure, and striped with a strip or row alternation of the main crop and the green manure. For example, green manure planted in between the rows of orchards and berry or row crops, across slopes for anti-erosion purposes.

Depending on the time (before or after harvesting the main crop) a distinction is made between under-seeded, that is sown under the main crop, and intermediate (stubble), that is sown after the harvest of one crop and before sowing the other. This green fertilizer includes stubble crops, autumn and winter crops. The latter are sown in September-October and plowed in spring, they are used in the irrigated areas of Central Asia, in the humid subtropics of the Caucasus and Transcaucasus.

Stubble intermediate green manure is sown after harvesting early spring crops, such as barley, and plowed under the autumn plowing. For this purpose, harvesting is carried out quickly and sowing of plants for green fertilizer is carried out after soil preparation. In this case the green manure has time to accumulate a considerable mass.

Lawn grass seeders are also used for sowing to the main crop, for example, melilot is sown in spring to the cereal crop, after harvesting which until the onset of cold donuts have time to accumulate sufficient mass.

Techniques for the use of green manure: full, hay and herbage green fertilizers.

In full green fertilization, the whole mass of the green manure is plowed in place.

Green fertilizer for mowing is grown in the non-rotation field, then transported to the crop rotation fields and plowed. Suitable for this is perennial lupine, the advantage of which is also that it matures to seed even in the conditions of the northern areas of the Non-Black Soil zone.

After-mowing fertilizer is plowed after removing the mowed or eaten by cattle mass of the grown stubble and root residues of green manure. It is used on crops of sod-podzolic soil, especially light granulometric composition. Used in Siberia and the Far East. Winter and fodder peas, chinam and melilot are sown in the irrigated areas of Turkmenistan, Tajikistan, Uzbekistan, Transcaucasia, Kyrgyzstan, Kazakhstan as a after-mowing siderat.

The main areas of application of green manure are poor in organic matter with unfavorable properties of soils of different zones that require cultivation. They are also used when there is a lack of organic fertilizers.

Green fertilizer is widely used in many countries around the world. Almost everywhere intermediate crops are used as a green fertilizer, independent – only on depleted soils and in areas away from livestock farms.

Stand-alone green fertilizer is also used on the plots that came out of the clearance of wood and shrub vegetation during the development of new lands and enlargement of the arable land.

Under intensive agriculture in Belarus and Non-Black Soil zone of Russia perennial lupine is the key green manure. It grows on poor uncultivated soils. When it is used for tilling of soils without violating the scheme of alternation of crops, 30-50 t/ha is plowed at a time. When 3-fold plowing in 8-field crop rotation provides the average annual input of plant matter not less than 14-19 t/ha, 10-field – 11-15 t/ha.

Green manure has a good effect on potatoes planted after winter rye with perennial lupine as an intercrop.

Normally perennial lupine is sown under winter rye. After harvesting, lupine grows until late fall. In spring, vegetation begins just after the snow melts. Before plowing the green manure for potatoes in spring, lupine has time to grow up to 20 tons/ha of green mass, and with root residues, 30-50 tons/ha. After green fertilizer in the rotation can be placed also buckwheat, corn or sunflowers for silage, vetch-oat mixture for green fodder.

Green fertilizer can be used in a zone of sufficient moisture on all soils, as well as in terms of irrigated agriculture, such as in the Volga region, Central Asia and the subtropics of Transcaucasia, the climatic conditions which contribute to rapid accumulation of organic matter. In the Volga region, Rostov Oblast, Krasnodar and Stavropol Krais and other regions of irrigated agriculture, it is advisable to use stubble and sub-sowing siderats.

In the central regions of the Non-Black Soil Region after harvesting winter and early spring cereal crops, fields may remain unoccupied for more than 60 days with the total of active temperatures of 800-1000 °C, which amounts to 30-40% of agroclimatic resources of the warm period of the year. Also, there is a reserve of such resources in the spring period before sowing of late spring crops. This amount of precipitation and heat is enough for cultivation of sub-sowing and stubble crops. This can be done to the south of the line St. Petersburg – Tver – Ivanovo – N. Novgorod – Kazan – Ufa.

In the Non-Black Soil zone, narrow-leaved (alkaloid) annual lupine, fodder annual (low alkaloid) and perennial (alkaloid) lupine are used as a greenhouse crop. Due to the introduction of fodder lupine into the culture, bilateral use of green manure is practiced:

  • green mass of fodder lupine is harvested for silage, and stubble and root residues are plowed under winter crops;
  • fodder lupine is grown for grain; straw and root residues are plowed into the soil;
  • green mass is mowed at the beginning of budding or flowering and used for fodder.

The field is left uncultivated to allow the grass to grow. If the weather is good, the lupine regrows, and the regrowth of grass is ploughed in as green fertilizer. This method allows you to collect 20-30 t/ha of green mass for silage and 10-15 t/ha of mass after its re-growth for green fertilizer.

Syderates

Leguminous crops such as lupine, seradella, melilot, vetch, chinna, sainfoin, astragalus, peas, pelushka, lentils, clover, alfalfa are used as green manure. Mixtures of legume and cereal grasses or intermediate (insertion) non-legume crops are used less frequently: mustard, bittercress, rape, buckwheat, winter rye, phacelia.

The use of legumes for sideration is due to their ability to enrich the soil with nitrogen, due to nitrogen fixation.

Lupins

Lupins annual and perennial with different content of alkaloids are the most common green manure for acidic soils of the Non-Black Soil zone of European and Asian parts of Russia. Alkaloid lupine is used only as a fertilizer, alkaloid-free – above-ground mass for cattle feed, crop and root residues as a after-mowing fertilizer. All lupins have the ability to assimilate phosphorus hard-to-reach phosphate soil and phosphate and bone meal, improve phosphorus nutrition of subsequent crops of the crop rotation. Lupins can also symbiotically fix atmospheric molecular nitrogen, thus improving nitrogen balance in agrocenoses even on poor sandy and sandy loam soils.

Lupins grow well on acidic soils; very acidic soils require liming, sometimes annual lupins do not tolerate liming, perennial lupins only at the beginning of vegetation. One of the reasons of oppression of lupines on very acidic soils after liming is deterioration of phosphorus nutrition: lime prevents uptake of hard-to-removal phosphates. Therefore, lime and phosphate meal are applied to lupins in layers: lime – deep under plowing with skimmers; phosphate meal – under pre-sowing tillage.

Layered application of lime and phosphate meal in combination with potash fertilizers under lupine is an effective method of soil cultivation.

Annual alkaloid lupins – narrow-leaved blue and yellow – grow in independent and mixed crops, plowed as a complete fertilizer in the period of maximum nitrogen accumulation, ie during the formation of shiny beans on the main stem. On seeded fallow lands, the green manure is crushed with discs and plowed at least 2-3 weeks before sowing winter crops. Before sowing winter crops, the field is rolled over so that the soil settles and does not expose the tillering node. With the development of fodder (alkaloid-free) lupins, the cultivation areas of alkaloid lupins remained only in the northern regions of Vologda, Kostroma, partly Smolensk, Vladimir, and Nizhny Novgorod.

Annual fodder lupins are more valuable in combined use, being an additional protein feed for animals and at the same time a after-mowing siderat. They are effective as green fodder and stubble after-mowing fertilizer after harvesting winter rye for green fodder.

Overground mass of fodder lupins in a combined use is mowed in the phase of budding or flowering at a high (8-20 cm) cut, which provides fodder quality with good re-growth of the herbage.

Thanks to its cold-resistance, perennial lupine matures everywhere, up to Arkhangelsk, with a high reproduction rate. It blossoms and forms seeds in the second year, and reaches its maximum green mass in the 3rd-4th year without fertilizers.

In crop rotations, lupines are sown in siderat fallow or under winter rye cover. Also use under-winter seeding as an intermediate crop in the link seeded fallow, winter rye with under-winter seeding of perennial lupine, potatoes.

On very poor soils, in order to improve the state of cultivation perennial lupine is sown in the output fields, wastelands, in intercrops of fruit and berry nurseries, orchards and berry gardens, forest nurseries and on the slopes of ravines. Lupine is left on such plots for 6-8 years and is used as a mowing green fertilizer in nearby fields, berry and orchard nurseries, and in orchard bedding circles.

Melilot

Melilot is annual and biennial, white and yellow, and white is more productive and yellow ripens earlier. This crop grows well on calcium-rich neutral soils. On calcareous sod-podzolic soils, melilot is more productive than annual and perennial lupine. Due to their powerful root system, they are very drought-resistant and cold-resistant. They are valuable as complete and fallow plants even when their above-ground mass is underdeveloped.

Also used as animal feed. Its high coumarin content decreases its fodder quality, but there are varieties which do not contain coumarin.

One-year and biennial varieties are used for complex use; on fields with a big slope, a biennial is more suitable. Forms of application of under-sowing and independent sowing:

  • mowing at the beginning of flowering for fodder and hay fertilization;
  • green mass of the first mowing is used to fertilize other fields (mowing fertilizer), the second – for fodder, after-mowing – for fodder or after-mowing fertilizer;
  • green mass of the first mowing – for fodder, the second mowing – for mowing fertilizer, after-mowing – for fodder or fertilizer;
  • self-sowing as a fallow-occupying crop with plowing for fertilizer under winter crops.

Seradella (Ornithopus)

Seradella (Ornithopus) is an annual moisture-loving legume grass, prefer light slightly acidic (pH 5.0-5.5) soils, can use hard-soluble phosphates and phosphate meal. On sandy and sandy loam soils it responds well to potassium and magnesium fertilizers. On moisture-enriched soils is more effective as an under-seeded crop under the cover of spring and winter (spring) cereal crops. The earlier the cover crop is harvested, the higher the productivity of seradella. Cultivation of seradella on fields which are weed-free, sufficiently moist and early harvested is also effective.

Self-sustained or inserted (intermediate) seradella crops are used as full, mowing and after-mowing fertilizer, more effective a complex application: for cattle feed (mowing or after-mowing) and green fertilizer (mowing, after-mowing or root and stubble residues).

Using stubble residue as green fertilizer

Stubble residue (stubble and roots) is an item of income in the balance of organic matter, is a type of after-mowing green fertilizer.

The quantity and quality of post-harvest residues depend on the biological characteristics of crops, within one species – on the variety, productivity, soil and climatic conditions. Possible amounts of post-harvest (stubble) residues vary (in t/ha dry matter): Annual lupins 0.5-1.5 t/ha, perennial lupins 2.0-3.0 t/ha, clover 3.0-7.0 t/ha, alfalfa 4.0-9.0 t/ha, peas 1.5-3.0 t/ha, winter rye and wheat 2.2-6.5 t/ha, barley 2.0-4.5 t/ha, corn 1.5-6, 0 t/ha, potatoes 0.8-1.2 t/ha, sugar beets 1.0-1.5 t/ha, rye for green fodder 1.0-2.0 t/ha, winter mustard 0.5-1.5 t/ha, mustard 0.4-1.0 t/ha, perennial cereal grasses 5.0-11.0 t/ha.

In terms of reduction of stubble and root residues, crops are arranged in the following sequence: perennial cereals – cereals-legumes – leguminous grasses – corn – winter cereals – spring crops – winter green forage – sugar and fodder beets – potatoes – stand-in (intermediate) crops.

Nitrogen balance due to symbiotic nitrogen fixation is influenced only by legumes and leguminous crops in pure and mixed crops. Nitrogen content in the roots of legume crops reaches 2.0-2.5%, in non-legume crops – no more than 0.5-1.0% on a dry weight. Therefore, post-harvest residues of perennial alfalfa in terms of dry matter and nitrogen content are equivalent to 40 t/ha of manure, clover and clover-timothy grass mixture – 20-25 t/ha.

Cereal perennial grasses take first place by mass of stubble and root residues, but due to low nitrogen content (0.5-0.7%) their C:N ratio is wider than that of legumes. Therefore, when mineralizing residues, microorganisms immobilize forms of soil and fertilizer nitrogen in the same way as when plowing straw for fertilizer.

The amount and quality of post-harvest residues entering the soil is regulated by the structure of cropping areas and intermediate crops, which is taken into account when determining the needs and locations of organic fertilizers in the agrocenosis.

Effectiveness of green fertilizers

The effectiveness of green fertilizers depends on the type, productivity and method of use of green manure. The more and better quality green mass of green manure plowed for fertilizer, the higher is the effect and aftereffect.

The rate of decomposition of green fertilizers depend on the granulometric composition and moisture content of the soil, the phase of plant development at the time of plowing, embedding depth. With an increase in the depth of embedding, age of green manure and the content of clay particles in the granulometric composition mineralization of green fertilizers slows down. Adding small rates of manure, poultry manure, fecal matter and other components rich in microorganisms to green manure during plowing accelerates the rate of mineralization.

Providing a favorable environmental reaction and optimal nutrient regime is a factor in increasing the effectiveness of crops and methods of application of green fertilizers.

Legume siderats due to symbiosis with nodule bacteria are able to satisfy their own and partially following cultures, the need for nitrogen. Methods to increase the nitrogen-fixing ability of legume crops are inoculation of seeds with active races of nodule bacteria and treatment with molybdenum fertilizers (20-25 g Mo per hectare seed rate).

The nodule bacteria are specific and can actively interact only with a particular type of legume crops. The strains of nodule bacteria differ in virulence, i.e. the ability to penetrate the root and form nodules, and activity, i.e. the ability to assimilate molecular nitrogen of the atmosphere. Bacterial preparations for legume seed treatment include nitragin and rhizotorfin, which are specific for each crop and contain virulent and active bacterial strains.

For a hectare norm of seeds, 500 g of the preparation is used, and only the part of seeds which is applied on the same day is treated. Inoculation can be combined with molybdenum fertilizer treatment by dissolving fertilizer and bacterial preparation in one portion of water. However, it cannot be combined with seed dressing, which should be carried out 3-4 weeks before sowing, it can also be combined with treatment with molybdenum fertilizer.

Increase in rye grain yield from lupine green fertilizer is 0.42 t/ha on sandy soils, on sandy loam – 0.47 t/ha, on loam – 0.77 t/ha (the average of 36 experiments). Green fertilizers show high efficiency on other crops, on light soils, their effect is noted for a number of years.

Sources

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.

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

Composts

Composting is a biothermal process of mineralization and humification of one or more organic components, sometimes with the addition of mineral fertilizers and ameliorants, reducing the loss of nutrients, accelerating the decomposition of organic matter and increasing the availability of nutrients to plants.

The composting of organic waste is thermally decontaminated, with the temperature rising to 60 °C, which kills eggs and larvae of flies and helminthes, pathogenic non-native microorganisms, and suppresses weed seeds.

In organic composts, one of the components may act as an absorber of moisture, ammonia, and carbon dioxide, and it may decompose poorly without composting, such as peat, sawdust, household garbage, sod soil, and straw. Some components may be enriched with microflora, such as manure, slurry, feces, poultry manure, and contain large amounts of degradable nitrogenous and nitrogen-free organic compounds.

The degree of decomposition and homogeneity of the mass is the measure of compost readiness.

Peat-manure composts

Peat-manure composts are prepared near livestock buildings, in manure storages or in field stacks. The ratio of manure and peat depends on the quality of components and their availability in farms. In winter, the ratio is usually 1:1, in summer up to 1:3. Any peat with a moisture content of up to 60% is suitable for composting.

Layer composting is used at any time of the year. For this purpose, the peat is leveled by a layer of up to 50 cm on the prepared places with a width of 4-5 m of any length. Then it is covered with a layer of manure, which is again covered with peat. The layers of peat and manure alternate until the stack is 2 m high. The thickness of the layers depends on the ratio of the components. Top the stack with a layer of peat.

Focal composting is preferably used in winter. For this purpose manure on a prepared 50-60 cm layer of peat is placed in a continuous or discontinuous layer 70-80 cm thick and 1.0-1.5 m wide less than the underlying peat. If there is a shortage of manure, it is placed by intermittent layer (piles) with all sides covered with a layer of peat 50-70 cm. In winter, a stack of hearth compost is placed 1-2 days in advance, preferably during thaws, then the temperature inside does not drop below 25-30 °C.

In layer-by-layer and focal composting, to improve the quality of peat with manure, 1.5-3.0% (15-30 kg/t) phosphate meal is added to the mixture. This produces peat-manure-phosphoritic composts, which are as efficient as good manure with a content of 30-50%. Phosphoric flour is poured over layers of peat and manure.

When composting manure and peat with phosphoric flour, along with potash fertilizer at the rate of 1 ton of peat 5-6 kg of fertilizer. Depending on the acidity, lime fertilizer is added additionally, and phosphoric flour in this case is added to the manure, and potash and lime fertilizer – to the peat. The efficiency of such compost at equivalent rates is higher than that of manure.

Peat-slurry composts

Peat is composted with sewage, liquid and semi-liquid manure in the same way as with slurry.

Peat-slurry composts are prepared with any peat, except lime peat containing more than 5% of calcium, in winter in manure storages or next to livestock buildings, in summer – in field stacks and on drained peatlands. For 1 ton of aerated peat, depending on the moisture content, 1-3 ton of slurry and 1.5-2.0% of the mass of the compost phosphate meal are added. The peat is placed in two adjacent shafts with a trough-shaped depression between them, in which the slurry is poured.

After the absorption of slurry by peat, the mass is raked into stacks, covered with peat and compacted when the temperature reaches 60 ° C. Depending on the properties of components and the ambient temperature mass kept for 1-4 months. Used as a main fertilizer for crops in the same doses as the litter manure. Peat-slurry-phosphate composts are as effective as good manure.

Peat-fecal composts

Peat-fecal composts are produced by composting fecal matter with peat or straw, municipal garbage, and other low-degradable materials. Fast-acting organic fertilizer. Fecal matter contains on average 0.5-0.8% N, 0.2-0.4% P2O5 and 0.3-0.4% K2O. 70-80% of nitrogen is in the form of ammonia compounds and urea, phosphorus and potassium are in plant-available forms. Dried fecal matter (powders) contains 2% N, 4% P2O5 and 2% K2O. To reduce nitrogen losses during drying of fecal masses, 8-10% of dry peat powder is added to them. Powders are used under ornamental and bast crops at a dose of 2-3 t/ha. By efficiency are not inferior to equivalent doses of mineral fertilizers.

For sanitary, agronomic and environmental reasons fecal matter is better to use in the form of composts. For their preparation to 1 ton of lowland peat with a moisture content of 70% add 0.5 tons of feces to 1 ton of highland peat – 2 tons, when wet peat to 50% – up to 3.5 tons of feces. To decontaminate and reduce the loss of nutrients, composting must proceed at a temperature of 56-60 °C followed by compaction. The method of preparing compost is similar to that for slurry compost.

In the second year after laying, peat-fecal compost can be applied to any crops, except vegetable crops, at a dose of 10-25 tons/ha.

They often surpass manure in equivalent rates of nutrients by 30-50% in terms of efficiency.

Peat-mineral composts

Peat-mineral composts may contain lime, ash, phosphate meal, liquid ammonia and other mineral additives.

Peat-lime and peat-ash composts are prepared with acidic peat (pH of salt extract less than 5), pouring them over 15-20 cm layers when laying the stack. The dose of lime is calculated by 0.8 hydrolytic acidity (Hg) of peat, that is, when the moisture content of peat 60-70% on average 1-3% of the mass of the compost. The best form of lime fertilizer in this case is dolomite flour. Composts are kept before application for 4-5 months. Poor in potassium and phosphorus.

To enrich calcium, phosphorus and potassium composts are prepared with ash, with the additional neutralization of exchange acidity. The stack is prepared in the same way as with lime, adding 2.5-5.0% ash (25-50 kg/t) per 1 ton of aerated peat.

Peat-phosphate composts with a good mixing of the components already in a month of storage convert 30-60% P2O5 phosphate meal in the form assimilable for plants with a simultaneous reduction in the acidity of the peat.

To prepare these composts acid peat is used, which does not contain mobile forms of aluminum. Per 1 ton at 65-70% moisture content is added 10-30 kg of phosphate meal and kept 2-3 months.

Peat-lime and peat-phosphate composts are used in the same rates as manure. Their effectiveness increases when combined with nitrogen-potassium mineral fertilizers.

Peat-ammonia and peat-mineral-ammonia fertilizers (composts) are prepared by saturating the peat with liquid ammonia or its aqueous solution with the addition of phosphorus and potash mineral fertilizers. For these suitable peat ash content up to 25%, humidity 55-65% and the degree of decomposition of the lowland 15-20%, for the highland – 20-25%. For 1 ton of dry peat in the peat-mineral-ammonia fertilizers composition, 30-35 kg of phosphate meal or its mixture with superphosphate in the ratio 1:1, 10-12 kg of potassium chloride or other potassium fertilizers, 30-35 l of 25% ammonia solution or the equivalent dose of liquid ammonia by NH3 are used. In peat-mineral-ammonia fertilizers based on lowland peat, the amount of mineral components is reduced by 30-50%.

Composts prepared on peatlands

Preparation of compost on drained peatlands near fertilized fields reduces the cost and increases their efficiency.

The technology of compost preparation on peatlands is a combination of their treatment and loosening with the introduction of organic and mineral components, such as manure, slurry, fecal mass, lime, phosphate meal, with subsequent raking and compaction of mixtures in stacks.

When calculating the quantities of components and compost, take into account that at a mass of 1 m3 of 400 kg and the depth of the raked layer of 20 cm on each hectare of peatland for the season receive 800 tons of peat.

Peat-plant composts

Peat-plant composts are obtained by growing legumes or green manure crops on peatlands with subsequent plowing and preparation of stacks of the resulting mixtures of peat and plants.

Plant mass of green manure in the flowering phase is dug, crushed and plowed to a depth of 15 cm. After 2-3 weeks, the peat is disked, and the peat-sideral mass is raked into stacks 1.5-2.0 m high and left to stand for 1-2 months. Peat-plant composts are used for crops in the same doses as litter manure. In terms of efficiency in equivalent rates they are not inferior to semi-decomposed manure of dense storage.

Composts from household waste

In connection with the requirements for environmental protection and an increase in the amount of household waste, industrial methods of biothermal decontamination of waste and the preparation of composts on their basis are widespread. The average content of plant composts (% on dry weight) is 40-52 % of organic matter, 1-1.3 % N, 0.7-0.8 % P2O5, 0.4-0.6 % K2O, 3 % of crushed glass <15 mm, 4 % of foreign inclusions. The moisture content of the composts is 30-40% and the pH of the salt extract is 6.0-7.8.

In terms of the effect on the crop, compost from household waste is not inferior in equivalent rates to manure. Application requires agrochemical control for the presence of hazardous impurities.

Sources

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

Sewage sludge

Use of sewage sludge

The growth of urban population, development of industry is accompanied by an increase in the volume of wastewater and its sludge. In industrially developed countries an average of 19-25 kg of dry sewage sludge is produced per inhabitant per year. In the Russian Federation, the estimated average annual volume of dry sludge yield is 2.5 million tonnes.

In towns and large settlements, the volume is estimated to be 0.5-1.0 % of the treated waste water. Fresh sludge from primary sedimentation has a water content of 92-95 %. The sludge is disinfected and dewatered. Depending on the technology, sewage sludge is composted, fermented or thermally dried.

During sludge fermentation decontamination is carried out in digesters at a temperature of 56-58 ° C, where the sludge of primary sedimentation tanks and activated sludge are fed in a ratio of 1:1. Fermented sludge is dried on sludge platforms to a moisture content of 60-80%.

In industrialized countries up to 32% of sewage sludge is used as an organic fertilizer.

Table. Production and use of sewage sludge (V.F. Ladonin, G.E. Merzlaya, R.A. Afanasiev et al., 2002).

Country
Population, mln.
Dry matter production per year, thousand tons
Disposal, %
agriculture
dumping
burning
ocean dumping
specific use
Sweden
8,3
210
60
30
-
-
10
Finland
4,8
130
40
45
-
-
15
Denmark
5,1
130
45
45
10
-
15
Germany
59,7
1950
38
50
8
2
2
France
54,2
510
23
46
31
-
-
Belgium
9,8
22
10
80
10
-
-
Luxembourg
0,4
11
90
10
-
-
-
Netherlands
1,4
201
53
32
3
13
2
Ireland
3,5
197
4
51
-
45
-
United Kingdom
56,1
1240
45
29
3
23
-
Switzerland
6,5
120
70
30
-
-
-
Italy
57,2
800
20
60
-
-
20
USA
232,6
3200
25
*
*
*
*

*No data available.

In the Russian Federation only 5-7% of sewage sludge is used for fertilizer, which is connected with insufficient implementation of technologies for the preparation for use in agriculture.

The main technological stage of sludge preparation for use is decontamination. Currently, waste water treatment plants use methods of chemical, thermal and biological decontamination of sewage sludge.

Chemical sludge decontamination consists of treatment with fungicides. The humidity of the product is about 60 %, which makes it difficult to spread over the fertilised area. Thermal decontamination produces dried sludge with a moisture content of less than 60 %. The decontamination takes place at 56-58 °C.

Depending on the treatment technology, sludge for use as fertilizer can be liquid with a moisture content of 92-97%; dried or dewatered with a moisture content of 60-80%; dried with a moisture content of 10-40%.

The optimal timing of sewage sludge-based fertilizers is the fall under the main treatment, as well as the summer for the treatment of fallow and early-release crop rotation fields. During the autumn and spring periods soluble compounds, especially chlorine, contained in sludge are washed out of the root layer. On poorly and medium cultivated sod-podzolic soils, fertilizers are applied at the rate of 10-15 t/ha in dry matter, on well cultivated sod-podzolic sandy loam and black soils – 5-10 t/ha. Application of sludge is combined with the application of mineral fertilizers.

Chemical composition of sewage sludge

The chemical composition of the sludge varies greatly, depending on the production technology and the composition of the treated wastewater.

In thermal drying sludge dewatered on centrifuges or vibrofilters to 80% moisture content is dried at 600-800 ° C to a moisture content of 40%.

The chemical composition of sewage sludge includes nitrogen, phosphorus and calcium, poor in potassium. The amount of organic matter in raw sludge is up to 75% in terms of dry matter and consists mainly of proteins, carbohydrates, fats, lignin and bacteria. The composition includes trace elements: manganese 500-2000 mg/kg dry matter, copper 1000-5000 mg/kg dry matter and zinc 1200-6000 mg/kg dry matter. Ash composition is specific and is determined by the composition of industrial water.

Table. Composition of sewage sludge, % on dry matter

Sewage sludge
Nitrogen
P2O5
K2O
CaO
MgO
total
mobile
From primary sedimentation tanks
1,6-4,0
-
0,6-5,2
0,2-0,6
11,8-35,9
2,1-4,3
Fermented
3,07 (1,7-6,0)
0,27
2,33 (0,9-6,6)
0,210 (0,2-0,5)
3,48 (12,5-15,6)
- (1,5-3,6)
Fermented with activated sludge
3,93 (2,4-6,5)
0,70
3,70 (2,3-8,0)
0,180 (0,3-0,4)
3,29 (8,9-16,7)
0,95 (1,4-11,4)
Thermally dried
1,96 (1,0-3,0)
-
3,92 (2,0-6,0)
0,007 (0,5-1,0)
5,21 (13,0-40,0)
5,81 (4,0-10,0)

Sediments contain heavy metals, petroleum products, detergents and other hazardous compounds. Therefore, their use requires continuous monitoring of the composition. It is safer to use sewage sludge on heavy, humusy soils. On light and poorly humus soils they are used in combination with chemical melioration.

According to the content of heavy metals most of the sediments meet the international agro-ecological requirements.

Table. Content of heavy metals in sewage sludge, mg/kg dry matter (Ladonin V.F., Merzlaya G.E., Afanasiev R.A. et al., 2002)

Element
Moscow
St. Petersburg
Shchekino
Sochi
Maximum allowable concentrations in Western European countries
EU Directives
Russian norms by group
I
II
Ag
4-86
-
-
-
10-100
-
10
20
Hg
0,2-11
-
-
-
6-10
16
7,5
15
Pb
20-325
100
27
300-900
750
250
500
Cb
8-175
60
0,9
6
8-15
20
15
30
Ni
32-880
220
10
< 100
26-500
300
200
400
Cr
265-4700
910
2
40-1000
750
500
1000
Mn
50-1860
305
810
500
-
-
-
Zn
560-7900
1450
51
1662
2000-10000
2500
1750
3500
Cu
69-1740
1250
3
381
300-3000
1000
750
1500

Sludge intended for use as fertilizer must contain not less than 40% of organic matter, 1.6% of nitrogen, 0.6% of phosphorus (P2O5), 0.2% of potassium (K2O), moisture – not more than 82%.

Doses of sewage sludge from the sludge platforms are from 20 to 50 t/ha depending on the chemical composition and content and hazardous substances, as well as the needs of crops and the state of cultivation of soils.

It is advisable to use the sludge for fertilizing parks, tree nurseries, lawns and bast crops, for other crops – with the permission of the sanitary and hygienic control authorities. Sewage sludge is not used for vegetable crops.

Composting of sewage sludge

In composting, fresh sediments are dried to a moisture content of 50-55% and mixed with peat in a ratio of 3:1. Then they are raked in stacks, the temperature in them reaches 60 ° C, which leads to the death of non-spore microorganisms, eggs and larvae of worms and flies.

When using household solid waste and sawdust as fillers, the ratio filler-sludge is taken respectively from 0.5:1 to 1-1.5:1 in the summer and from 1:1 to 2-3:1 in the winter. All types of peat are suitable for composting with sludge. Compost with peat can be made at any time of the year. The proportions of sludge and peat depend on the quality of the peat and the time of composting. In winter, for good warming of the compost, the relative content of peat increases to 2-1.5:1. In spring and summer, the ratio is 1.5-1:1. The quality of the compost increases with the addition of lime at a rate of 15-20 kg/t compost. The maturing period is 1.5-2 months in summer and 3-4 months in winter. The end of composting is determined by the absence of helminth eggs in samples of compost taken at a depth of 0.5 m. If properly prepared, the compost contains at least 50% organic matter, 1.8-2.0% total nitrogen, 1.0-1.2% total phosphorus and 0.2-0.5% potassium per dry matter at pH 6.7-7.0.

The condition for using sewage sludge and composts as fertilizer is to comply with environmental requirements. They are used on flat areas not prone to water erosion, with a groundwater table not higher than 40 cm from the soil surface. When applying on reclaimed areas along the main canals leave protective strips with a width of at least 30 m.

Sources

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.

Industrial and municipal waste

Industrial waste

Some industrial waste containing organic matter can be used as an organic fertilizer, thus achieving:

  • increased crop yields;
  • industrial production becomes more economical and gets rid of the costs of storage and disposal of waste.

Industrial organic waste used as fertilizer is divided into three groups:

  1. Waste requiring composting. This group includes wastes that are dangerous in sanitary, helminthological, entomological and phytosanitary respect, such as waste feathers, down, husks of oil seeds, cranberry and apple press cake, pomace from grapes, wine sludge.
  2. Wastes requiring advance application such as pulp and mash, grape seed grist, bristle factory waste, wool shop sweepings, cuttings from felt products, wool waste and wool dust. Often, these are wastes with a wide ratio of carbon to ammonium nitrogen (C:NH4). When applied directly to the soil before sowing, there is a temporary biological fixation of available soil nitrogen by microorganisms, which leads to nitrogen starvation of plants and reduces yields. Therefore, they are applied long before sowing – under the main tillage, before sowing nitrogen fertilizers are applied.
  3. Waste suitable for fertilizing without restrictions.For example, pork and beef slurry (processing waste), raw fish waste, wastes of skin dressing, glue production waste, horn and halalite chips, silk pupa, silk down, silkworm excrement, tobacco and tobacco dust, tobacco leaves after nicotine extraction, castor oil grist, castor oil cake, cotton, oilcake, rape seed press cake, supremium press cake.

The maximum application rates of industrial wastes in the soil are usually 80-100 kg of total nitrogen. Up to 6 t/ha can be applied by manure spreaders or in mixtures with manure and compost.

Wood bark and sawdust

Tree bark, which makes up 10-20% of the total tree volume and is accumulated at tree processing plants, can serve as an organic fertilizer. Tree bark and sawdust are used for mulching and as fertilizer, preparation of artificial soil for greenhouse and greenhouse farms, as bedding at poultry farms and poultry farms with subsequent use as fertilizer.

Stocks of woody greens in the Russian Federation exceeds 20 million tons per year, of which less than 10% is used. Woody bark contains the main nutrients, which in the process of mineralization become available to plants. It has a good humus-forming potential; in the process of mineralization carbon dioxide is released, thus improving air nutrition of plants.

Woody bark contains 33-35% cellulose, 22-30% lignin, 5.3-12 mg/100 g potassium, minor amounts of phosphorus. The strength, elasticity, high filtration capacity of bark improves the water-physical properties of the soil, its hard-to-degrade part enriches the soil with lignin and tannins involved in humus formation. The disadvantage of bark as a fertilizer is that it does not contain plant-available nitrogen. The ratio of carbon to nitrogen is 140:1. Ash content of pine bark is 2.8%, spruce bark 3.1-5.9%. Acidity is pH 4.8-5.7. Bark is biologically active: it contains a large number of bacteria and mold fungi.

Wood bark is plowed into the soil to a shallow depth. When you apply 125 m3/ha the soil structure improves, the moisture capacity increases. When non-composted bark is applied, nitrogen fertilizers are additionally required for normal life activity of microorganisms that contribute to bark decomposition. Decomposition of conifer bark crushed to 5 cm takes about 2 years.

Other uses of wood bark are composting with mineral and organic additives, and as biofuel, mulch and substrates in protected areas.

Methods of composting: layer-by-layer, focal, area-by-area.

Bark composting is most effective in bunches (piles) 3.0-4.0 m wide at the base, 1.5-2 m high, and at least 4.0 m long. When composting in winter, to avoid freezing, the height of the pile is increased to 2-5 m and the length to 10 m. The weight of the stack is 100-120 tons, as the weight of less than 60 tons the stack freezes. The temperature during the composting period reaches 40-60 °C.

The finished compost must contain at least 80% of organic matter per dry weight at moisture no higher than 60%, 10-15% of humic acids from the total organic matter, pH of the water extract – at least 5.5, the ratio of C:N – no more than 30:1, nitrogen, phosphorus and potassium – respectively 3.0%, 0.1% and 0.1% of dry weight. The density is 0.18-0.3 g/cm3, a lumpy structure and moisture capacity of 250-350 g of water per 100 g of dry matter. Due to the calcium content compost is a meliorant for acidic soils. Compost helps to reduce the incidence of root rot and suppresses the development of nematodes.

The use of bark-based composts can provide greenhouse and greenhouse facilities with high-quality soils.

Sawdust has a similar use in agriculture. All kinds of sawdust improve the physical properties of soils, increase porosity and water retention capacity, reduce the density of heavy clay soils. As well as wood bark, sawdust contains little nitrogen, so the most effective way to use them is composting with nitrogen fertilizers.

Hydrolysis lignin

Hydrolysis lignin is the main waste product of the hydrolysis industry, which makes up to 40% of the weight of the feedstock. When unloaded from the hydrolysis unit, it retains the shape of particles of the feedstock with a dark brown color. According to the chemical composition is a complex of substances, the bulk of which – the products of condensation and polymerization of natural lignin. Also present are non-hydrolyzable polysaccharides, unsaturated sugars, humic substances, organic acids, sulfuric acid, and ash elements. The first two, lignin and polysaccharides, account for 84-91% of the weight of hydrolyzed lignin. Polysaccharides account for 24-45% and lignin for 39-70%. Lignin has an acidic reaction, with a moisture content of 63-75%.

Table. Agrochemical indices of hydrolysis lignin (in recalculation on dry matter) (Tsurkan M.A., Russu A.P., 1980).

Indicator
Hydrolysis lignin
Hydrolysis sludge
Humidity, %
63,1-75,1
61,9-89,6
Ash content, %
3,5-14,7
4,2-72,5
Total carbon, %
42,9-50,8
12,5-53,0
Humic acid carbon, %
3,4-6,4
5,2-18,4
Fulvic acid carbon, %
3,7-7,7
3,0-6,4
Total nitrogen, %
0,34-0,54
0,62-2,32
Nitrate nitrogen, mg/100 g
0,1-0,7
0,5-2,5
Ammonium nitrogen, mg/100 g
2,2-7,6
133-389
Nitrogen easily hydrolyzable, mg/100 g
40-79
183-1470
Total phosphorus, % P2O5
0,01-0,16
0,39-2,46
Total potassium, % K2O
0,01-0,22
0,14-0,33
Total calcium, % CaO
0,20-1,19
0,16-4,07
Total sulfur, % SO4
0,41-2,23
0,64-9,28
рНwater extraction
1,9-4,7
3,0-4,6

Among the nutrients it contains a large amount of sulfur and calcium. Phosphorus and potassium contain on average 0.06% and 0.09% of dry matter, respectively. The content of total nitrogen in hydrolysis lignin is 0.34-0.39%, 14% of which is hydrolysable. The C:N ratio ranges from 75:1 to 117:1.

The return of organic matter lignin into the biological cycle contributes to the protection of the environment from pollution and increases the total production of local fertilizers.

The disadvantages of using lignin as a fertilizer are related to its acidity and low content of nitrogen, phosphorus and potassium. The positives are: improvement of air permeability, porosity, soil structure and physical and chemical properties. It has the ability to adsorb the nitrogen of mobile nitrogen-containing fertilizers, enter with it in a chemical bond, thereby reducing the washout of nitrogen from the upper layers of the soil and increasing the rate of plants.

An industrial method of composting lignin with mineral fertilizers and treating the compost with an ammonia solution before applying it to the soil has been developed. To prepare composts, lignin is pre-neutralized with dolomite flour at the rate of 30-35 kg per ton of fertilizer. The most effective lignin-manure composts have a ratio of manure and lignin of 1:1. For the preparation of 100 tons of compost, 48.2-48.5 tons of lignin with a moisture content of 60%, 1.5-1.75 tons of dolomite meal and 50 tons of manure are used. To accelerate maturation, the piles are made to a height of 1.5 m and the mixture is well mixed. In the raw mass of the compost contains: N – 0,36%, P2O5 – 0,32%, K2O – 0,34%, pH 5.7. The efficiency of the lignin-manure compost is not inferior to the peat-manure compost.

Household waste

Household waste and municipal garbage, such as kitchen waste, paper, rags, dirt, dust, ash, can be comparable to litter manure in terms of nutrient content and fertilizing qualities. The rate of their mineralization in the soil depends on the amounts and ratios of the components. With large amounts of food waste and dust, litter decomposes quickly; it can be applied as fertilizer without composting. If paper and rags predominate, the rate of decomposition is lower, so composting is more effective.

Household waste is 0.15-0.25 t/year per capita in Russia. They often include up to 30-40% organic food components and 20-30% paper. The chemical composition of household waste varies greatly. On average they contain 40-70% organic matter, 28-30% ash, 23-37% carbon, 0.75-1.15% nitrogen and 2.0-5.5% calcium. Per dry weight: 0.6-0.7% N, 0.5-0.6% P2O5 and 0.6-0.8% K2O.

Household waste is highly biologically contaminated, can pose an epidemiological hazard, and requires decontamination. This problem is solved by disinfection in landfills, incineration, biothermal disinfection in the production of compost at the plants.

Decontamination of garbage by long-term composting in landfills, although common, but in sanitary and hygienic terms – unpromising. Disinfected garbage without removal of impurities from the landfills is not suitable for use as a fertilizer. The use of such garbage leads to the littering of fields with metal, glass, bricks, plastics, plastic film and other wastes.

A better way to decontaminate and recycle household waste is field composting.

Industrial biothermal decontamination and processing into compost and biofuel of household waste is now spreading.

Household waste arriving at the plant is subjected to separation: ferrous metals are extracted by electromagnetic belt separators, then the waste is treated with air and water at a temperature above +40 ° C. The garbage is self-heated to 60-70 ° C and decontaminated for 3 days.

The resulting compost contains 40-52% of the dry weight of organic matter, 1.0-1.3% – nitrogen, 0.8-0.7% – phosphorus and 0.4-0.6% of potassium. The presence of up to 3% of glass with a particle size of not more than 15 mm and 4% of foreign inclusions is allowed. The moisture content is 30-40%, and the pH is 7.8.

Industrial compost from municipal solid waste can be applied to fruit crops in an amount of 50-150 tons/ha, grapes – 20 tons/ha, cereals – 20-50 tons/ha, sunflowers, corn – 30-100 tons/ha. Yield increase depending on culture and soil is 10-50%. Compost is safe in sanitary-hygienic, helminthological and entomological respect. Autumn application is preferable. Due to the lead and zinc content in the compost, their use for vegetable crops is prohibited.

As a pre-sowing fertilizer for the main tillage, garbage without pre-composting can be applied to different crops in doses of 20-60 t/ha. In protected ground it is effective in greenhouses and greenhouses as a biofuel, after which it becomes a homogeneous, crumbly and decomposed organic fertilizer for open ground. After composting or use in greenhouses, the decomposed homogeneous trash is applied to crops in doses up to 20 t/ha.

Sources

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.

Sapropel

Sapropel (from the Greek sapros – rotten and pelos – mud, silt) – bottom sediments of freshwater reservoirs, from pink to dark brown in color, the natural color changes in the air. It is organomineral compounds. Sapropel is formed from the remains of plants and animals, contains mineral and organic impurities, dries slowly, after drying it becomes solid and does not get wet again. It contains humic acids, fulvic acids, hemicellulose, cellulose, bitumen, ash (on average 20-60%).

The sapropel reserves in Russia are estimated at 92 billion tons in terms of 60% moisture, in the Republic of Belarus – 2,76 billion m3.

Sapropel is extracted by dredgers with pulp filling in settling tanks; during the first year it is dehydrated, while during the second year it is dried after freezing, which promotes its loosening, and then it becomes a loose mass with approximately 50% humidity. In the first year it is possible to apply directly to the fields, where after freezing and natural drying it turns into a loose mass of moisture of about 80%.

Chemical composition of sapropel

The composition of the organic mass of sapropel, depending on the deposits is: humic acids – 11.3-43.4%, fulvic acids – 2.1-23.5%, non-hydrolysable residue – 5.1-22.6%, hemicellulose – 9.8-52.5%, cellulose – 0.4-6%, water-soluble matter – 2.4-13.5%, bitumen A – 3.4-10.9%, bitumen C – 2.1-6.6%, total nitrogen – 0.6-2.6%, phosphorus – 0.14-0.19%, calcium – 2.5-43.8%, magnesium – 0.3-2.3%. The content of organic matter – from 12 to 80%, ash – from 19 to 88% (in dry matter), including up to 20-30% of calcium and magnesium carbonates. The technical conditions regulate the requirements for sapropel fertilizers.

Table. Physical and chemical characteristics of sapropel fertilizers[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

Name of parameter
Norms by type of fertilizer
Organic
Organo-silica
Organ-lime
Mass fraction of particles larger than 10 mm, %, max
20
20
20
Mass fraction of moisture, %, max
60
60
50
Ash content, %, max
50
70
65
Mass fraction of total nitrogen, % per dry product, not less
1,5
1,0
is not regulated
Exchangeable acidity, pH, not less
5,0
5,0
is not regulated
Mass fraction of calcium oxide, %, not less
-
-
17
Specific activity of radionuclides (cesium 137), Bq/kg
no more than 300

Nitrogenous substances of sapropel are presented in high-molecular compounds, so the forms of nitrogen and phosphorus available for plants are 2-3 times less than in manure, potassium – a negligible amount.

Sapropel contains a large number of trace elements in 1 kg of dry matter: 200-1000 mg of manganese, 10-400 mg of zinc, 10-200 mg of boron, 2-60 mg of copper and 1-20 mg of molybdenum. Depending on the location of the reservoir can contain large amounts of heavy metals.

The composition of the sapropel can vary greatly depending on the location of even one body of water.

Table. Average composition of various sapropels (from different sources)[2] Yagodin B.A., Zhukov Yu.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

Type of sapropel
Content, % on dry matter
Organic matter
Ash
N
P2O5
CaO
MgO
Low ash
80
19
3,4
0,14
2,5
0,5
Medium ash
60
38
2,6
0,18
2,3
0,7
Increased ash:
- clay, sandy
37
63
1,9
0,19
2,7
1,5
- lime
40
60
1,6
0,14
16,0
1,2
High ash (lake lime)
26
73
1,2
0,18
34,0
0,8
Silt:
- clay, sandy
12
88
0,6
0,17
4,5
1,3
- lime
13
87
0,6
0,15
15,0
2,3

Classification

Depending on the content of silica (SiO2) and calcium oxide (CaO) sapropels are divided into:

  • organic – with ash content less than 30%;
  • siliceous – with more than 50% silica;
  • calcareous (limey) – with a content of calcium oxide of more than 30%;
  • mixed.

Calcareous sapropels are also used as lime fertilizer, not inferior to chalk and dolomite flour.

According to A.Y. Rubinstein’s classification, sapropels are divided by ash content into:

  • low ash – with ash content up to 30%;
  • medium ash – with ash content 30-50%;
  • increased ash content up to 70%;
  • high ash – with ash content 70-85%;
  • silt – with ash content over 85%.

Sapropel application

According to the generalized data of the All-Russian Institute of Fertilizers and Agrochemistry field experiments, sapropel shows a relatively low efficiency: to obtain crop yield increases comparable to those from manure, sapropel doses should be on average 3 times higher.

Sapropel has some positive properties: high water-holding and low filtration capacity, which improves water-physical properties of light soils. At the expense of adhesive ability sapropel at interaction with soil improves the structure, gives lumpiness, friability, increases air permeability.

Sapropel can be used as an organic fertilizer and in composts with manure, slurry, feces.

The timing of application and methods of laying sapropel under crops does not differ from other organic fertilizers. Sapropel fertilizer is not necessary to embed in the soil immediately after distribution on the field, it is acceptable to make embedding after 3-7 days. Sapropel better suited for sandy and sandy loam soils, as their effectiveness is higher than on soils with heavy granulometric composition.

By its fertilizer value, 1 t of sapropel is equal to 0,6-0,7 t of peat-manure compost. The use of sapropel as a local fertilizer is connected with the costs of its extraction, transportation and application. It is economically justified to transport sapropel to a distance of up to 20 km.

Sapropel is made under crops in the rates which are determined for each field, based on conditions, biological characteristics of crops, agrochemical characteristics of fertilizer. It is best to determine the rates of sapropel by its equivalent content of nutrients, especially nitrogen.

Sapropel is made in doses of 30-40 tons / ha for cereal crops, 50-100 tons / ha – for vegetable crops. It is often used when there is a lack of manure and in the fields, located near the extraction sites.

Sources

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.

Straw

Scientific basis for the use of straw as an organic fertilizer

Straw can be used as an organic fertilizer. For this purpose, it is widely used in foreign and domestic agriculture, in farms specializing in grain production. Scientific prerequisites for the use of straw as an organic fertilizer:

1. Straw is a source of nutrients. The chemical composition of straw varies depending on soil and weather conditions. On average, at 16% moisture content contains: 0.5% nitrogen, 0.25% – phosphorus (P2O5), 0.8-1.0% – potassium (K2O), 35-40% carbon, as well as sulfur, calcium, magnesium, boron, copper, manganese, molybdenum, zinc, cobalt.

At an average cereal yield of 2.0-3.0 t/ha, 10-15 kg of nitrogen, 5-8 kg – phosphorus (P2O5), 18-24 kg of potassium (K2O) return into the soil with straw.

2. Straw serves as energy material for the formation of humus and increase the microbiological activity of the soil. The chemical composition of straw of cereal crops includes a large amount of nitrogen-free substances (cellulose, hemicellulose, lignin) with a small content of nitrogen and mineral elements. The C:N ratio (70-80:1) in straw affects its decomposition in the soil. Straw provides soil microflora with available carbon, but cellulosic microorganisms have a great need for nitrogen, so, given its small amount in the straw, microorganisms consume mineral nitrogen of the soil, i.e. there is a process of nitrogen immobilization. With a lack of nitrogen the processes of straw decomposition are inhibited. For normal decomposition of straw, the ratio C:N should be 20-30:1.

The effectiveness of straw fertilization increases with additional nitrogen application. A comparative evaluation of fertilization with straw with additional nitrogen compensation and manure shows their equal effectiveness. It is important that with the applied straw and nitrogen the C:N ratio is achieved equal to 20:1. For this purpose, when plowing straw, additional 0.5-1.5% nitrogen from its weight, or 5-15 kg N per 1 ton of straw mineral or organic fertilizer.

When composting straw in aerobic conditions, humus yield is 7.9%, with the addition of mineral nitrogen – 8.5% of the mass of the straw. The most intensive humus formation occurs in the first 4 months of composting, during the decomposition of cellulose and hemicellulose. And humus is accumulated in the maximum amount during the period of the highest number of microorganisms.

In combination with mineral fertilizer, liquid manure or legumes used as green manure, straw has the same effect on humus content as an equivalent amount of manure.

3. Straw for fertilizer improves the physical and chemical properties of the soil, reduces nitrogen loss, increases the availability of phosphate and soil biological activity, improves nutrient conditions for plants. The positive effect of straw is possible when favorable conditions for decomposition are created. For example, the rate of microbial decomposition of straw depends on the presence of food sources, their number, species composition and activity, soil type, cultivation, temperature, humidity, aeration. Thus, straw decomposition increases with the addition of nitrogen, phosphorus, manganese, molybdenum, boron, and copper.

The intensity of cellulose decomposition increases from sod-podzolic soils to gray forests and chernozems. Optimal temperature of cellulose decomposition is 28-30 °С with soil moisture content 60-70% of full moisture capacity. The intensity of decomposition in the upper soil layer is higher due to good aeration, large number and diversity of species composition of microorganisms.

Straw increases the nitrogen-fixing capacity and enzymatic activity of the soil.

4. Often in the first year after the application of straw yield of cereal crops decreases due to contained and formed in the decomposition of toxic compounds, as well as a deterioration of nitrogen nutrition of plants.

Of particular importance is straw fertilization for legume crops. The effectiveness of straw increases with the treatment of legume seeds with nitragin, so on areas fertilized with straw, first try to place legume or row crops. Early applied straw stimulates nitrogen-fixing ability of legumes and increases their yield. Nitrogen nutrition of row crops is provided as a result of mobilization of soil nitrogen during inter-row cultivation.

5. Nitrogen from mineral fertilizers reduces the depressing effect of straw on cereal crops. Nitrogen of mineral fertilizers immobilized in the presence of straw is more mobile, less resistant to acid hydrolysis and mineralized faster than nitrogen immobilized without straw, especially humus nitrogen. Subsequently, straw enhances the processes of nitrogen mobilization, increases the use by plants of both immobilized nitrogen and soil nitrogen, which determines the positive effect on the yield of subsequent crops.

Ways to use straw

  1. Chopped and scattered over the field straw is ploughed in autumn during ploughing or in spring in areas with sufficient moisture. This method can be combined with green fertilizer, which eliminates the application of mineral nitrogen fertilizer and also creates favorable conditions for humus formation after plowing.
  2. On soils of heavy granulometric composition and in humid climatic conditions scattered straw is not ploughed in, but is incorporated superficially by disk-tillers, disc harrows or mills. This method of embedding gives a better effect compared with ploughing. Where possible, after superficial embedding, sow an intermediate crop, preferably a legume.
  3. Straw is also used as a mulching material to combat water and wind erosion. Mulching creates favorable conditions for water absorption into the soil, reduces, and sometimes completely eliminates the danger of surface runoff, promotes uniform distribution of water over the soil surface, improves the structure of the arable layer, and reduces moisture evaporation.
  4. Leaving stubble and straw in place of conventional tillage with non-moldboard tillage reduces wind speed over the soil surface by 40-60%, reducing the risk of wind erosion, so in areas prone to wind erosion, non-moldboard tillage is carried out without embedding straw.
  5. On areas fertilized with straw, first of all, it is sought to place leguminous or row crops. When sowing cereal crops on these areas nitrogen fertilizer is applied at the rate of 8-10 kg of nitrogen per 1 ton of straw. Nitrogen brought with straw in the balance of mineral fertilizers is not considered, since it is included in the general turnover of soil nitrogen, and plays a role only with the systematic application of straw for fertilization in the rotation.

Plowing straw into the soil with the addition of nitrogen is more effective in autumn, as the toxic phenolic compounds formed during decomposition for plants during the autumn-winter-spring period are washed out and decomposed from the root layer.

High efficiency of application of straw with addition of nitrogen gives for row crops with long period of vegetation, at its systematic application in crop rotations its efficiency in time increases: the increase of yield of crops of crop rotation from 0,1 t/ha of fodder unit increases to 0,2-0,3 t/ha of each ton of straw.

According to generalized G.E. Merzla results of long-term experiments of the All-Russian Institute of Fertilizers and Agrochemistry, straw when aligned with mineral fertilizers on nutrient elements of application rates, the effect on crop yields and soil fertility is equal to manure. For example, on the powerful low-humus black earth in experiments Drabivska experimental station when aligning the rates of nutrients in the straw and manure for sugar beet yield was 40.8 and 40.5 t/ha, whereas when making only straw in the amount of 4-6 t / ha – 35.7 t / ha, when adding to the straw 90 kg/ha of nitrogen – 37.9 t/ha, in the version without fertilizers – 33.5 t/ha.

In studies of the Sumy experimental station on black earth when applying to corn straw, litter and litter-free manure in equivalent rates of nutrients, green mass yield was 54.5 t/ha; 52.9 t/ha; 53.2 t/ha, respectively, in the control without fertilizers – 41.4 t/ha.

In the experiments of the Krasnodar Research Institute of Agricultural Sciences on leached black earth yield of winter wheat at the application of 5 t/ha of straw was 2.66 t/ha, 5 t/ha of straw and N50 – 3.20 t/ha, in the control without fertilizer – 2.80 t/ha.

On typical micellar-carbonate black earth in the experiments of the Stavropol Research Institute of Agricultural Sciences, the yield of winter wheat in the background was 2.89 t/ha, background + 10 t/ha of straw – 3.00 t/ha, background + 10 t/ha of straw + N20 – 3.13 t/ha.

Systematic application of straw increases its efficiency, and the lack of nitrogen appears only in the first years. In subsequent years, nitrogen is released more than fixed, so the effect of straw is also observed without additional nitrogen application.

Methods of applying and embedding straw

Mineral nitrogen fertilizers can be replaced by litter-free liquid manure at the rate of 6-8 tons per 1 ton of straw. This combination has an effect similar to litter manure.

On the straw, left evenly on the field after combine harvester, you can make a half-liquid, liquid manure, slurry, sewage, or other organic fertilizer at the rate of 15-20 kg/ha of nitrogen with embedding disk-tiller to a depth of 6-8 cm. In this case, its decomposition is accelerated, not accompanied by the accumulation of toxic substances. The main tillage of the soil to a certain depth is carried out in the usual for a particular zone terms.

The effectiveness of using straw for fertilization with the addition of mineral nitrogen or in combination with litter-free manure or green fertilizer is confirmed in many soil and climatic conditions. For example, in Belarus, on typical sod-podzolic, strongly podzolic, light loamy loam and light loamy soils, separate introduction of 3 t/ha of chopped straw and 27 t/ha of liquid manure had the same effect on the crop yield of the crop rotation (potatoes, barley, perennial grasses), as 30 t/ha of litter manure.

Application of straw as fertilizer in the world is much more than in Russia. For example, the proportion of straw in the total amount of organic fertilizer in Germany is now: for sugar beet – 72%, under wheat – 71%, under winter barley – 58%, whereas at the beginning of 70-ies this figure did not exceed 15-25%.

Sources

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.

Peat

The area of peatlands in Russia is over 80 million hectares, the total reserves of peat on air-dry matter amount to 160 billion tons, which is equal to more than 1/2-2/3 of the world reserves. 

Peat reserves in Russia are distributed as follows: about 70% are located in the West Siberian region, 13% in the Northwest region, 6% in the Urals, and 3-4% each in the Far Eastern, Central and East Siberian regions. 50.6% of the deposits are represented by high-moor peat, 31.1% by low-moor peat, and the rest by transitional peat.

Types of peat are unequal in quality, so the ways of its use as a fertilizer are different. All peat bogs and extracted peat are divided into highland, lowland and transitional peat. Depending on the degree of peat decomposition, determined by the content of humified substances, peat is distinguished:

  • slightly decomposed – degree of decomposition 5-25%;
  • medium-decomposed – 25-40%;
  • highly decomposed – more than 40%.

Types of peats

The type of peat is determined by the location of the bog in terms of relief elements and the composition of vegetation.

The high-moor type is formed on elevated elements of the relief from white sphagnum mosses with small amounts of moss-grass, Ledum, blueberry, cranberry and other plants undemanding for nutritional elements. Sphagnum top peat is the most poor in elements, very acidic, low-humic (up to 20%), low ash, the most moisture- and gas-intensive, contains up to 40% hemicellulose and cellulose. It is the best litter material for animals and a component of composts.

The lowland (low-moor) type is formed under the influence of groundwater with high mineral content in the depressions of the relief with sedges, reeds, reeds, horsetails, green hypnum mosses, alder, willow, birch and other moisture-loving and more demanding to nutrients plants.

Lowland peat is the remnants of herbaceous and woody vegetation, contains more nutrients, is less acidic, highly ashy, contains up to 50% of humic substances, is highly humic, enriched with lime and phosphorus. When drained it is suitable for cultivation of vegetable, fodder and other crops, can be used as an organic fertilizer in the open and closed ground, for the preparation of pots and as a component of composts.

Transitional type is intermediate between the high-moor and low-moor types. And the lower layers of transitional peat are usually closer to the lowland, the upper ones to the high-moor.

The type of peat is determined by low-decomposed residues of plants – peat formers, which content is more than 20% of the dry matter mass.

Composition and properties of peats

The botanical composition, degree of decomposition, ash content, nutrient content, acidity, moisture capacity and cationic absorption capacity (CAC) are important for agrochemical assessment of peat quality. Botanical composition determines the ash content, acidity, degree of humification, provision with nutrients.

The degree of decomposition is an indicator of the agronomic use of peat. Weakly decomposed peat is used mainly for animal bedding, medium-decomposed peat after extraction and ventilation is used as fertilizer, for compost preparation or for cultivation of crops after hydromelioration of peatlands.

Ash content of peats can be normal, i.e. up to 12%, and high – more than 12%. High ash content, as a rule, lowland peats (20-30%) are obtained in the presence of sand, clay, increased quantities of lime (peat-tuff) or vivianite in them. Increased ash content at the expense of calcium and phosphorus (vivianite) increases the value of peat. Peat turf and vivianite peat without composting is used as a direct fertilizer as well as for the liming of acidic soils and for phosphoritization.

Table. Agrochemical indicators, % on the absolute dry weight of different types of peat[1] Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodin. - Moscow: Kolos, 2002. - 584 p.: ill.

Type of peat
Ash
рН
Organic matter
N
P2O5
K2O
CaO
pH of the salt extract[1]
Hг
T
H2O
KCl
mg⋅eq/100 g dry weight
Lowland peat
8-15
5,5-7,0
4,8-5,8
85-92
2,5-3,5 (2,3-3,3)
0,2-0,6 (0,12-0,5)
0,15-0,20 (< 0,15)
2,0-6,0
4,7-5,5
70-80
160-250
Transitional peat
5-8
4,0-6,0
3,5-4,8
90-95
1,2-2,5 (1,0-2,3)
0,10-0,25 (0,1-0,2)
< 0,15 (0,1)
0,2-0,4
3,5-4,7
-
-
Highland peat
< 5
3,0-4,5
2,6-3,2
95-98
0,7-1,5 (0,8-1,2)
< 0,15 (0,06-0,12)
< 0,10
< 0,4
2,8-3,5
120-180
100-200

Nitrogen contained in peat is in organic compounds that are poorly absorbed by plants. Therefore, the use of peat in its pure form is ineffective. The costs of extracting and using peat in its pure form are often not repaid by an increase in yield.

The content of nutrients decreases in the transition from lowland to highland peat. Peat contains most of the nitrogen, and most of it is contained in the organic form and becomes available to plants only after mineralization, which in acidic environments almost does not proceed, but can be accelerated after neutralization and at composting with manure, slurry, poultry manure, feces.

The content of phosphorus in peats is small, with 2/3 soluble in weak acids and available to plants.

Potassium content in peat is the least, and only half of the gross content is available for plants, of trace elements – the least of all copper. Therefore, when cultivating crops on drained peatlands, they are fertilized with potassium and copper fertilizers.

The acidity of peat is an indicator of the type and methods of its application. When the acidity is less than 5.5 lowland decomposed peat is not suitable for use as a fertilizer without prior composting with lime, phosphate flour, ash, manure, slurry. All peats can, when composted with phosphate flour, convert phosphorus into forms available to plants.

Raw peat contains 80-90% water. With one ton of such peat 100-200 kg of dry organic matter is applied. Raw peat does not allow quality uniform application to the field. Too dry peat is also inexpedient to use, as it has a high absorption capacity. Peat with moisture content of 35-40% absorbs moisture of the soil layer, which leads to soil drying and causes moisture deficiency. In the dry arable layer the speed of decomposition of peat is very slow.

The absorption capacity is important when peats are used as bedding material for birds and animals, due to the absorption of moisture and gases, in particular ammonia. The maximum moisture absorption capacity of upland peats is 1000-1800% on the dry mass, and gradually decreases in the transition to lowland peats, remaining at 500-1000%. The absorption capacity of all types of peats is higher than that of heavy chernozem. It is also important for the storage in peats in the absence of storage facilities of significant amounts of liquid ammonia of industrial production and local preparation of peat-ammonia fertilizers (PAF).

Application of peat and peatlands

Peat is used:

  • for litter for livestock and poultry;
  • as a component of composts;
  • for the preparation of peat-mulch pots and cubes;
  • as a mulching material;
  • substrate for cultivation of crops in an indoor environment;
  • as organic fertilizer.

Upper sphagnum peat with degree of decomposition up to 25%, ash content up to 10-15%, moisture content of 50%, content of wood particles up to 6 cm in size up to 10% is used primarily as litter. Gypne, sedge and reed types of peat for these purposes are used rarely and only in slightly decomposed (up to 20%) state.

As a direct fertilizer, lowland peat rich in lime or phosphorus is used, mainly on light soils, with pH over 5.5, ash content over 10%, including СаО over 4% and the degree of decomposition over 40-50%. Doses of pure peat 50-100 t/ha can be reduced by its combined introduction with slurry (5-10 t/ha), semi-liquid manure, faeces, poultry manure. Rates of peat-tuffs are determined by the content of CaO, vivianite peats – by the content of P2O5.

Surface aerated lowland and transitional peats with a layer of up to 5 cm in the inter-row plantings of berry, fruit and vegetable crops are used as mulching material. Mulching contributes to improvement of water, air, heat and nutrient regimes in the upper soil layer, suppresses growth and development of weeds and formation of soil crust.

The use of peatlands after drainage for cultivation of agricultural crops is possible without and after removal of the top peat layer, but in the latter case the thickness of the peat layer should be at least 50 cm.

Peat soils need liming.

Since peat soils are poor in phosphorus, potassium and copper, mineral fertilizers are applied when cultivating crops. On the newly developed peatlands and nitrogen fertilizers are effective, and on the developed after 8-10 years, they often lose effectiveness. Since peatlands are poor in microflora, the newly developed to accelerate the decomposition of organic matter is advisable to make a small doses of fertilizers rich in microflora, such as feces, poultry manure, manure, slurry, bacterial preparations. Rates of macro- and microfertilizers are established taking into account the needs of crops and planned yields.

Application of peat for composting

To increase the availability of peat nitrogen for plants, it is composted with biologically active components or used for livestock litter.

Composts are placed in round piles 3-4 m in diameter at the base, 1-2 m at the top and up to 1.5 m high, or in stacks 1.5-2 m wide, 1 m high and 1 m long – depending on the amount of material. Loose materials are tamped down, covered with soil, straw or peat, to prevent drying out.

In all composts any peat is the most valuable component, but it is better with a higher degree of decomposition (more than 20%), ash content up to 25% and the content of wood inclusions up to 10%, and with lime, ash and phosphate flour – with a pH less than 5 and ash content less than 10%.

To make seedling cubes and pots to peat add compost, humus, poultry manure, silt, sod soil, mineral fertilizers, lime or ash. For this purpose, lowland and transitional peat with a neutral or weakly acidic reaction, the degree of decomposition of 30-40% and ash content up to 15% are better suited.

Peat-manure composts

When composting peat with manure, excessive acidity of peat is eliminated, conditions for the course of biological processes are created, decomposition of peat is accelerated, the amount of mobile nitrogen available to plants increases. Microbiological processes proceed faster if the temperature rises to 60-65 ° during composting in the stack, so unlike manure, stacks of peat-manure composts are not recommended to compact. Composting peat with manure also contributes, due to its high absorption capacity, to the preservation of ammonia of manure.

Peat-manure composts are prepared in the field, at the place of application, less often near livestock buildings or in manure storages. For one weight part of manure in winter time take 1 part of peat; in spring-summer harvesting – 1-2 parts. All types of peat, the humidity of which is no more than 60%, are suitable for the preparation of peat-manure composts.

Adding phosphate meal to peat-manure compost is recommended in an amount of 2-3% of the mass of the compost. If the compost is prepared for application to potatoes on light soils, potash fertiliser in an amount of 0.5% of the mass of the compost must also be added, provided it is well mixed and then evenly spread in the field.

Preparation of peat-manure compost is carried out by different methods.

The layered method can be used at any time of the year. To do this, unload the peat at the site and bulldoze it with a layer of 40-50 cm. Manure is taken out onto the peat and leveled out by a layer of 25-30 cm. The subsequent layering of peat and manure in stacks is done by loaders. The stack is completed with a layer of peat with a thickness of 40-50 cm. The finished stack has a width at the base of 3-4 m, a height of 2 m, any length. In winter, to avoid freezing of manure, stacking is carried out within 1-2 days.

Focal method of stacking differs from layer-by-layer method in that the manure is placed on the peat cushion in separate piles at a distance of 1 m from each other, the gaps between them are filled with peat. Laying is carried out by the same machines. The focal method of composting provides a better warming of the compost in winter.

The site method consists in creating a peat cushion with a layer of 25-30 cm, followed by laying and leveling the manure. Then there is 2-3 times discing with a heavy disc harrow to mix the manure with peat, the mixture is raked by bulldozer into stacks for composting. This method is more suitable for composting in the spring-summer and autumn periods.

Properly prepared peat-manure composts have the same effect as manure.

Peat-slurry and peat-fecal composts

To preserve the nutrients of slurry and feces, and to increase the fertilizing effect of peat, peat-slurry and peat-fecal composts are prepared. It is better to prepare them in spring and summer. To do this, the peat is placed in two continuous adjacent rolls so that between them formed a trough-shaped depression. The thickness of the layers at the contact points of the shafts should be 40-50 cm. End walls are made manually or by bulldozer. Slurry or feces is poured into this pit from a tanker or a slurry spreader. The liquid should not overflow or leak through the side walls of the pit. After the slurry or faeces have been absorbed by the peat, the mass is raked into stacks without compaction.

Per 1 ton of peat, depending on the type and moisture content, 0.5-1 tons of slurry or faeces are taken. As a rule, fecal matter contains 1.5 times more nitrogen than manure. Phosphate meal should be added to the peat-slurry compost in an amount of 1.5-2% of the mass of the compost. All types of peat, except carbonate peat with a high lime content, are used for the preparation of peat-slurry and peat-fecal composts. They are prepared more often in the field at the place of application. Peat-slurry composts in the spring and summer mature within 1-1.5 months.

Such composts are also prepared on drained peatlands, near the location of sources of faeces and fertilized field.

For this purpose, directly on the peat field after drying peat crumbs in layers-surface method rake in swaths, make feces at a ratio of 1:1. If there is a shortage of faecal matter, 3-5 tons of lowland peat per 1 ton, but this compost is less concentrated, and its doses of making twice as much. The compost is suitable for use after a few months, and it has a homogeneous appearance, easily crumbling.

During the preparation of peat-fecal compost temperature must rise to 55-60 °C, in order to under the influence of high temperature to destroy the eggs helminths and pathogens. If the temperature in the toro-fecal compost does not rise to 55-60 °C, you can use it for potatoes and vegetable crops only in the second year after putting it in.

As a rule, peat-fecal and peat-slurry composts are not inferior to manure in terms of efficiency. They have the best effect on the harvest in combination with mineral fertilizers. Under cereals as a basic fertilizer contribute 10-15 t/ha of peat compost, under potatoes, silage and other forage crops – 20-25 t/ha, vegetable crops – 30-40 t/ha.

In the absence of peat, faeces can be composted with soil. To do this, lay faeces and dry soil in layers at a ratio of 1:1.

Sources

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.

Poultry manure

Chemical composition of poultry manure

The nutrient content of poultry manure depends on the composition and quality of the feed and, to a lesser extent, on housing methods.

Table. Chemical composition of poultry manure, %[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

Poultry manure
H2O
N
P2O5
K2O
CaO
MgO
SO3
Chicken
56
1,6
1,5
0,8
2,4
0,7
0,4
Duck
70
0,7
0,9
0,6
1,1
0,2
0,3
Goose
76
0,5
0,5
0,9
0,8
0,2
0,1

Poultry manure contains trace elements: 100 g of dry matter contains 15-38 mg of manganese, 12-39 mg of zinc, 1-1.2 mg of cobalt, 1-2.5 mg of copper, 300-400 mg of iron. Most of the nutrients in poultry manure are in water-soluble form.

Poultry manure production

Chicken manure surpasses manure in its fertilizing qualities and is not inferior to mineral fertilizers in speed of action. Geese (goose) and duck droppings contain more moisture and are close to manure in terms of nutrient content. During the year, from 100 hens collect 600-800 kg of manure, from ducks – 700-900 kg, from geese 1000-1200 kg.

Drying of poultry manure after 8 hours of cage housing is 10-12%, after 12 hours – 13-16%, after one day – 27-32%. Floor housing produces litter manure that dries faster and reaches 50% in 12 hours and 35% under ducks and geese.

Litter chicken manure

Litter chicken manure has sufficient bulkiness, low moisture content. It is used as litter manure in doses calculated by nitrogen. With a moisture content of 56%, it contains on average 1.6% N, 1.5% P2O5 and 0.9% K2O. Peat, chopped straw, and sawdust of deciduous trees laid in a layer of 30-40 cm as litter is used; the upper layer is mixed with the lower one as it gets soiled. Litter is removed when livestock changes 2-3 times a year. Another option is to use litter: peat is placed in a 5-10 cm layer, which is added 15-20 grams per 1 head when polluted. When the height of litter reaches 0.5-1.0 m, it is removed.

The moisture content of peat should be no more than 50%, other types of litter – 30%. Litter promotes preservation of litter nutrients and reduces their loss. Deep litter application in poultry houses is the most reliable method for preserving nitrogen, improving physical properties of litter, reducing labor costs and increasing productivity. The best material for deep litter is dry shredded sphagnum peat with the addition of shredded straw. Dry peat crumbs of lowland peat, straw, chaff, and sawdust can also be used for litter. 

Moisture content of poultry litter manure varies from 30 to 50%. The best quality is poultry manure fertilizer based on peat and straw.

Table. Composition of different types of poultry litter manure at 40th moisture content (% on crude matter)[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

Type of litter
N
P2O5
K2O
Peat
2,22
2,00
0,78
Sawdust
1,60
1,40
0,62
Peat and straw
2,15
1,65
0,68
Straw
2,10
1,60
0,85

Nitrogen losses from poultry manure can be reduced by adding superphosphate in an amount of 6-10% of the weight of raw manure. Superphosphate is added after removing it from the poultry house. Concentrated fertilizer thus obtained is applied under row crops and vegetable crops at 4-5 t/ha, under cereals – 2-2.5 t/ha.

Litter-free chicken manure

Litter-free chicken manure is a sticky, smeary mass of stinky odor with a higher nutrient content than litter chicken manure. It also contains weed seeds, helminth eggs and larvae, flies, and microorganisms, many of which are pathogens.

All nutrients in poultry manure are contained in plant-available forms. Nitrogen of uric and hippuric acids undergoes ammonification, which is accompanied by its losses during improper storage, which can reach 50% of total content in 6 months. To reduce nitrogen losses during accumulation and storage of litter-free chicken manure, 20-40% of the weight of peat crumbs or composted with peat, in the absence of peat – up to 30% of soil is added to it.

At poultry farms for decontamination, deodorization, preservation of nutrients, improvement of physical and mechanical properties of litter-free manure use rapid thermal drying at 600-800 °C. One ton of raw manure yields 300-350 kg of granulated or powdered concentrated organic fertilizer with 15-20% moisture content; nitrogen loss does not exceed 5%; the concentration of nutrients increases by 3 times: 4-6% N, 3-4% P2O5 and 1.5-2.0% K2O, CaO – 4.5, MgO – 1.6%.

Thermally dried chicken manure is decontaminated and biologically inactive material suitable for long-term storage. Drying manure is associated with high energy costs and is used only at poultry farms located near cities or recreation areas, where it is impossible to dispose of manure by other means.

Dry poultry manure

Dry poultry manure – loose organic fertilizer, more transportable, can be stored in a dry place, for 6 months of storage in bags or open stacks loses 4-11% organic matter and 3-8% nitrogen.

Composting poultry manure

There are no volatile forms of nitrogen in fresh chicken manure, but during storage in piles it heats up a lot and nitrogen is lost due to the conversion of uric acid into ammonia compounds. Losses during such storage in 1.5-2 months can reach 30-60% of the total content. Losses are eliminated by composting fresh poultry manure with peat, humus, straw, sawdust, turf or topsoil.

Composting is a method of manure utilization, increases the yield of fertilizer, and is more environmentally friendly. Peat-manure composts are the most common. To obtain high quality compost balanced in terms of nutrients, reducing nitrogen losses, increasing biological activity, it is recommended to add 10-20 kg of powdered superphosphate, 20-30 kg of phosphate meal or 5-10% of the compost mass of phosphogypsum per 1 ton of compost mass. The addition of 1.5-2% potassium chloride protects the piles from freezing in winter.

For fast and optimal processes in the compost mixture should have a moisture content of 65-70%, the ratio of C:N of 20:1 to 30:1, acidity pH 6-8. Stacking is done when the temperature drops to 30-35°C. Compost is considered mature when the temperature in the stack does not increase after turning. The composting process takes 1-2 months. Since manure is primarily a nitrogen-phosphorus fertilizer, its use necessitates an additional application of potash fertilizer.

Applications

Poultry manure is characterized by high stickiness, which makes it difficult to apply to the soil with existing machinery. The suspended solids contained in the manure runoff prevent its application by sprinkler systems as well. For economic reasons, the transportation radius of liquid manure is limited to 5 km, so it is advisable to use litter poultry manure, composted manure, and in some cases dry manure as fertilizer.

Poultry manure fertilizers are applied first to row crops, then to winter crops and grasses as the main fertilizer and top dressing. In areas with sufficient moisture, manure and its compost are embedded with disc-shaped tools and cultivators; plowing of compost is more effective on sandy and sandy loam soils. Embedding of organic fertilizers, including poultry manure compost, is carried out by tiered plows such as ПЯ-3-35 with a single fertilizer application for a number of years of crop rotation.

Poultry manure is used before sowing crops and during the growing season as an additional fertilizer. When applying poultry manure before sowing, depending on the type, productivity of crops and state of soil cultivation, it is applied in doses: litter-free – 5-10 t/ha, littered – 10-20 t/ha, heat-dried – 2-4 t/ha. When feeding by solid method the doses of litter-free manure are 0.8-1 t/ha, when applied locally in furrows and holes – 400-500 kg/ha, doses of litter manure are increased by 20-30%, dry manure – reduced by 3 times.

Poultry manure composts are comparable with litter manure in efficiency and in some cases surpass it.

All types of poultry manure when applied in doses equivalent to mineral fertilizers are not inferior in effect and aftereffect on the yield of crops. Under crops sensitive to increased concentration of soil solution and responding positively to improved air carbon dioxide nutrition are superior to mineral fertilizers.

Table. Approximate rates for the application of litter poultry fertilizers for agricultural crops on black soils and gray forest soils of the forest-steppe zone (according to research institutions, t/ha)

Crop
Poultry manure
Compost
dry
natural moisture
litter
liquid
Cereals
2-5
5-7
6-8
20-25
10-15
Potatoes
2-4
7-12
10-15
-
20-25
Corn for grain and silage
6-10
7-12
10-15
60-80
20-25
Sugar beet
5-8
7-12
10-15
50-60
20-25
Forage root crops
5-8
7-12
10-15
50-60
20-25
Technical crop
5-8
10-12
12-15
-
20-25
Vegetables
5-8
10-12
10-15
30-40
30-40
Annual grasses for green fodder
-
5-8
8-10
23-25
10-15
Perennial grasses for green fodder and hay
-
-
-
15-20
-
Meadows and pastures
-
-
-
20-30
-
Bare fallow
-
5-8
7-10
30-40
15-20

Table. Approximate rates of poultry manure fertilizers for crops on sod-podzolic soils of the Non-Black Soil zone (according to research institutions, t/ha)

Crop
Poultry manure
Компост
dry
natural moisture
litter
liquid
Winter cereals
3-4
13-15
10-15
45-50
20-25
Spring cereals
3
8-10
10-15
20-25
20-25
Potatoes
4-5
15-20
20-25
60-70
40-50
Corn for silage
4-5
15-20
15-20
60-70
40-60
Forage root crops
4-5
15-20
15-20
60-70
30-50
Forage cabbage
4-5
15-20
15-20
60-70
40-60
Vegetables
6-8
20-25
20-25
60-70
40-60
Annual grasses
-
-
13-15
50
20-30
Perennial grasses
5-8
10-15
-
30
-
Hayfields and pastures
-
15-20
-
30-40
-

Sources

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.

Slurry

Slurry is an organic fertilizer, represented by fermented animal urine flowing into slurry collectors (tanks) of livestock buildings and manure storages. On average 10-15% of the weight of fresh manure, but varies depending on how it is stored. If there is sufficient peat litter, slurry usually does not accumulate.

According to the All-Russian Institute of Fertilizers and Agrochemistry, from 10 tons of fresh litter manure for 4 months leaves a dense method of storage of 170 liters of slurry, loose-dense – 450 liters, loose – 1000 liters, that is, the faster decomposition of manure, the more slurry is released.

Composition

The content of nutrients in the slurry varies. On average, it contains 0.25-0.30% N, 0.4-0.5% K2O and 0.01-0.06% P2O5. In terms of efficiency is not inferior to equivalent doses of mineral fertilizers. The content of nutrients varies depending on the rations and types of animals, methods of accumulation and storage of slurry: from 0.01% to 1.0% of nitrogen, from 0.05% to 1.2% of K2O.

Table. Content of nutrients in the slurry[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

Slurry samples from slurry tanks
Number of samples
Average content, %
of nitrogen (N)
of potassium (K2O)
of phosphorus (P2O5)
On dairy farms
63
0,26
0,38
0,12
On pig farms
12
0,31
0,36
0,06
At the stables
18
0,39
0,58
0,08

The main nitrogenous substances in slurry are urea, uric acid and hypuric acid, which are converted by urobacteria into carbon dioxide ammonium, which breaks down into carbon dioxide, ammonia and water. Uric acid turns into urea, the latter into carbonic ammonia:

CO(NH2)2 + H2O → (NH4)2CO3.

Collection and storage

Ammonia, which is formed by the decomposition of ammonium carbonate, causes nitrogen losses from the slurry. To reduce nitrogen losses, we use sufficient litter, add 3-5% of the slurry weight of superphosphate, and arrange sewage in livestock yards so that urine is not retained in the gutters. Slurry tanks are periodically cleaned of sludge so that the slurry tanker receives settled slurry. Slurry tanks should be tightly closed to prevent ammonia losses.

In barns without slurry tanks, the slurry drains are filled with peat, replacing it every time after the slurry is saturated. During the stable period (220-240 days) about 2 tons of slop is collected from each cow or 10-12 calves.

Applications

Slurry can be used all year round: for preparing composts, fertilizing winter crops, fertilizing row crops, and applying it for autumn plowing. You can prepare compost from the warm days of March until the fall.

The slurry can be applied as such before sowing and in top dressing with rapid incorporation into the soil, and in composts before sowing of crops. Rates of pre-sowing application vary from 20 to 50 tons/ha depending on the quality of slurry, the needs of fertilized crops and soil fertility. For perennial grasses fertilization in crop rotations, in meadows and pastures, 10-30 t/ha is applied; 8-15 t/ha is applied to intercrops of row crops.

For feeding of winter crops, meadows and pastures, 3-5 tons of slurry diluted by 2-3 times with water are applied. This method allows to distribute slurry evenly over the area, reduces nitrogen losses, and prevents burning of plants. If the slurry is diluted with water during accumulation, and its nitrogen content does not exceed 0.2-0.25%, it is not recommended to dilute it before surface feeding. Winter crops should be harrowed after feeding. Delayed harrowing leads to ammonia losses and reduced efficiency. When feeding vegetable and row crops, the slurry is introduced with the help of tanks with fertilizer device ПРЖ-1,7 which ensures introduction at a specified depth and without nitrogen losses. Dilution with water is not required at this method of application.

For the first feeding of row crops, slurry is introduced beside the row in the dosage of 5-7 tons/ha, for the second – in the middle of the row in the dosage of 8-12 tons/ha.

As a basic fertilizer it is applied in a dose of 10-20 t/ha depending on the needs and peculiarities of the crop. Slurry is immediately ploughed in to avoid loss of nitrogen in the arable land.

One ton of slurry when properly used increases the yield of crops by 100 kg/ha in grain units, and with the addition of superphosphate increases its effectiveness (due to the low content of phosphorus in the slurry). The maximum effect is achieved when composted with peat or other organic components.

Sources

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.