Litter Manure

Composition

The composition of litter manure includes solid and liquid animal excreta and litter. Excreta contain about 40–50% of the organic matter and nitrogen, 60–70% of the phosphorus and potassium of their initial content in feed.

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

In horses, sheep, and cattle, solid excreta exceed those in pigs. Solid and liquid excreta are not equivalent in composition or fertilizing value: more than 95% of phosphorus is contained in solid excreta, from 50 to 75% of nitrogen and more than 80–90% of potassium in liquid excreta. In animal excreta, the content of dry matter averages about half of the dry matter of feeds, while the content of nitrogen and ash elements may be 1.5–2.0 times higher than in feeds.

When concentrated feeds, whose digestibility is higher than that of hay, are introduced into animal rations, the excreta will contain less dry matter, and the content of nitrogen and phosphorus will be higher.

In the excreta of cattle and pigs, the content of dry matter and nutrients is lower than in horses and sheep. Therefore, the excreta of sheep and horses decompose faster and release much heat during storage, and the manure of these animals is called hot, while that of pigs and cattle is called cold. Hot manure is used for filling hotbeds, constructing warmed beds, and as biofuel.

The quality of manure depends on the conditions and duration of storage: during long storage, the relative content of nitrogen, phosphorus, and potassium increases as a result of decomposition of organic matter. Because the chemical composition of manure changes, to correctly determine the dose it is desirable to determine its chemical composition before application. Otherwise, reference data are used.

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

Solid excreta are rich in microorganisms: up to 30% of the total mass; liquid excreta at the moment of excretion may contain none at all, but, when mixed with solid excreta, they quickly become enriched with microorganisms present in the medium.

The quality of manure and its chemical composition depend on the type of feeds, ration, animal species, amount and type of litter, and storage method. Thus, when animals are fattened with a large amount of concentrated feeds in the ration, the manure is characterized by a high content of nutrients compared with manure from animals receiving silage, root crops, and roughages with a high fiber content. About 40% of organic matter, 50% of nitrogen, 80% of phosphorus, and 25% of potassium pass from consumed feed into manure.

Litter

The quality of manure depends on the chemical composition and absorption capacity of the litter, which favors the creation of conditions for the vital activity of microorganisms and the decomposition of feces. The ability of the litter to absorb liquids and gases is important. The quality of manure largely depends on the content of nitrogen and ash substances in the litter. The highest nitrogen content is characteristic of peat litter and legume straw, the latter also containing the greatest amount of phosphorus.

The best litter material is high-moor peat. It is distinguished by low ash content (1.5–3%) and a high ability to absorb liquids and gases: 1 kg of high-moor peat can absorb 9–18 kg of water and 15–30 g of ammonia, whereas 1 kg of straw absorbs 2–3 kg of water and 2–5 g of ammonia. The use of peat litter in cattle yards reduces the concentration of ammonia and carbon dioxide in the air by 2.5 times and reduces the relative humidity of the room from 100 to 75%. Peat litter improves the zootechnical conditions for keeping livestock and increases manure yield and reduces nitrogen losses. When litter is increased to 8–10 kg per day, manure yield increases and nitrogen losses are reduced to zero; 1 t of dry peat litter gives an additional 5–7 t of manure with a high nitrogen content.

Straw for litter is best used in chopped form up to 10–15 cm, since this promotes better absorption of urine, uniformity of manure, its uniform distribution over the field, and plowing-in. The effectiveness of manure on chopped straw litter is 20–30% higher than that of manure on whole-straw litter. When there is a shortage of straw and high-moor (sphagnum) peat, dry peat crumbs of transitional or low-moor peat with a degree of decomposition of no more than 25% and moisture no more than 40–45% are used as litter.

When sawdust is used as litter, the manure is of low quality with a low nitrogen content but a high content of slowly decomposing fiber. Such manure is better suited as biofuel in protected-ground vegetable growing, and the following year for field crops.

Litter is part of manure, increasing its amount, and, depending on type and amount, affects the chemical composition and losses of nutrients. Litter absorbs liquid animal excreta and the ammonia formed during urine decomposition, reducing losses of nitrogen, potassium, and other soluble substances and gases. Litter reduces the moisture of excreta, making them looser, which promotes their microbiological decomposition and facilitates loading, transportation, application, and incorporation.

Litter materials differ in nutrient content and absorption capacity.

Peat and straw have the maximum absorption capacity, and peat contains more nitrogen than the straw of cereal crops. Manure on straw litter is called straw manure, and on peat litter, peat manure.

When peat and straw are insufficient (or absent), and also for sanitary-hygienic and economic reasons, leaves and sawdust may be used as litter. The quality of manure then deteriorates: the content of fiber and lignin increases, and with sawdust the nitrogen content additionally decreases. Such manure decomposes more slowly and is less effective in the first year after application.

The best litter is high-moor peat with a degree of decomposition up to 25–30% and moisture of 30–40%. More decomposed and moist peat absorbs less liquid excreta; drier peat absorbs poorly and becomes wet slowly. The advantage of high-moor peat over transitional and low-moor peat is also due to its more acidic reaction, which suppresses pathogenic microorganisms (causative agents of anthrax, brucellosis, paratyphoid, and Escherichia coli).

Average daily rates (norms) of litter materials per 1 head of livestock depend on the animal species, amount and quality of consumed feeds, and material and technical capabilities.

With an increase in succulent feeds in animal rations, for example green mass, root crops, and silage, the amount of litter is increased; with an increase in the share of concentrated feeds, it is reduced. The amount of manure depends on the animal species, duration of the stalling period, amount and quality of feeds and litter materials, and the time and methods of manure storage.

Calculation of Litter Manure Yield

The amount of manure accumulated on a farm is determined by the livestock population, duration of the stalling period, amount of litter and feeds. Low manure yield is often associated with low use of litter and poorly organized collection and storage of manure. The use of straw for litter leads to an increase in manure accumulation, improvement of its quality, and improvement of zoohygienic conditions for keeping animals. With abundant feeding of cows with an average annual milk yield of 4000–4500 kg, the manure yield with daily use of 20 kg of low-moor peat as litter is 11–12 t per cow per year.

During a stalling period of 200 days, according to data from VNIIUA, from 1 head of cattle with a daily litter rate of 2 kg, 7 t of straw manure and 8 t of peat manure are obtained. At the same time, nitrogen losses over 3.5 months of storage from the first were 44%, and from the second 25%. With an increase in daily litter norms to 4 kg over the same period, the yield of straw manure was 8 t, peat manure 9 t, and nitrogen losses during storage from the first were 31%, from the second 14%. An increase in daily litter norms to 6 kg increased the yield of straw manure to 9 t, peat manure to 10 t, and reduced nitrogen losses during storage from the first to 13%, from the second to 3%.

The amount of manure decreases with a shorter stalling period.

The total yield of fresh manure on a farm is approximately determined from the table data with subsequent recalculation for the livestock population.

The manure yield H can be calculated using the Wolff formula:

where

K/2

— half of the dry matter of feeds transferred into manure;

P

— dry mass of litter;

4

— coefficient showing that the water content in manure is 4 times greater than in the dry matter of feeds and litter.

There are also other methods for calculating manure yield. Thus, in France, the amount of manure is determined by multiplying the mass of the herd by a coefficient of 25.

The amount of manure changes depending on the methods and duration of storage. With loose stacking, manure loses 33–50% of dry matter after 3–4 months; with compact storage, only up to 10%. The bulk density of manure also changes depending on the method of stacking and degree of decomposition: without compaction, the fresh mass of 1 m³ is 300–400 kg; in a compacted state, 700 kg/m³; semi-rotted manure, 800 kg/m³; and strongly decomposed manure, 900 kg/m³.

Manure Storage Periods

Depending on the periods and conditions of storage and the degree of decomposition of organic components, manure acquires a corresponding appearance and consistency.

According to storage periods, four stages of decomposition of straw manure are distinguished: fresh, semi-rotted, rotted, and humus.

Fresh, or weakly decomposed, manure: straw changes insignificantly in color and strength.

Semi-rotted manure: straw acquires a dark brown color, loses strength, and tears easily. Due to decomposition, manure loses 10–30% (on average 25%) of weight and dry organic matter.

Rotted manure: a homogeneous mass; decomposition of straw reaches a state in which individual straws cannot be detected. Weight losses from decomposition reach 50% of weight and dry organic matter.

Humus: a loose dark mass; losses from decomposition amount to up to 75% of the initial weight and dry organic matter.

Manure is not brought to the rotted state or humus, because with prolonged decomposition the amount of organic matter decreases by 2–3 times, while the percentage content of nitrogen and phosphorus increases significantly less.

For plowing-in, semi-rotted litter manure is best.

Manure Storage Methods

Depending on the methods of accumulation and storage of manure before application to the soil, the processes of decomposition of organic substances and the extent of nutrient losses differ.

The following manure storage methods exist:

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

Loose (Hot) Storage

Loose, or hot, storage is rarely used, as it is accompanied by large losses of nitrogen, organic matter, and slurry. The poor quality of manure with such storage is associated with uneven decomposition: usually inside the heaps it decomposes strongly, while along the edges it dries out and remains poorly decomposed.

Biochemical Processes Occurring During Manure Storage

During manure storage, numerous biochemical processes occur in it under the action of microorganisms. Liquid animal excreta contain easily mineralizable nitrogenous compounds: urea, hippuric and uric acids, the decomposition rate of which decreases from the first to the last.

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

then into ammonia, carbon dioxide, and water:

Hippuric acid decomposes into benzoic and aminoacetic acids:

the latter into hydroxyacetic or acetic acid and ammonia:

Uric acid, often already in the body of mammals, decomposes with the release of carbon dioxide and allantoin (glyoxyldiureide):

the latter decomposes with the formation of glyoxylic acid and urea:

Urea according to the previously described scheme.

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

Nitrogenous compounds of solid animal excreta and litter undergo ammonification, but much more slowly because of the fiber and easily decomposable carbohydrates (pectin, pentosans, starch, sugars) contained, which serve as energy material for microorganisms. The coarser the animal feeds and the more straw contained, the more easily decomposable nitrogen-free compounds and fiber, and accordingly the greater the amount of nitrogen fixed by microorganisms.

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

under anaerobic conditions, into carbon dioxide and methane:

The fiber content in manure can reach 30–36% calculated on dry matter, and pentosans 14–16%, which decompose during manure storage. With loose storage of manure, fiber decomposes by half; with compact storage, insignificantly. During manure decomposition, butyric, acetic, and other organic acids are also formed.

The rate of decomposition of organic substances in manure depends on moisture, temperature, oxygen access, i.e., degree of aeration, and chemical composition of the manure. The higher the aeration, the faster and at a higher temperature decomposition occurs. A greater content of easily decomposable organic substances promotes faster fermentation processes.

Nitrification and denitrification of nitrogen do not occur in manure, since nitrifying bacteria die under aerobic conditions at high temperatures and cannot exist under anaerobic conditions. High concentrations of ammonia and increased content of soluble organic compounds are also destructive to them. In the absence of nitrates, denitrification does not occur.

Nutrient Losses During Manure Storage

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

Potassium in manure is almost not lost during storage. Thus, with loose storage, 85% was in water-soluble form; with mixed storage, 91%; with compact storage, 93% of the initial content in fresh manure. During decomposition in soil, potassium is consumed in small amounts by microorganisms and remains in compounds available to plants. Calcium and magnesium are bound by acids formed during the activity of microorganisms.

Losses of organic matter and nitrogen during storage can be reduced by adding 2–3% by mass of simple powdered superphosphate.

Adding phosphate rock during manure storage is a method of effective use of fertilizer on neutral soils, where phosphate rock alone is ineffective. Under the action of a solution of carbon dioxide (carbonic acid) and organic acids formed during manure decomposition, tri-substituted phosphates pass into forms soluble in weak acids and available to plants:

In experiments of VNIIUA with different crops on sod-podzolic loamy soil, application of manure enriched during storage (composted) with phosphate rock (3% by mass) under potato and winter rye had a direct effect, and under spring wheat and perennial grasses had an aftereffect, ensuring an increase in the yields of these crops compared with their joint application in the same doses without preliminary mixing (composting).

Phosphate rock in an amount of 1–4% of the manure mass (10–40 kg/t), or in accordance with crop requirements, can be added to manure at any time from the moment it is obtained, but the earlier the better. For maximum effectiveness, it is most effective to add it in the stalls before removal, and with loose housing, immediately after applying the first layer of litter material. During removal, transportation, and stacking of manure, complete mixing and interaction of the rock with the manure is achieved; with loose housing, the animals themselves promote this process.

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

An accessible technique for increasing manure yield while simultaneously reducing losses of organic matter, slurry, and nitrogen even with compact storage is increasing the rates of litter materials, constructing manure storage facilities with slurry collectors, chopping straw, and using peat.

Manure Storage Facilities

Litter manure can be stored in manure storage facilities and on special areas in stacks.

Manure storage facilities can be:

• above-ground type, used when groundwater is close;
• pit type.

The above-ground type is preferable, since it is not flooded by precipitation and meltwater.

The following requirements apply to manure storage facilities:

• the manure storage facility must be located on elevated, non-flooded areas of relief, preferably surrounded by trees and agreed with sanitary-epidemiological stations.
• it must have a waterproof bottom and walls capable of withstanding the pressure of loading and unloading mechanisms, waterproof slurry collectors located taking into account the slopes of the bottom, convenient access, entrance, and exit with appropriate slopes, usually on the narrow sides of the storage facility.
• dimensions depend on the livestock population, volumes of manure during the stalling period, and stacking height. Per 1 head with compact storage 1.5 m high for 3 months, the required manure storage area is for cattle 2.5 m², including young stock 1.5 m², for horses 2.0 m², pigs 0.8 m², sheep and goats 0.3 m². When manure is removed twice during the winter period, the given areas are halved. The volume of the slurry collector should be at least 3–4 m³; their number is determined at the rate of 1.3 m³ per 100 t of manure.
• the manure storage facility is placed 50 m from the cattle yard; from other buildings and sources of drinking water, no less than 200 m.
• to collect slurry, a well is constructed at a distance of 1.5–2 m from the manure storage facility. The walls are laid with brick on cement. The well must be equipped with a manhole with two wooden covers.
• in the presence of infectious animal diseases or the content of quarantine weed seeds in manure, storage and use of manure is permitted according to instructions from veterinary and quarantine services.

Stacks are placed so that manure with different degrees of decomposition is not mixed. For this, they are placed from one end across the storage facility; then at one end there will be decomposed stacks (the first placements), and further toward the other end, increasingly less decomposed ones.

There are 8 variants of open manure storage facilities with a capacity of 3.20 and 4.25 thousand t of litter manure with 2 settling wells and 2 slurry collectors of 20 m³, designed for a six-month storage period. For areas of excessive moisture with precipitation of more than 600 mm, there are 4 variants of a covered two-section storage facility for 2.2 and 3.1 thousand t of litter manure. Two sections are provided for quarantine holding of manure for 5–6 months.

There are also several variants of on-farm concrete pads for compact storage of manure in stacks 5–6 m wide and 2.5–3.0 m high, divided into sections: for manure, peat, for mixing them, and for compact storage of the mixture (compost).

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

Manure is removed to the field in winter, since equipment is more available at that time. However, manure can be removed to the field at any time of year. Removal from manure storage facilities, cattle yards, and farms and stacking in the field in winter is done in 1 day, otherwise it will freeze, which leads to a decrease in fertilizing value. Sites in the field are chosen on elevated places, cleared of snow, covered with peat or chopped straw in a layer of 20–25 cm, and the manure is covered on top with peat or straw. Stacking is done in stacks 3–4 m wide and 1.5–2.5 m high, which are arranged in rows at distances (R, m):

where

10000

— area of 1 ha, m²;

D

— manure dose, t/ha;

W

— spreader working width;

G

— spreader load capacity, t.

Distance between stacks in a row R₂:

where

B

— mass of the stack, t;

W

— working width, m;

G

— spreader load capacity, t.

To destroy germinating weed seeds, the surface of the heaps is treated with herbicides.

Manure cannot be stored in small heaps, since nitrogen losses then reach 35–40%, it freezes, in spring it is washed by meltwater, the field is fertilized unevenly, and spring tillage is hampered.

With loose housing of livestock and a sufficient amount of litter, manure is removed from farms, yards, and areas with simultaneous application under crops. More frequent removal during storage under livestock is carried out only when litter materials are insufficient.

After spreading manure over the field, it is incorporated, since when stored in a spread state it dries out and nitrogen losses increase sharply.

Manure Application

Manure in Crop Rotation

Manure application is distributed among crop rotations and non-rotation areas in the order:

• vegetable;
• fodder (on-farm);
• field, taking into account specialization for the most valuable crops and distance from farms, pastures, and areas.

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

Vegetable crops are characterized by the greatest demand for soil fertility (5th class). They respond better to organic fertilizers compared with mineral fertilizers: trailing crops — cucumber, zucchini, pumpkin, melon, as well as onion, garlic, white cabbage, cauliflower, green crops, and radish.

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

In field rotations, maize for grain and sugar beet respond better to it. In field rotations, manure is also applied under potato and winter cereals. However, according to data from long-term (more than 50 years) field experiments of the Dolgoprudnaya Agrochemical Experimental Station, at equivalent nutrient doses, manure and mineral fertilizers are equivalent for potato, while for winter and spring cereals manure is inferior to mineral fertilizers.

In the Non-Chernozem zone, a good place for manure application in crop rotation is winter cover crops. In this case, the productivity of the crop rotation increases due to higher yields of winter crops, perennial grasses, and subsequent crops.

On acidic sod-podzolic soils, in the main application, manure application is combined with liming and application of mineral fertilizers. Manure is best applied under row crops if they are followed in the rotation by spring cereals with undersown grasses. On black fallows in the southern part of the Non-Chernozem zone, manure is applied during plowing of the fallow to a depth of 15–20 cm; on early fallows, before lifting.

On sod-podzolic soils, when applied under sugar and fodder beet, potato, maize, and other crops, manure is supplemented with nitrogen fertilizers; on light sandy and sandy loam soils, with nitrogen and potassium fertilizers; on irrigated ordinary chernozems and chestnut soils, with phosphorus fertilizers. The combination of manure and mineral fertilizers in crop rotation creates more favorable conditions for plant nutrition and improves soil properties. Organic and mineral fertilizers are equivalent when applied in doses equivalent in nutrient amount. On sandy soils, manure has some advantage, as it helps improve their properties. Therefore, when distributing manure among fields, it is advisable to apply manure to nearby fields and mineral fertilizers to distant ones.

In crop rotation, manure is best applied under a fallow-occupying crop, especially if it is a row crop. It is incorporated in autumn during plowing. If fallow-occupying crops are harvested early, manure is applied after their harvest before plowing, and the field is prepared for sowing of winter crops as a semi-fallow. Under spring crops, manure is applied in autumn under autumn plowing.

On light sandy and sandy loam soils, primarily in areas of sufficient moisture, spring application of manure gives a good effect. However, in steppe areas, spring application reduces effectiveness by 1.5–2 times compared with application under autumn plowing.

With an increase in the share of row crops in crop rotation, the payment of manure by additional yield increases. The place of manure application in crop rotation has little effect on productivity. However, it is somewhat higher when applied under highly productive row crops, for example, sugar beet, potato, and maize, since these crops most fully use manure nutrients in the first year.

The highest quality application and incorporation of manure in crop rotation is carried out in clean and occupied fallows, as well as after early-harvested predecessors.

Manure Doses

To determine manure doses for the planned yield in a crop rotation or for a crop for calculating nutrient balance, average data on the content in semi-rotted litter manure are used: nitrogen — 0.5%, P₂O₅ — 0.25%, and K₂O — 0.6%, that is, per 1 ton of manure — 5 kg of nitrogen, 2.5 kg of P₂O₅, and 6 kg of K₂O.

Manure is applied first of all under vegetable crops at a dose of 60 t/ha and potato — 40 t/ha with repeated application after 2 years. In field rotations, it is used once per rotation at rates of 30–40 t/ha.

Manure doses depend on quality, application methods, biological characteristics of crops and planned yields, and soil-climatic conditions. Thus, in northern, northwestern cold and humid areas, on poorly cultivated soils, higher doses are used than in the south, southeast, and on highly cultivated chernozems. At the same time, doses must be economically profitable and environmentally safe.

The minimum manure doses on poor (poorly cultivated) soils with pre-sowing (main) broadcast application with incorporation to the depth of soil tillage in zones of sufficient and excessive moisture are 20 t/ha; on fertile cultivated soils and in zones of insufficient moisture, 10 t/ha. With localized main application in furrows or rows, the minimum doses are reduced by 2 times; with localized application in holes, by 4 times. Localization and reduction of doses with any application method increase the payment per unit mass of manure by yield increases of the first fertilized crop in all soil-climatic zones.

On light poor soils, the increase is 1.5–2.0 times, and the payment per ton is 2–3 times higher than on loamy more fertile soils. Localized application of half doses provides the same increase in production under the first crop as a twice larger dose with broadcast application, while the payment of manure increases by 2 times.

With increasing doses, the return decreases. Thus, the greatest effect will be obtained from applying manure to 2 ha at 30 t/ha than to 1 ha at a dose of 60 t/ha.

With increasing manure doses, the increases of both the first and subsequent crops grow. Therefore, the effect of manure dose is assessed over all years of reliable impact on all crops of the rotation. In all soil-climatic zones, with increasing manure doses, the aftereffect is more significant than the direct effect.

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

With any supply of manure and other organic fertilizers within an agrocenosis, optimal doses are established after a preliminary assessment of the economic efficiency of possible options.

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

Cereal crops require lower manure doses compared with row crops such as potato, maize, sugar and fodder beet. Hemp, silage crops, cucumbers, and late cabbage varieties respond well to increased doses.

Doses of organic fertilizers are increased with growing planned yields. For the central regions of the Non-Chernozem zone, differentiated doses of organic fertilizers by yield levels are recommended for the most responsive crops.

The maximum doses in a specific case must be economically justified, that is, must ensure obtaining planned yields of good quality and expected profit, and environmentally safe, that is, the amount of nutrients must satisfy the needs of cultivated crops while maintaining optimal soil fertility properties; contamination of adjacent environments is unacceptable.

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

Various spreaders are used for manure application.

Effectiveness of Manure

The effectiveness of manure increases when it is applied together with mineral fertilizers.

In all agricultural zones of Russia, the greatest effectiveness is shown by semi-rotted manure obtained by compact storage. Bringing manure to humus is impractical, as it is associated with large losses of nitrogen, phosphorus, and organic substances. Fresh manure is also not used, as it contains weed seeds and disease causative agents, and a large amount of undecomposed nitrogen-free compounds that enhance immobilization of nitrogen, phosphorus, and other elements, acting as a competitor to plants. Therefore, crops sown after fresh manure may reduce yield in the first year due to nitrogen-phosphorus starvation at the beginning of the growing season. It is unacceptable to apply fresh manure under sugar beet, maize, and winter wheat if it is not after clean fallow.

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

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

In the Non-Chernozem region, semi-rotted manure is more often used; with autumn application, fresh manure is also effective.

In various soil-climatic zones, each ton of manure, when used correctly over all years of action in the rotation, provides additional production of 1 centner in terms of grain. Under irrigation on chernozems and chestnut soils, yield increases grow proportionally to manure doses, since plants with sufficient moisture supply use nutrients more fully.

Early varieties responsive to organic fertilizers and crops with a short growing season are fertilized in all zones with more decomposed manure, and late ones with less decomposed manure.

The effectiveness of manure under the first crop sharply decreases with increasing time between application and incorporation into the soil, since spread and unincorporated manure loses its ammonia content within 10–20 h.

The depth of manure incorporation into the soil with pre-sowing application is from 15 to 30 cm depending on soil-climatic conditions and degree of decomposition. Shallow incorporation into moist soil promotes manure decomposition. With a lack of moisture in arid conditions, shallow incorporation slows decomposition and further dries the soil. On soils heavy in granulometric composition, relatively shallow incorporation is necessary; on light soils, deeper incorporation.

On sandy soils, well permeable to water and air and warming quickly, manure decomposes intensively. At the same time, part of the nutrients may be leached. On such soils, manure is applied in small doses under several crops of the rotation. On clay and loamy soils, increased doses are applied, since on such soils it decomposes slowly and increases yield over a number of years.

Aftereffect of Manure

The effectiveness of manure in its action on the first and subsequent crops of a rotation decreases when moving from poor to fertile soils, and also with decreasing moisture supply.

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

On sod-podzolic and gray forest soils, the aftereffect in a rotation without row crops is 1.5 times, and with row crops 3 times, greater than the direct effect on the first (non-row) crop. With saturation of the rotation with row crops, the aftereffect increases. This pattern is also preserved with increasing manure doses.

On chernozems, the aftereffect is 4–5 times greater than the direct effect on the first non-row crop. When manure is applied under row crops, and also under favorable weather conditions, the direct effect increases sharply. When the rotation is saturated with cereal crops, the aftereffect decreases; when saturated with highly productive row crops, it increases. This is explained by the fact that row crops use the direct effect and aftereffect of manure more efficiently.

The advantage of manure on light soils is also preserved on limed sod-podzolic variants. On soils well supplied with organic matter, the positive effect of manure organic matter is not noted, but the advantage of mineral fertilizers does not exceed 5–10%.

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

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

The highest effect is noted under all crops and on all soils when organic fertilizers are combined with mineral fertilizers. Even at half doses, joint application always provides higher yield increases than separate application of doubled fertilizer doses. However, in practice, due to a shortage of organic fertilizers, manure has to be applied under one or two crops of the rotation, and under subsequent ones, only mineral fertilizers are added taking into account the aftereffect.

References

1. Mineev V. G., Sychev V. G., Gamzikov G. P., et al. (2017). Agrochemistry. Textbook. Edited by Mineev V. G. Moscow: Publishing House of VNIIA named after D. N. Pryanishnikov.
2. Yagodin B. A., Zhukov Yu. P., Kobzarenko V. I. (2002). Agrochemistry. Edited by B. A. Yagodin. Moscow: Kolos.
3. Evtefeev Yu. V., Kazantsev G. M. (2013). Fundamentals of Agronomy: Textbook. Moscow: FORUM.