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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.


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
On pig farms
At the stables

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.


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.


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.