Efficiency and balance of phosphorus for two crop rotations in making the annual and spare application of superphosphate and phosphorite meal in combination with manure and nitrogen-potassium fertilizers

In the condition of the systematic application of phosphate fertilizer plants unused phosphorus presents in the soil in a reversible condition in the four pools and respectively is available for plants in different amounts, providing a lasting effect as an aftereffect. However, unbalanced unilateral use of low pay and grain yield of phosphate fertilizers in three-field crop rotation determined the need for use of nitrogen- potash fertilizer to enhance phosphate plant nutrition. The purpose of the study is to research the effects of annual and reserve making of superphosphate and phosphorite meal made by N60K60 background and background with manure and N60K60 on crop yields and changes in the content of available phosphorus in the soil for two crop rotations. In many years of field experience of compared stationary forms of phosphate fertilizers in two crop rotations superphosphate with its reserve introduction in combination with manure and nitrogen-potassium fertilizers had the highest - 19.2 m s e/ha productivity of the crops, increased the content of available phosphorus in the topsoil of 11.8 mg/kg, low - 130 kg/ha increase in the costs of mobile phosphorus to 1 mg/100 g in topsoil.