THE CONTRIBUTION OF SOIL NITROGEN AND FERTILIZERS TO THE FORMATION OF CROPS OF AGRICULTURAL CROPS IN SOD-PODZOLIC SOILS

Abstract

Nitrogen of soil stocks prevails in nitrogen nutrition of grain crops. The yield of winter rye grain by 60-85 %, barley and spring wheat - by 66-75, legume-cereal mixture - by 88-92 % due to the nitrogen of the soil. With increasing rates of nitrogen fertilizers and their fractional introduction of their share in the formation of the crop increases. Of the forms of nitrogen fertilizers, the lowest specific gravity of nitrogen of fertilizers in its total removal was on automorphic soil in the variant with urea, the forms of introduced nitrogen did not differ on the gley soil. In the grain of winter rye on sod-podzolic light loamy soil, 75-78 % of the total nitrogen absorbed by plants of fertilizer was concentrated, on sandy soil - 68-70 %. Barley grain contains 80-84 % nitrogen of fertilizers from its total removal with the main and secondary products. With increasing rates of fertilizers and their fractional application, an increase in the accumulation of nitrogen in the grain is observed. The forms of nitrogen do not have a noticeable effect on the structure of its consumption by the base and by-products. More significantly affects the degree of hydromorphic soil. The utilization of nitrogen fertilizers on sod-podzolic soils varies from 20 to 62 % and depends on the level of soil fertility, cultivated crops, rates, timing of application and forms of nitrogen fertilizers. Fractional use of nitrogen contributes to an increase in its utilization rate, while a decrease in the rate of nitrogen fertilizers is observed to decrease.