Tamara Ivanovna Khusnetdinova

The article summarizes and presents the results of long-term studies on the effect of mineral, organic fertilizers and liming on crop productivity depending on the degree of cultivation of sod-podzolic soil. It is shown that fertilizers act as a powerful factor capable of increasing the yield of agricultural crops and improving their quality, that the yield of field crops is directly dependent on the degree of cultivation and fertility of the soil. It is shown that in sod-podzolic soil of varying degrees of cultivation, complete or partial replacement of urea with MFU in the composition of triple (NPK) mineral fertilizer does not solve the problem of increasing the efficiency of nitrogen fertilizers. When studying the productivity of grain crops (winter wheat, winter rye, spring wheat, oats, barley), it was found that regardless of the form of nitrogen fertilizers, the optimal dose of NPK for all the above crops did not exceed 100–150 kgha-1 of the active substance of each element. This dose made it possible to realize the potential of the studied varieties of grain crops by 60–80%. The efficiency of nitrogen doses over 100 kgha-1, both when using urea and its combinations with MFU, leads to deterioration of the enzymatic activity of soils. The level of cultivation of sod-podzolic soil remains decisive in the formation of agricultural crop yields and with intensive use of fertilizers.