COEFFICIENTS OF UTILIZATION OF NITROGEN, PHOSPHORUS AND POTASSIUM FROM THE SOIL AND FERTILIZERS BY WINTER WHEAT AND BARLEY IN THE CONDITIONS OF IRRIGATION

In the irrigated soils of winter wheat and barley the problem of the degree of absorption of nutrient elements from the soil and fertilizers is observed. In the conditions of field experiments (2020-2022) the coefficient of the utilization of nitrogen from the soil (CUS) by wheat and barley varied from 44,4 to 54,4%, P2O5 – 26,3-31,5 and K2O - 4,9-6,1%. Coefficients of the utilization from mineral fertilizers (CUF) by the investigated plants were: nitrogen – 49,6-82,8; P2O5 – 29,4-38,4 and K2O - 56,4-74,6%, and from semi-rotten manure and biohumus – 54,3- 70,4; 25,8-43,0 and 33,5-141,1%, respectively. The balance coefficients of the utilization of nutrient elements by the investigated crops in fertilized variants are higher than 100%, which explains the deficiency of the applied doses of organic-mineral fertilizers (N120P80K90), as a result of which in these farms the deficit of nitrogen, phosphorus and potassium deepens and is accompanied by gradual dehumufication of the soil.