COEFFICIENT OF THE USE OF 15N LABELED NITROGEN BY GRAIN CROPS UNDER THE CONDITIONS OF DARK CHESTNUT SOILS OF THE DRY STEPPE ZONE OF KAZAKHSTAN

Abstract

The article presents the results of research conducted for the first time with the stable isotope of nitrogen 15N in the conditions of dark chestnut soils of the dry steppe zone of Kazakhstan. The main information about the nature of biological and chemical processes of nitrogen transformation in the soil and quantitative assessment of plant assimilation of nitrogen fertilizers introduced for spring wheat and triticale are presented. According to the results of the research, it was established that spring triticale uses nitrogen fertilizers more intensively than spring wheat. For both crops, the application of N30 before sowing and N30 in tillering showed a higher efficiency compared to other options, depending on the amount of fertilizer and the timing of application on the background of P60 and P0. According to the results of the conducted experiments, it was established that the main part of the applied nitrogen fertilizers (60-62%) accumulates in the grain. Nitrogen fixation in the soil accounted for 20 to 39% of fertilizers applied for spring wheat and 30 to 45% for spring triticale.