INFLUENCE OF MINERAL FERTILIZER RATES ON THE DYNAMICS OF NITROGEN IN PLANTS AND THE YIELD OF WINTER WHEAT CULTIVATED IN THREE SOIL-CLIMATIC ZONES OF THE CENTRAL CIS-CAUCASUS

Abstract

Increasing the productivity of agricultural crops by optimizing mineral nutrition is a priority area of ​​scientific and technical development of our country, approved by the decree of President Putin V.V. dated June 18, 2024 No. 529. In this regard, in 2023-2024, in three climatic zones of the Central Ciscaucasia, single-factor experiments were conducted in production conditions in three replicates, where factor A is the fertilizer rate (recommended and calculated for the zones). The scientific novelty of the research was that for the first time in three soil-climatic zones (moderate, unstable moisture, arid) of the Central Ciscaucasia, the effect of mineral fertilizer rates on the dynamics of nitrogen in plants and the yield of winter wheat was studied. In the moderate moisture zone, in the tillering phase, winter wheat plants had a low nitrogen supply level (3.25%) in the control, and an optimal one (4.15, 4.46, 4.64%) in the variants with the calculated rates of mineral fertilizers applied. In the unstable moisture and drought zones, in the control (4.13%; 4.28%), it was optimal, and in the fertilized variants, it was high (4.88, 4.68, 5.07%; 4.71, 4.70, 4.91%). In the heading phase, in all three farms, the concentration of the element was low (1.26, 1.60, 1.77, 1.90; 1.98, 2.11, 2.28, 2.77%; 1.68, 2.19, 1.89, 2.23%). In 2023, the rates of mineral fertilizers compared to the control significantly increased the yield of winter wheat by 2.68, 3.27, 4.36 t/ha (moderate moisture), by 0.81, 2.14, 3.26 t/ha (unstable moisture), by 0.88, 0.61, 1.48 t/ha (arid zone). In 2024, in the zones of moderate and unstable moisture, the same dynamics in increasing crop productivity were observed (by 1.10, 2.09, 2.44 t/ha and by 1.06, 1.80, 2.92 t/ha). In the arid zone, only the calculated rates of mineral fertilizers in relation to the control reliably increased the yield of winter wheat by 0.46, 0.98 t/ha.