INFLUENCE OF CLIMATE, MINERAL FERTILIZERS AND PREVIOUS CROPS ON THE YIELD OF WINTER WHEAT IN THE EASTERN FORE-CAUCASUS

Abstract

The research was conducted in 2020–2023 on winter wheat crops after 3 previous crops on a natural and fertilized background by the Department of Agroecology and Agriculture of the Prikumsk Experimental Plant Breeding Station. The purpose of the research was to study the influence of previous crops, nutrient status and climate on the yield of winter wheat and the formation of structural elements in arid conditions of the Stavropol Territory. In comparison with 1990 – 2019, the hydrothermal coefficient in the studied years deteriorated in August by 0,35, October – by 0,27 and April – by 0,62 units, which had the most negative effect on soil cultivation, germination and the rate of biomass accumulation. The moisture deficit on the previous crops in the sowing period in the arable layer amounted to 31–51 %, and by spring in the meter layer 27–64 % of the annual average value. The share of precipitation in April – June in total water consumption was 67% for complete fallow, 77% for seeded fallow and 79 % for semifallow land, and 21–33 % of moisture was consumed from the soil. It was used most effectively in fallow, where the coefficient of water consumption decreased by 43–49 mm/t, in comparison to semifallow land. The highest density and the number of productive stems in all previous crops were observed in 2020 and 2022. The average yield for complete fallow in the control was 2,93 t/ha, with fertilizers – 3,51 t/ha, for a seeded fallow – 2,48 and 2.76 t/ha and a semifallow land – 1,06 and 1,67 t/ha. The use of fertilizers contributed to an increase in the number of stems by 14 % on complete fallow, on seeded fallow – the number of grains in the ear by 5,3 %, grain yield from the ear by 7,8 %. As for semifallow land, the parameters are as follows: growth in the number of stems by 13,0 %, the number of grains in the ear by 34,6 %, grain yield from the ear  by  37,5%.