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Abstract. The aim of the research is to study the influence of the changed climatic conditions of the Belgorod region on the reserves of productive moisture in the soil and the yield of field crops using various methods of basic tillage. Research methods. Based on our own long-term research, the analysis of the effect of the increase in air temperature and the decrease in precipitation per year on soil moisture reserves and crop yields under various methods of basic tillage is made. Scientific novelty. An overview of the changes in the climatic conditions of growing field crops in the Belgorod region that have occurred in recent decades is given. Results. Agrometeorological observations have shown that in the period from 2006 to 2021, the air temperature in the surface layer increased, and the amount of precipitation decreased. Cases of extreme weather manifestations have become more frequent. Observations of the dynamics of moisture in a meter layer of soil in a stationary experiment determined that the climate changes that have occurred have affected its reserves. So at the time of sowing crops, there was a decrease in the amount of moisture in the soil by 15% of the average over the years, and when the crops were fully ripe, it decreased by 35-43%, without significant connection with the methods of basic tillage. The influence of extreme weather manifestations during the period of crop formation on crop yields is noted. According to the results of the research, it was concluded that there is a steady trend of decreasing moisture reserves in the meter layer of the soil, both at the time of sowing and during harvesting, regardless of the method of its main processing. There is no direct connection between the yield of field crops and the reserves of moisture available to plants at the time of their sowing and harvesting in the meter layer of soil and the method of its main processing.

The research is devoted to the study of the influence of precursors and mineral fertilizers, applied in various doses, on the agrophysical properties of the soil, the value of the grain yield of spring barley in the soil and climatic conditions of the Central Black Earth region. The field experiment was based on the long-term hospital of Belgorod State Agrarian University named after V. Ya. Gorin. As an object, the variety of spring barley Knyazhich, recommended for the region, was chosen. The soil of the experimental plot is typical chernozem, medium loamy granulometric composition on loess-like loam. The experiment scheme (4×4) provided for the study of four gradations of factor A (predecessors: corn for grain - control, sunflower, sugar beet, soybeans) and factor B (doses of mineral fertilizers: N10P10K10 - control, N30P30K30, N50P50K50, N70P70K70). Growth and development of spring barley plants in 2018-2020 took place in meteorological conditions characterized as arid with a predominance of elevated temperatures and insufficient precipitation during the critical phases of plant vegetation. The results of field experiments established that the water and agrophysical properties (density and structural-aggregate composition) of the soil under the influence of previous crops approached the optimal values and changed insignificantly. Increased doses of mineral fertilizers had a positive effect on the value of the yield of barley grain according to the studied predecessors. The highest grain yield over the years of research was obtained at high N50P50K50 and intensive N70P70K70 backgrounds for the predecessors of soybeans and sugar beets and amounted to 5.48 and 5.03 t/ha and 5.33 and 5.32 t/ha, respectively. This was higher than the control of corn for grain 0.82 and 0.37 t/ha and 0.62 and 0.61 t/ha, while for sunflower it decreased to 4.06 and 4.71 t/ha and was at the level with the control.