Restoration of moisture reserves in the soil in the grain-fallow crop rotation before sowing spring and winter wheat in the Saratov Trans-Volga region

Abstract

As a result of many years of field experiments, it has been established that in the Saratov Trans-Volga region, after autumn-winter precipitation in a meter-long layer of soil, moisture reserves corresponding to the lowest moisture capacity are not restored. In a clean fallow after sunflower, soil moisture reached maximum values of 81–86% HB in three years out of six, 70–76% HB in one year, and less than 70% of minimum moisture-holding capacity in two years. On average, over six years, soil moisture changed from 72% at minimum tillage to 76% of minimum moisture-holding capacity at deep non-moldboard. During the period of sowing winter wheat in clean fallows, on average for six years, soil moisture remained at the level of 61.9–65.8% of minimum moisture-holding capacity. Such insignificant reserves of moisture in the soil without September precipitation do not provide friendly seedlings and normal development of winter wheat. Before sowing spring wheat after the predecessor - chickpea, the highest humidity reached only 75–82 % of minimum moisture-holding capacity for three years. The minimum values of soil moisture at the level of 57–64 % of minimum moisture-holding capacity were for two years. Experimental data obtained over six years (2017–2022) show that a 10–12 cm main tillage reduces the yield of winter wheat by 0.37 t/ha, or by 14.6%, of spring wheat by 0, 29 t/ha, or by 24.8%.