The role of snow retention in regulating water balance and productivity of spring wheat in biologized crop rotations in the rainfed zone of Akmola region

Abstract

Background and aim. Akmola region is an arid region, where the annual precipitation averages 320-360 mm, a significant part of which falls as snow. At the same time, the height of the snow cover in the region accumulates due to the stubble of grain crops of 15-25 cm, the remaining precipitation in the form of snow is carried away to forest belts and does not participate in the formation of the grain crop yield. The purpose of the research was to study the effect of snow retention on the soil water regime and the yield of spring wheat in a biologized short-rotation crop rotation with green manure fallow.

Materials and methods. For three years, observations were made of the state of snow accumulation, background moisture supply and spring wheat yield after green manure fallow with a pea-oat mixture. At the same time, the qualitative indicators of the snow cover (height, density and water reserve) were determined. After the snow melted, before sowing wheat, and also before harvesting, the reserves of productive moisture in the meter-thick soil layer were determined. At the end of the growing season, the wheat yield was recorded.

Results. In the areas where wheat was sown as the first crop after green manure fallow, the best indicators of the water-physical properties of the soil and crop productivity were noted in the variant with snow retention. Snow depth - 37.3 cm, water reserves in snow - 115.7 mm, reserves of productive moisture in the soil before sowing - 122.4 mm. In the areas where wheat was sown in the crop rotation as the fourth crop after green manure fallow, the best indicators were also in the variant with the use of snow accumulation techniques. Snow depth - 52.8 cm, water reserves in snow - 132.0 cm, reserves of productive moisture in the soil - 124.2 mm. At the same time, the lowest soil density indicator was recorded in this variant - 1.21 g/cm³ and 1.18 g/cm³ on the first and second backgrounds, respectively. The yield of wheat grain in the variants with the use of snow retention on both backgrounds was the highest - 18.4 c/ha and 14.5 c/ha, respectively.

Conclusion. Despite the dry climatic conditions during the years of research, the use of snow retention had a positive effect on the accumulation of moisture in the soil and on the formation of wheat yield.