Balance of winter precipitation in soil-climatic zones of the Omsk Region

Abstract

In four soil-climatic zones of the Omsk Region, the patterns of autumn landscape soil moistening and winter precipitation assimilation were revealed based on water regime analysis on 12-year permanent water balance plots. The features of influence of agrophysical upper-layer parameters (compaction, moisture content, permafrost) on water permeability and snow assimilation were determined. It was found that the decrease of meltwater soil assimilation was greater the higher the autumn moisture content and denser the upper-layer structure. Other factors affecting the efficiency of meltwater utilization were also revealed. For example, vegetation in fields helps retain snow, improve its distribution which in turn benefits soil moistening and crop yields. It is emphasized that the choice of agronomic practices should be based on regional climate and soil characteristics as some methods may be more or less efficient depending on the local conditions. For example, in regions with frequent and heavy precipitation such as rains, snow retention may not be necessary as the soil already gets sufficient amount of moisture. Instead, other methods such as stubble retention or plantings that help retain moisture in the soil may be used. In arid steppe soil-climate agro-landscapes, using a complex of techniques that accumulate moisture in grain-tilled crop rotation (strip fields in fallow, top-cut stubble, and combined snow retention by snow compactor and ridger) increases the snow accumulation factor to 0.82-0.90 (by 25-34 mm) and the yield of spring wheat grain by 0.22-0.33 t ha (16-24%).