Soil moisture loss reduction owing to evaporation

Abstract

Soil-climatic conditions of arid regions of Russia have a great potential for obtaining high yields of various crops, but the constant lack of soil moisture hampers the increase in production volumes. However, the deficiency of soil moisture is due not only to a lack of atmospheric precipitation, but also to inefficient saving. Moisture losses because of unproductive evaporation reach 40-70 percent of atmospheric precipitation. One of the effective ways to accumulate and conserve soil moisture is the autumn shallow mulching tillage, which creates a loosened top layer of soil with a mulched surface. The top layer of soil during loosening and mulching promotes the accumulation and conservation of moisture not only in the upper, but also in the deeper soil horizons. A new combined tillage tool was developed and manufactured to implement such tillage. The tool is equipped with 2 batteries of knife disks placed in two rows one behind the other, with flat hoes arranged in two rows in staggered order, and a roller with pins mounted on its working surface. When soil cultivation by the proposed tool, a qualitatively loosened layer with a mulch surface is created. Enhanced water permeability and moisture capacity increase the penetration of atmospheric precipitation into the soil and reduce the loss of moisture owing to evaporation. The research carried out to determine the loss of moisture due to evaporation, depending on the type and quality of soil cultivation, have confirmed the advantage of the proposed type of tillage. The reserves of productive moisture in a 1 m soil layer increase by 31.8; 25.8 and 16.8 mm in comparison with fields without tillage, shallow tillage by disc mulcher DM-5.2 and by cultivator KPIR-3.6 respectively. The productivity of barley variety Volgar' at the area cultivated by experimental tools was 2.24 t per hectar, by KPIR-3.6 – 2.12 t, DM-5.2 – 2.02 t, without tillage – 1.46 t per hectar.