Water-physical properties of chestnut soils depending on different tillage practices and irrigation regimes

The aim of the research was to study water-physical properties of chestnut soils under different tillage practices when cultivating corn (Povolzhsky 89 MV hybrid) under irrigated conditions in the Lower Volga region. Therefore, the following characteristics of the soil were studied - soil density, soil moisture, field capacity, maximal hygroscopic moisture, wilting point and porosity. The results revealed that after chisel loosening, a qualitative improvement of soil water-physical properties was observed in comparison with the control variant - moldboard plowing. To describe the dynamics of changes in soil density by layers and tillage variants, a regression of the 2nd order was proposed, and coefficients of the equation were calculated. In order to maintain the specified irrigation regime during the observation periods, 7 to 9 vegetative irrigations with application rate from 2250 to 2750 m3·ha-1 were carried out in the variants with moldboard plowing, 7 to 8 irrigations with application rate from 2200 to 2600 m3·ha-1 in the variants with chisel loosening, and 6 to 7 irrigations with application rates from 2100 to 2500 m3·ha-1 in the variants with chisel moldboard plowing. The yield of corn in the variant with chisel moldboard plowing averaged 8.75 t·ha-1 during the research period, which is 18 % higher than in the control variant. Moreover, the cost of irrigation water for producing one ton of grain decreased by almost 20 %, and the coefficient of water consumption decreased by 17 %.