Formation of water regime during irrigation by livestock waste

Abstract

The effect of long-term irrigation by livestock waste on the fertility of sod-podzolic soil has been studied in irrigation fields since 1999. At the same time, it has been found that as a result of fertilizer irrigation by livestock waste, the reliability of the specialized water rotation and amelioration system increases significantly during conducting agromeliorative practices that have a beneficial effect on the hydrological regime of irrigated lands. Depending on the moisture supply of the growing season during irrigation by livestock waste with an average nitrogen rate of 280 kg•ha -1 , in order to create an optimal water regime, it was necessary to carry out from three to six irrigations with one-time norms of 18-25 mm in different years. At the same time, irrigation norms ranged from 59-135 mm. Over the years of research, the water consumption of perennial grasses averaged 488.7 mm in control without irrigation, and 491-493.3 mm during watering by waste, depending on the conducted argomeliorative measures. The greatest total water consumption of perennial grasses was noted in the variant of irrigation by livestock waste against the background of drainless drainage combined with deep cultivation and the application of straw. Compared to the control without irrigation in irrigated variants, the total water consumption of perennial grasses was on average 85.2-90.3 mm or 21.1-22.4 % more. The water consumption of perennial grasses obtained by the calculation method for the sum of air humidity deficits using bioclimatic coefficients was 496.3 mm on average over the years of research and differed from the actual water consumption obtained in the experiment by no more than 5-10 %. On the basis of many years of research, it can be concluded that it is recommended to carry out deep cultivation (60 cm) and apply straw at a rate of 4.0 t•ha -1 to improve the water regime and agrophysical properties of soil during using livestock waste in irrigation fields. The effectiveness of agromeliorative practices has been observed for 5-6 years.