Erosion-permissible irrigation norms on southern chernozems during sprinkling

Abstract

The currently existing traditional approach to calculating the water consumption of agricultural crops is based on a shortage of soil moisture, in which the irrigation rate is determined taking into account the degree of desiccation of the soil at the time of irrigation, its water-physical properties, the depth of soaking and irrigation techniques. The subsequent determination of the elements of sprinkling irrigation technique is based on the obtained irrigation rate without taking into account the strength properties of the soil, its resistance to the effects of artificial rain energy, as well as the possibility of erosion processes. However, the practice of sprinkling irrigation in various climatic zones of the country shows that one of the main problems of sprinkling is the formation of surface, uncontrolled water runoff during irrigation, which leads to irrigation erosion of the soil, loss of water to runoff and deep focal infiltration, which, in turn, worsens the reclamation condition of the irrigated area, and ultimately – to a significant decrease in the effectiveness of sprinkling and its environmental safety. The methodology for assessing the use of sprinkler devices depending on soil conditions, based on comparing the average intensity (layer) of rain with the rate of absorption (layer) of absorbed water during the irrigation period in one position does not exclude these negative consequences during sprinkling. It is established that when justifying erosion-permissible irrigation norms, the indicator of free (nonpressure) water permeability, which depends on the size of raindrops and its intensity, should be used as a criterion for assessing water absorption into the soil.