PRODUCTIVITY AND ADAPTABILITY LEGUMS OF SOYBEAN IN AGRICLIMATIC CONDITIONS OF THE ARID ZONE OF THE VOLGA REGION IN SMALL CONTOUR AREAS OF DRIP IRRIGATION

The article considers the peculiarities of adaptation of leguminous crops on the example of soybeans to cultivation in the agroclimatic conditions of the arid zone of the Volga region when small-scale irrigated areas are put into circulation. The purpose of the research was to develop a resource-saving technology for cultivating leguminous crops during drip irrigation in small-scale areas, which includes the selection of a moisture-loving leguminous culture, differentiation of the irrigation regime by the moisture-consuming phases of its development with the assignment of watering standards and terms, the use of resource-saving methods of basic tillage, analysis of the effectiveness of the use of biologics, the use of irrigation water and the obtained productivity. When choosing a leguminous culture for the experience, priority is given to moisture-loving soybeans. The results of the analysis of the studies show that the use of soy drip irrigation in phenological phases requiring increased moisture supply, with a pre-plentiful moisture threshold of 70% HB at the beginning of the vegetation, 80% in the middle and 70% at the end of the period, ensures a stable level of its productivity. The developed technology of cultivating leguminous culture includes preparing the site for sowing - cultivation and laying of drip tape. Biologics with concentrated content of nitrobacteria are selected for treatment of seeds before sowing leguminous crops. It has been found that the use of Risoagrin 204 biologics to treat soybean seeds before sowing increases the formation of a large number of rhizobial nodules on the root system, which provide nutrition for the available forms of nitrogen throughout the development of the culture. The need for vegetation feeding in the phases: the end of stem branching and the beginning of ripening of beans has been confirmed. It has been proven that the introduction of microfertilities at the end of branching contributes to the growth of lateral branches and, as a result, the formation of more beans. The cultivation of legumes in small-scale areas during drip irrigation helps to ensure the stabilization of fertility and increase the return from the irrigated hectare, including by increasing the coefficient of land use. The complex of developed technological measures ensures the yield of leguminous crops up to 3.98 t/ha. As a result of the studies, the obtained indicators on morphology, biometrics, biological crop, protein content 36.14% and fat 19.87%, irrigation water consumption coefficient from 908 to 1119 m3/t, confirmed the prospects for soybean cultivation in small-contour areas during drip irrigation.