Продуктивность кормовых культур и основные принципы применения удобрений на мелиорируемых землях Калмыкии

Abstract

The Republic of Kalmykia, due to its geographic location and sharp continental climate, is characterized by an acute shortage of productive moisture and basic nutrients in the zonal soil subtypes. Intensification of field fodder production and creation of a stable fodder base in the republic requires a more efficient use of irrigated lands. One of the most important directions for increasing productivity of irrigated lands is growing crops in the system of obtaining two or three yields of annual forage crops per year with the development of a rational fertilizer application system. Cultivation of such crops with alfalfa, forming high yields of aboveground biomass in a short period (50-65 days), make it possible to obtain three crops under irrigation during the warm season. The research has shown that corn, sorghum, Sudan grass as main crops, and winter rye as inter crop had the greatest productivity under optimization of water and fertilizer soil regimes in the Caspian lowland conditions. Ecological agriculture demands a rational approach to the selection of highly productive annual forage crops, considering climatic characteristics of the territory, biological requirements of crops and soil fertility level. It was found that high doses of nitrogen fertilizers were inappropriate for annual forage crops grown after alfalfa. The results have shown that moderate doses of nitrogen and phosphorus were quite effective in irrigation. Moreover, it is necessary to maintain the optimal water regime of soil at the level of 75-80% FC using modern sprinklers. The purpose of the study in 2018-2020 was to develop a basic model for obtaining three harvests per year with optimization of main technological processes (irrigation, fertilization) on light chestnut subtype of soils in the Caspian lowland.