The purpose of research is to predict the efficiency of ameliorants on Volga-Don interfluve irrigated lands. Mathematical statistics methods and experiment planning are used to build predicted dependencies between indicators of soil properties determining their fertility after applying ameliorants. The mathematical implementation of degradation processes reduction was applied in the framework of stochastic modeling tasks. The risk value of crop yield losses from degradation processes ξ, % can be considered as an indicator that combines the action of random environmental factors. Reducing the risk of yield losses is achieved by using an ameliorant in an optimal dose of N, kg/ha soil application. The risk magnitude of yield losses from degradation processes ξ and technical possibility of its prevention in different years are determined by comparing different deviation indicators. Taking into account the possibility of degradation processes a criteria η, is provided as a result of studies. It is noted that water stability and bulk density as well as nutrient elements after ameliorant application depend on humus content in direct proportion for chestnut soils of irrigated areas. There is a 3.2 % humus increase. In the studied areas the content of water-stable aggregates increased to 51.35 % (by the control – 43.21 %). Decreasing the bulk density to 1.10 t/m³ (control – 1.28 t/m³) contributed to arable horizon decompaction. Natural ameliorants based on local raw materials are advisable to use for degraded lands recovery in arid conditions, including the problems of moisture saving and moisture accumulation.
Keywords: soil degradation, ameliorant, water consumption deficit, glauconite sand, bentonite clay, humus, water stability, water-saving.
