Agrarian land use hydrothermal conditions in the Kulunda steppe affecting its sustainability

The aim of research is to study the temporal dynamics of hydrothermal conditions and their variation under the conditions of the Kulunda steppe (Altai Kulunda) as agroecological markers that affect the sustainability of agricultural land use. Objectives: to study the dynamics of hydrothermal conditions in the study area, to establish their effect on wheat yield in a time lag and the sustainability of agricultural land use. The object of the study is the territory of the Kulunda steppe (an area in the Altai Region, which is an agrarian territory, where the bulk of food grain is grown, despite the relatively low yield of agricultural crops (from 13 to 18 c/ha). The analysis of the hydrothermal conditions of the Kulunda steppe by subzones in the period from 1971 to 2003. The role of temperature, precipitation and their combined effect on wheat productivity was estimated, on the basis of which, through a system analysis, the dependence of the function (productivity) on the factors influencing it was built. The factors are arranged as their influence decreases: the consumption of moisture useful for plants from the layer up to 100 cm for the 5-8th months of the calendar year; hydrothermal coefficient (GTC) according to Selyaninov for June-July of the calendar year; the sum of temperatures above 10 °C for the 5-8th months of the calendar year; the sum of temperatures above 10 °C in the 0-20 cm soil layer for the 6th and 7th months of the calendar year; the amount of precipitation in the 7th month of the calendar year; a reserve of moisture useful for plants in a layer of up to 100 cm before planting seeds in the soil.