Home – Home – Jornals – Geography and Natural Resources 2023 number 3

We examine the present status of the main type of agricultural land, namely arable land. An assessment is made of the growing negative trends in the ratio of the main biological groups of agricultural crops and clean fallow when using arable land. With such a structure of the use of arable land and crops in soils, a negative balance of organic matter - humus, the main indicator of the favorable agroecological state of soils, has developed. In large agricultural enterprises, the share of clean fallow reaches 24,8 %, and in peasant farms the share reaches 30 %, which together with grain crops makes up 71-80 % and characterizes the farming system as an extensive type of grain-fallow system. The proportion of perennial grasses and siderates is extremely low and does not allow maintaining the balance of humus at the level of deficit-free. It is shown that in most agricultural areas there is a grain-fallow system of using arable land, the structure of crops is dominated by spring wheat, which is practices in clean fallow. This is due to the fact that in conditions of high cost and shortage of mineral and organic fertilizers, it is impossible to increase the yield of wheat by non-fallow precursors, because the level of natural fertility of the soils in Irkutsk oblast without fallowing and fertilizers does not exceed 13-15 centers/ha. To eliminate the imbalance of organic matter content in the soils of the region, it is proposed to replace some of the clean fallow lands with sideral ones and increase the proportion of the areas of perennial grasses, while the optimal share of grain crops should make up 45-50 % in the structure of arable land.