Field crop rotations formation features in the Western Siberia forest steppe

The purpose of the study is a technological assessment of the impact of crop rotation for the formation of field crop rotations in the forest-steppe conditions of Western Siberia. The analysis of the soil-climatic zonality of the territory of the forest-steppe of Western Siberia was carried out, the degree of population, the contour of the fields, the biological economic characteristics of crops, including the leading one - spring wheat, were determined. An adaptive-landscape approach was applied to the zonal features of crop alternation, which makes it possible to determine a reasonable ecological niche for each, select crops in accordance with biological requirements, productivity, profitability of production, and minimize repeated and permanent crops as much as possible. Monitoring of the economic activity of the last 35 years has shown a tendency for the stratification of commodity producers by resource capabilities, technical equipment, and, above all, the level of agricultural intensification. In this regard, recommendations for optimizing field crop rotations are guided by the expansion of up to 8–10 crops and adaptive varieties, taking into account their profitability and "soil improvement", limitation of repeated crops, exclusion of permanent cultivation of crops. Under conditions of limited intensive farming, about 5–10 % of the arable land area belongs to crop rotations with winter crops, row crops, legumes, melilot, rapeseed, millet, clover, annual multicomponent grasses, the efficiency of which in terms of the yield of fodder units is often superior to grain-fallow crop rotations with short rotation. It is noted that in recent years, special attention has appeared to fruit-changing crop rotations, which allow, with an increase in the culture of agriculture and the use of intensification means, to somewhat reduce the fallow field and optimize the structure of arable land use, increase the biodiversity of a set of crops and adaptive varieties. The transition to fruit change for producers of a more humid forest-steppe zone is possible only with the use of fertilizers and the improvement of agrophytocenoses. The expansion of crop rotation and a reduction in re-sowing of spring wheat are also due to positive changes in hydrothermal conditions in the arid soil-climatic zones of Western Siberia.