Cropped rotations agroecological assessment as the basis for organizing a sustainable agricultural landscape

The purpose of the study is an agroecological assessment of existing crop rotations in the arid steppe of the Altai Region in order to optimize them and increase the sustainability of agricultural landscapes. Tasks: to assess the productivity of agrolandscapes in municipal areas of the arid steppe in the period from 2002 to 2018; calculate the balance between the processes of mineralization and humification of organic matter in the existing system of crop rotations for the indicated lag. The objects of study are agrolandscapes of the arid steppe of the Altai Region and crop rotations cultivated in them. The soil cover is dominated by southern chernozems and chestnut soils. The quantitative and qualitative characteristics of the territory were obtained from the publicly available materials of the Office of Rosreestr for the Altai Region, and the materials obtained as a result of the study were also used. The generally accepted methods used in the study of complex multifunctional systems were used: a systematic approach (analysis) used for a comprehensive study of probabilistic systems, which include agrolandscapes of the arid steppe, as well as historical, retrospective, abstract-logical, ecological-landscape methods, methods of information analysis and synthesis. For 9 municipal districts located on the territory of the arid steppe, and for the subzone as a whole, the annual amount of biomass formed in agrocenoses under grain crops was calculated, and also the statistical characteristics of the variability of grain yield for the period from 2002 to 2018 was determined. The range of variation in the primary productivity of agrophytocenoses by subzone is 4.1 t/ha, and the average grain yield is 1.0 t/ha. The probability of years with different levels of grain crop yields by districts for the studied lag was established. The balance (losses and gains) of organic matter for a crop rotation system cultivated in the arid steppe of the Altai Region was assessed. Of the 18 crop rotations recommended for the arid steppe, 12 have a negative humus balance. Annual losses of humus in these crop rotations range from 0.063 to 0.987 t/ha. All crop rotations with a negative balance are divided into five groups, which differ in the degree of humus loss due to mineralization.