Humus condition under different systems of basic cultivation of dark gray forest soil

Studies, were conducted in a stationary experiment between 1988 and 2018 on dark gray forest heavy loam soil in Scientific Research Institute of Agriculture for Northern Trans-Ural Region - Branch of Federal State Institutions Federal Research Centre Tyumen Scientific Centre of Siberian Branch of the Russian Academy of Sciences. The aim of the study is to determine the effect of long-term (30 years) impact of different systems of basic cultivation of dark gray forest soils in the cultivation of grain crops on the humus content. Observations were made according to generally accepted methods during 6 rotations of grain and fallow crop rotation: bare fallow, winter rye, spring wheat, spring vetch, spring barley, unfolded in time and space. The impact of the combined system of tillage with alternation of plowing and no-tillage at 20-22 cm during 6 rotations of a 5-pole grain and steam crop rotation (30 years), increased the humus content in the 0-40 cm layer of dark gray forest soil compared with the initial content by 0.42%. The systems of main tillage - differentiated, without sowing, and mouldboard provided in general a relatively favorable dynamics of the humus state of the soil. The content of humus in the 0-40 cm layer of soil by differentiated and unswept systems during the study period remained close to the initial condition. По отвальной системе содержание гумуса снижалось на 0,22% или в среднем 0,37т/га в год. The greatest loss of humus in the 0-40 cm layer of soil by 0.80% in relation to the initial was the impact of surface treatment with annual discing BDT-2,5 (heavy disc harrows) on 10-12 cm or an average annual loss of 1.33 t / ha