Humus State of Soils in the System of Landscape Agriculture in the Conditions of the Middle-Russian Upland, Russia

Soil erosion is a catastrophic problem for the world's environment, including agro-ecosystems in erosion-dangerous regions of Russia. Studies were performed in the most eroded district (Krasnogvardeiskiy) of the most eroded area (Belgorod) in the Central Chernozem zone of Russia. The aim was to study the effect of soil-protecting technologies on the dynamics of organic matter in soil monitoring survey system in real conditions of agricultural production during 27-29 years. As a result, positive dynamics of organic matter content in soils of two model facilities and the district as a whole was found. During the studied period, the content of organic matter in the soils of the "Repny Log" facility increased by 0.30% in the 0-20 cm layer, and by 0.75% in the 20-40 cm layer, in the soils of the "Krasnogvardeiskiy Range" facility - by 0.79% (20 -40 cm) and by 0.50% (20-40 cm), in whole for the Krasnogvardeiskiy district - by 0.4%. However, the rate and direction of the soil-forming process in various periods of time have been non-uniform and depended on the degree of landscape agricultural systems development, as well as on the relief conditions and the state of soil cover. While in the 0-20 cm soil layer of the "Repny Log" facility there was first a 10-fold reduction in organic matter loss followed by its accumulation at the rate of 0.05% per year, the 20-40 cm layer is initially characterized by a statistically significant increase in this indicator. Study of humus soil status of the "Krasnogvardeiskiy Range" facility established a statistically significant increase in organic matter content in topsoil and subsoil by 29% and 20%, respectively, for the whole water catchment. Thus, landscape agricultural systems are able not only to reduce the rate of soil erosion, but also to prevent it and to enhance soil fertility. This provides a basis for decision-making about their large-scale development in erosion-dangerous regions with intensive agricultural production.