The problem of substantiating the erosion-induced permissible soil loss and an approach to its solution

It is shown that to develop a strategy for the rational use of soil resources, a methodology is needed that should include methods for solving the following tasks: an objective assessment of soil resources; the evaluation of their dynamics over the past time; long-term forecasting of the dynamics of these resources; the search for trade-offs between the need to reduce soil degradation (erosion) and the available economic opportunities. On the example of eroded chernozems of arable lands in the Kursk region, the solutions to these problems are considered. The amount of soil resources was estimated by the area of ​​arable land and the thickness of the humus horizon, and their quality (fertility, productivity) - humus stocks in the 0-50 cm layer. The dynamics of soil resources was estimated from the change in these parameters. Data on the reduction of chernozem resources are given approximately 200-250 years after plowing of virgin land. It is shown that restoration of humus layer capacity of eroded chernozems will take millennia, and restoration of humus resources - a century. In a large area of ​​arable land, it is almost impossible to stop erosion in a relatively short time. The strategy for reducing erosion includes stages for which an approach is proposed for assessing the permissible erosion loss of soil (DEPP). This approach is a search for a compromise between the rate of soil formation, the change in the thickness of the humus horizon, the productivity (quality, fertility) of the soil, the random nature of the erosion processes and, on the other hand, erosion measures in accordance with the available economic opportunities. The DEPP values ​​should decrease from stage to stage, approaching the rate of soil formation. The values ​​of DEPP for the first stage (without economic evaluation) are developed.