Management of the production function of soils on erosion-prone lands: technology and examples

The soil resource in modern conditions of total exploitation requires the development of adequate management models. The mathematical apparatus of such management has been developed, which can be used to regulate the rate of erosion «wear and tear» of soil as a production resource, with the idea of successful exploitation of this resource in the medium term. Such a procedure can be part of a more general task of managing soil functions under conditions of intensive soil use in areas of active agricultural activity. As a quantitative definition of the production function, it is proposed to use the integral of the dependence between the values of the modified Pierce productivity index in each soil layer and the depth of this layer. The modified productivity index, which was developed for a meter-long layer of ordinary chernozems of the Right-Bank Steppe of Ukraine, includes five main productivity parameters – humus content, mobile phosphorus, exchangeable potassium, soil density, and soil solution pH, which were normalized from 1 to 0. Procedures for normalizing each of the indicators are presented, showing their impact on soil productivity. The control procedure is a comparison of the actual change in the value of the production function that occurred over time with the permissible (or threshold) value. It is proposed to use the value of the production function for slightly eroded soil as an acceptable value. If, during operation, after a predetermined time (30 or 50 years), the value of the soil production function is greater than the permissible value, then erosion degradation of the production function does not occur. If during this fixed time of soil exploitation, as a result of erosion, its production function becomes less than the permissible value, and then it is necessary to adjust land use procedures by implementing various soil protection measures. Practical application of the methodology on a specific example of a land plot with ordinary non-eroded chernozems located in Voznesensky district of Mykolaiv region. The implementation of the developed mathematical procedure for managing the production function of chernozem soils has shown that replacing the current technology of growing crops with the «no-till» technology or reducing the share of row crops and black fallow in the structure of sown areas helps to reduce the accelerated erosion degradation of ordinary chernozem to acceptable values.