Efficiency and Soil-Protective Role of a Direct Seeding System on Russian Chernozems
摘要
The data on typical and ordinary chernozems are reported for the field experiments and commercial farms practicing direct seeding and recommended tillage technologies in the Stavropol region. In the case of recommended tillage technologies, the characteristics of chernozems are declined; direct seeding helps to restore them. The efficiency of direct seeding appears as an increase in the organic matter content and improvement of hydrophysical, agrochemical, and biological properties of chernozems. In the first eight years of no-till farming, the humus content in the topsoil (0–30 cm) layer of ordinary chernozems increases by 0.22–0.29% owing to the activation of the fauna and microbiota in the decomposition of postharvest residues on the soil surface, which perform the main ecological function of soil protection from water and wind erosion. This is most typical of corn and sunflower residues. The available water content during the growing season in the layer of 0–150 cm of ordinary chernozem with no-till farming is, on the average, by 132 mm higher according to the data on six years of studies performed for soybean/pea, winter wheat, sunflower, and corn crops. Mineral fertilizers increase crop yields in different subtypes of chernozems.