ECOLOGICAL EVALUATION OF LEACHED CHERNOZEM UNDER INTENSIVE CROP FARMING IN THE SOUTHERN FOREST-STEPPE OF THE OMSK REGION
The data of biotest of leached chernozem phytotoxicity in the long-term stationary experiments at 42 years long and 28 years long use of conservation tillage on the basis of 5-course cereal-fallow and 4-course crop rotations under intensive cropping is presented. Moderate rates of fertilizers and pesticides increased the root length of the test-crop. In the middle of summer high chemical load temporarily reduced the length of radish roots in the tillage variants of different intensity and with chemical application. In the barley field as the last crop in crop rotation long-term use of fertilizers and the accumulation of plant residues produced positive effect on the growth of radish roots in the soil extract this variant. In the soil extract from the topsoil from the wheat field (the last field of the crop rotation) slower growth of the test-crop was observed at the end of the growing season. Weak phytotoxic effect after chemical application (fertilizers, herbicides, fungicides and retardants) was detected. The root length of radish as a test-crop in determining soil phytotoxicity was also affected by solar activity. Solar activity significantly affects radish sprouts on the day of seeds soaking before thermostating. In the variants with soil extracts this interaction was revealed in lesser extent.