Tsvey Y. Scientific grounding of soil fertility restoration and increasing productivity of grain-beet rotation in the forest-steppe zone of Ukraine

The thesis presents theoretical and experimentally found new solution of scientific and practical problem of effective use of chernozems with the help of efficient rotations, soil tillage, ecological systems of their fertilizing with the use of biological nitrogen under conditions of the forest-steppe zone of Ukraine. Regularities of the changes of fertility of chernozem soils in different rotations depending on fertilization systems were found j principal parameters of soil fertility were worked out; interdependence of the rotation of phytosanitary state of crops, microbiological indexes of soil, balance of nutrient elements were grounded. The system of fertilization of farm crops in the rotation which guaranteed the increase of yielding capacity of farm crops and maintaining soil fertility was worked out. Models of different systems of grain-beet rotations were worked on the basis of agrochemical, biological indexes, systematic ecological and bioenergy analysis, which can guarantee odtaining 9,11-9,52 t/ha of fodder units in long-term rotations and 6,7-6,8 t/ha of fodder units in short-term rotations. On the basis of the results of these investigations, the recommendations for the use of rotation systems for the conditions of the forest-steppe zone of Ukraine were worked out.