Annotation

The paper affords the impact of integrated method of soil reclamation comprising green manure and application of different doses of phosphogipsum and mineral fertilizers (MF) calculated for planned yield on physical, chemical, agrochemical properties of darkchestnut soils upon rice growing, as well as on the yield of rice and winter wheat. Three-year study has shown that the variant “green manure +10 t/ha (double dose) of phosphogipsum + deep subsoiling + MF” had the best impact on soil processes. The application of the full dose of phosphogipsum (5 t/ha), calculated for complete displacement of exchangeable sodium in cation exchange complex (CEC), was insufficient due to the presence of magnesium (over 20 % of CEC) which increased soil alkalinization in studied soils. Double dose of phosphogipsum supplied the increasing of calcium up to 79 % of CEC and decreasing of sodium and magnesium up to 3 and 18 % respectively. Thereby the soil structure and water resistance of soil aggregates have improved. Green manure and application of MF created the positive humus balance and increased the content of nutrition elements in soil in comparison with initial data (before soil reclamation). The yield increases of crops grown at the variants with full and double doses of phosphogipsum were 1.17-1.60 and 1.51-2.10 t/ha for rice and 0.79 and 1.13 t/ha respectively. Annual economic effect amounted to10.1 and 13.8 thousand rubles per hectare.