ECONOMIC AND ENVIRONMENTAL ASSESSMENT OF SOYBEAN GROWING IN THE WESTERN POLISSIA ZONE OF UKRAINE ON VARIOUS SOIL TYPES

Abstract

The results of experimental studies to establish the possibility and feasibility of growing soybeans on different types of soils in the Western Polissya zone are highlighted. It was established that when grown on sod-podzolic light loam soils with the application of complete mineral fertilizer in the norm N60Р60К60 and the use of the phosphorus-mobilizing preparation Rice Pi and the microbial inoculant of nitrogen-fixing action Rhizofix, the yield of soybeans of the ultra-early variety Junka of Canadian selection (Sevita Genetics) is – 4,03 t/ha. On peat soils with the application of complete mineral fertilizer in the norm N35Р60К90 and the use of the phosphorus-mobilizing preparation Rice Pi and the microbial inoculant of nitrogen-fixing action Rhizofix, the yield of soybeans was – 2,61 t/ha. The lower yield compared to sod-podzolic soils is explained by the less favorable hydrothermal regime on peat soils. The main limiting factor limiting soybean cultivation on peat soils is a shorter frost-free period compared to adjacent sod-podzolic soils. Also, peat soils, due to their high moisture content and low thermal conductivity, are cold soils, which slows down the growth and development of soybeans compared to adjacent sod-podzolic soils. In general, the issue of growing soybeans in peat soils requires further comprehensive study. It has been established that when soybeans are grown on a field with a by-product of 5,84 t/ha, 26 kg/ha of nitrogen, 19 kg/ha of phosphorus and 84 kg/ha of potassium are returned to the soil. On peat soils, when soybeans are grown on a field with a by-product of 4,34 t/ha, 20 kg/ha of nitrogen, 15 kg/ha of phosphorus and 63 kg/ha of potassium are returned to the soil. Provided that high-quality inoculation is carried out, up to 122 kg/ha of symbiotic nitrogen is accumulated when growing soybeans on sod-podzolic soils and 105 kg/ha on peat soils, which is equivalent to 300-350 kg/ha of ammonium nitrate. This amount of nitrogen is quite sufficient to meet the needs of subsequent crops in the crop rotation for this nutrient.