Influence of ecological and agrochemical factors on the level of soybean yield

Abstract

The article presents the results of studies on the effectiveness of the use of mineral and organic-mineral fertilizer systems in a long-term stationary 5-course soy-grain crop rotation depending on agro-ecological factors. The goal of research is to study the effect of long-term application of mineral (annually N42 P48 kg of active ingredient / ha of crop rotation area) and organic-mineral (annually N24 P30 kg of active ingredient + 4.8 t of manure per 1 ha of crop rotation area) fertilizer system on the productivity of soybean in crop rotation. The objects of research were mid-ripening and early-ripening soybean varieties, preceding crops - annual grasses (soy-oat mixture) and spring wheat. The preceding crops, variety and hydrothermal conditions under which soybean was grown from 1963 to 2017 were considered as agro-ecological factors. It was established that the highest yield of soybean was obtained when placing soybean crops after wheat, while by the number of years, the yield level of 1,8 – 2,0 t/ha was repeated 16 % more often than when growing soybean after annual grasses. The maximum increase in yield relative to the control (0, 17 t/ha) was formed by the long-term use of organic-mineral fertilizer system for soybean cultivated after wheat. In cold wet years, the use of organic-mineral fertilizer system ensured plant resistance to unfavorable weather conditions, stimulating an increase in the soybean yield relative to the control by 0,18 t/ha. The most responsive to fertilizer application were the mid-ripening soybean varieties: the increase in grain yield amounted to 0,03 – 0,20 t/ha relative to the control, and the realization of potential yield of the variety increased by 2–7 %.