Nutritional regime of gray forest soil аt different anthropogenic loads

Abstract

The aim of the research is to establish the peculiarities of the formation of the nutrient regime of gray forest soil with different systems of basic cultivation, fertilization and sealing of by-products of crops in short-rotation 4-field grain crop rotation – winter wheat–corn for grain–barley–soybean. Evaluate the quantitative inflow of biomass, participation in the formation of the nutrient regime of gray forest soil, especially the differentiation of 0–40 cm of soil layer depending on the distribution of nutrients in different tillage soil systems. The studies were carried out in a long-term stationary experiment of the department of soil cultivation and weed control of the NSC «Institute of Agriculture of the NAAS», founded in 1969. The fertilization system consisted of the application of mineral fertilizers N65Р58К68 kg acting things per 1 ha of crop rotation area. As an organic fertilizer, we used by-products of crop rotation, where during 2009–2013 received an average of 5,17–5,50 t/ha, and 2014–2017 – 6,65–7,76 t/ha of crop rotation. The existing yield of the main product significantly influenced the volume of the non-commodity part, with the growth of the main product, the growth of by-products also took place in direct proportion. Nitrogen removal averaged 105 kg/ha, and with biomass it returned on average 55,4 kg/ ha, nitrogen with a full mineralization cycle, in general, this corresponds to 45–47 % of the share of costs. In general, the return of phosphorus from by-products for the rotation of 5 received an average of 12,0–16,7 kg/ha and 4-field crop 26 rotation 19,5–22,0 kg/ha, which was 35–40 % of the total removal harvest. The soil received many times more potassium from the biomass of agricultural crops than part of the cost of the main product, due to the attraction of the maize leaf mass, from which an average of 177–253 kg/ha enters the soil, and for crop rotation – 61,4–95,4 kg/ha per hectare of sown area. Key words: gray forest soil, soil nutrient regime, recycling of nutrients, main and by-products of crops.