Agroecological and economic assessment of organic crop rotation in Polissia zone

For the organic production of plant products on sod-podzolic soil, a biologized short-rotational grain rotation was put to study: sorghum–oats–oats– vicot–oats–barley. In conditions of shortage of manure, the optimization of the nutrition system is carried out due to the by-products of grain and leguminous crops, oil radish siderate, the use of foliar treatment of crops with preparations of biological origin (microfertilizer Avatar, biopreparation BiocomplexBTU and liquid biofertilizer Volynski humaty), including, in the background mineral fertilizers allowed in organic production (P40K60 — phosphorite flour and potassium sulfate). The goal of the task was to investigate the influence of the biological fertilization system on crop rotation productivity, grain quality, soil fertility, and the economic efficiency of crop cultivation. It was established that, on average, during the 2021–2023 research, the maximum grain yield indicators were obtained for all factors of influence: pea-oats — 2.25 t/ha, oats — 1.88, vetch-oats — 1.66 and barley — 1.61 t/ha, the total crop rotation productivity under these conditions was 2.28 t grain units. It was determined that the protein content of oat grains was 9.1–9.8%, barley — 10.8–11.7%, the protein content of flax seeds was at the level of 18.2–19.0%, vetch — 22.9–23.8%, the lowest indicators were noted in the control. It has been established that in biological crop rotation due to 50% saturation with leguminous crops against the background of straw and siderate, a deficit-free balance of humus and nutrients is achieved. Due to the by-products of crops, 175 kg of humus accumulates in the soil annually, which ensures a simple reproduction of its fertility, and the additional application of fertilizers of biological origin helps to increase the humus to 350 kg, which ensures an extended reproduction of the fertility of sod-podzolic soil. Nitrogen comes at the expense of oil radish siderate, with by-products of leguminous crops and is biologically fixed from the atmosphere. Removal of phosphorus and potassium by crops is compensated by the supply of these elements with straw and siderate. Due to the disparity of prices, the cultivation of grain crops was unprofitable under all factors of influence, the profitability of legumes was 19.6–64.4%. The level of profitability of the general crop rotation for the treatment of crops with drugs was 6.5–14.8%, and the costs incurred for the purchase and application of phosphorus-potassium fertilizers did not pay off with the growth of crop yields.