Balance of nutrients in the agrocenosis of sugar beets under traditional and alternative fertilizer systems

Abstract

Goal. To study the impact of traditional and alternative fertilizer systems on the balance of nutrients in the soil and the formation of sustainable foundations for growing sugar beet. Methods. Long-term field — to determine the effect of fertilizers on the yield of sugar beets; analytical — to determine the content of nutrients in the components of the crop; calculation — to establish the removal of nutrients from plants and their balance in the soil. Results. The content and redistribution of nutrients in the components of the sugar beet harvest, their removal, and balance in the soil depending on fertilizer systems are shown. It was found that traditional organic and organo-mineral fertilizer systems formed a high positive balance of nutrients in the soil. An alternative system of fertilization with the introduction of straw, green mass of siderate and mineral fertilizers provided stable foundations for the cultivation of sugar beet. Conclusions. At the time of harvesting, sugar beet leaves contained 2.2–3 times more nutrients than root crops: nitrogen — 2.9–3 times, phosphorus — 2.2–2.3, potassium — 2.6–2.7 times for the absolute content of 2.26–2.30%, 0.52–0.53 and 2.50–2.54%. The application of 40 t/ha of manure + N90P60Kled to the maximum removal of nutrients from the soil: nitrogen — 230 kg/ha, phosphorus — 63, and potassium — 272 kg/ha. At the use of alternative fertilization, the largest removal was observed when applying straw + siderate + N90P60K90: nitrogen — 204 kg/ha, phosphorus — 56, potassium — 241 kg/ha. The removal of nutrients with root crops was greater than their removal with leaves: nitrogen — by 1.3 times, phosphorus — by 1.7, and potassium — by 1.5 times. The use of 40 t/ha of manure + N90P60K90 and 40 t/ha of manure contributed to a significant accumulation of nutrients in the soil at an intensity of nitrogen balance of 110–223%, phosphorus — 208–400, potassium — 111–204%. A self-supported balance of nutrients in the soil was achieved by applying straw + post-harvest siderate + N90P60K90 in the presence of leaf mass in the field: the intensity of nitrogen balance was 102%, phosphorus — 200, potassium — 97%. In the case of the removal of leaf mass in the soil, nitrogen, and potassium deficits and a positive balance of phosphorus were formed at balance intensities of 57%, 125, and 57%.