Effect of fertilizers on the NPK balance in the 10<sup>th</sup> rotation of the beet crop rotation in the Сentral Сhernozem Region during the plowing of by-products and their alienation

Prolonged fertilization without embedding crop rotation byproducts in the soil did not contribute to the creation of a positive NPK balance in most experimental variants (except for K2O in variants N90P90K90 + + manure 25 t/ha, N135P135K135 + manure 25 t/ha and N120P120K120 + manure 50 t/ha and P2O5 in variant N190P190K190). Sealing of straw and sugar beet tops created a positive NPK balance in almost all experimental variants, since the soil received 17.5–26.8% more nitrogen, 18.1–44.9% more P2O5 and 18.2–41.7% more K2O than without sealing. An increase in fertilization increased the intensity of the balance (during the incorporation of by-products) due to an increase in the share of by-products in the crop, the intensity of the K2O balance increased most of all. Against the background of by-product sealing, the highest intensity of the NPK balance was noted in the N120P120K120 + manure 50 t/ha variant.