The calculations of the balance of nitrogen, phosphorus and potassium in the soil under sugar beet are given for an average of three years of research, depending on the doses of mineral and organic fertilizers for mineral, organic and organo-mineral fertilizer systems in crop rotation on podzolized black soil.
Research has shown that in the case of the mineral fertilizer system, the removal of nitrogen by crops and their by-products exceeds its intake with fertilizers by 68–91 kg / ha. The positive nitrogen balance in the soil (22–48 kg / ha) was revealed when applying 45 and 60 t / ha of manure under sugar beets, and also 30 t / ha of combined manure and mineral fertilizers in a dose of N60P135K30 – 31 kg / ha and 45 t / ha of manure + N90P202K45 – 43 kg / ha. The intensity of the nitrogen balance was higher (119%) when applying 60 t / ha of manure under sugar beets, and its utilization coefficient with mineral fertilizers in the dose of N135P135K135 was 76%. Regardless of the doses and systems of sugar beet fertilization, the phosphorus balance in the soil was positive (34–225 kg / ha), and its intensity was 161–350%.
The positive balance of potassium in the soil (36–98 kg / ha) was revealed when applying 45 and 60 t / ha of manure under sugar beets, and also 45 t / ha of combined manure and mineral fertilizers in a dose of N90P202K45 – 8 kg / ha. The intensity of the potassium balance was higher (90–137%) with the organic fertilizer system, and its utilization coefficient with mineral fertilizers was 86% when applying N135P135K135.
The capacity of nitrogen, phosphorus and potassium balance in podzolized black soil increased when doses of fertilizers had been increased and was highest in the variant with the application of 45 t / ha of manure + N90P202K45 respectively 587, 405 and 622 kg / ha.
Depending on the doses of mineral and organic fertilizers, nitrogen removal from the soil was 48–116 kg / ha, phosphorus – 9–27 kg / ha and potassium – 71–161 kg / ha. When using sugar beet tops as a manure, the balance of nutrients in the soil improved. At the same time, the intensity of balance increased in nitrogen by 39–94%, phosphorus by 58–150, and potassium by 44–163%.
Key words
sugar beets, nutrient balance, manure, mineral fertilizers, nitrogen, phosphorus, potassium.