Nutrient balance and productivity of crop rotations as affected by their structure and fertilisation

Purpose. To investigate the influence of fertilisation systems on the productivity of short crop rotations and the formation of the balance of nutrients in the soil. Methods. Long-term field and analytical. Results. The productivity of crop rotations and the balance of nutrients in the soil depending on their structure and fertilisation systems are presented. It was established that organic-mineral fertilisation systems formed the highest fodder productivity of crop rotations and the best indicators of the balance of nutrients in the soil. Conclusions. Application of N53Р42K42 + 6.7 t of manure per 1 ha of arable land in crop rotation provided the highest fodder productivity of 9.2 t/ha with an advantage over control without fertilisers of 3.8 t per 1 ha of crop rotation area. The application of conventional and alternative organic-mineral fertilisation systems was determined to be effective in row crop rotation: the productivity of crop rotation was 8.4 and 8.3 tons of fodder units per 1 ha of crop rotation area, respectively. Organic-mineral fertilisation systems formed an optimal balance of nitrogen in grass and grain and row crop rotations with the intensity of the balance of 94–95% and 100–103%, respectively. In the grain and row crop rotation, the nitrogen balance was negative at the intensity of 82–84%. In all crop rotations, the combined application of organic and mineral fertilisers contributed to the accumulation of phosphorus in the soil and formed a positive phosphorus balance at an intensity of 103–115%. None of the fertilisation systems provided a positive balance of potassium in the soil. The best indicators of potassium balance in crop rotations were formed by applying N53Р42K42 per 1 ha of arable land + by-products with a potassium deficit of 33–41 kg/ha of the crop rotation area and the intensity of its balance of 73–78%.