Ecological and economic indicators of short crop rotations on drained soils in the conditions of climate change
Aim: To establish the influence of a complex of factors on productivity of short crop rotations with the cultivation of commercially attractive crops, the reproduction of soil fertility is based on optimized agrochemical supply by replacing litter manure with by-products in the conditions of low moisture supply drained sod-podzolic soils.
Methods: Field, statistical, laboratory methods.
Results. We found that the productivity of crop rotations depends on their saturation with corn, which, on average, in 2016–2020, at the recommended (N60P60K60) and increased rates of mineral fertilizers (N90P90K90) on the background of manure or by-products of precedents, had a grain yield levels of 6.04–7.66 t/ha. The highest yield of grain from 1 ha of crop rotation area was obtained in the three-field crop rotation (soybean–corn–corn) from 66.6% of corn–from 3.14 tons for control, to 6.05 tons–at high rates of mineral fertilizers (N62P86K90+by-product). Productivity of three-field (field pea-oats–winter triticale–corn) and four-field (lupine–winter rape–winter rye–corn) crop rotations with a share of corn of 33.3% and 25%, ranged from 2.43 tons to 4.52 tons of grain, respectively. Crop rotation without corn (soybeans–winter wheat–sunflower–buckwheat) had overall productivity of 50% less.
Conclusions: Combining the recommended N42P57K60 and the increased N62P86K90 norm of mineral fertilizers with by-products in all crop rotations promotes the formation of expanded reproduction of humus in the soil. Deficient nitrogen balance was manifested only with the introduction of N42P57K60 against the background of 10 tons of manure per 1 ha of crop rotation area. The most effective in all crop rotations is the organo-mineral fertilizer system N42P57K60 on the background of by-products, which provided a 27.9–36.5% profitability level. Each crop rotation is dynamic and can be recommended for production, depending on the farm's market conditions and economic capacity. As for the choice of feed system with mineral fertilizers, each in itself may be acceptable. In the absence of livestock farms, an alternative to manure is using by-products of all crops, which does not reduce crop productivity, profitability and increases soil fertility.