The nutritional regime of the soil and the nitrogen status of plants in the grain-fallow and fruitshifting crop rotations

Abstract

The main agrotechnical significance of crop rotation is that each crop is placed in the best conditions for its growth and development and at the same time prepares good conditions for the next crop in the crop rotation. Under optimal cultivation conditions and a high level of mineral nutrition, the grain yield of modern wheat varieties reaches 18.4 c/ha. In real economic conditions, when high prices for mineral fertilizers limit their use, the yield of spring wheat grain in the Kostanay region is 11.2 c/ha. In the experiment, 2 types of crop rotations were studied — 4-course grain-fallow (fallow— wheat — wheat — wheat) and 4-course fruit-shifting (peas — wheat — oilseed flax — wheat). On each crop rotation variants with different levels of mineral nutrition were laid — without fertilizers (control) and P15. Seeding rate of agricultural crops (million/ha of germinating seeds): spring wheat — 3.0; peas — 1.0; oilseed flax — 6.0. The experiment adopted the technology of tillage — No-till with elements of precision farming. All records and observations were carried out according to standard methods. The analysis of the dynamics of the food regime of the soil indicates that the best conditions for mineral nutrition of plants are created when placing crops in a grain-fallow crop rotation, which includes herbicidal steam with long-term annual application of mineral fertilizers. Thus, in the soil layer of 0–40 cm on the first wheat after fallow, the content of nitrate nitrogen was characterized as average and amounted to 11.9–12.8 mg/kg, the content of mobile phosphorus had increased and amounted to 121 mg/kg of soil. In terms of the effectiveness of the use of options for the purpose of regulating the food regime, it is necessary to distinguish all three wheat fields in the grain-fallow crop rotation. Here, the highest indicator in the earing phase — above the control by 6.1–14.7% — was in variants with the use of fertilizer in rows.