The effect and aftereffect of mineral fertilizers on spring soft wheat in a long-term experiment on the southern chernozem of the Povolzhye steppe zone

In a long-term stationary experiment on the Southern Chernozem of the Volga steppe, the ninth rotation of the six-field grain-pair crop rotation is being completed. The experimental material accumulated over these years (1968 – 2023) made it possible to identify the features of the action and aftereffect of nitrogen-phosphorus fertilizers on spring wheat (the third field of crop rotation). It was found out that the highest grain yield increases from the direct action of fertilizers were obtained in conditions of a humidified growing season. In arid conditions, the effect of fertilizers decreased. Increasing the nitrogen dose from N60 to N80-90 was ineffective. It is also proved that nitrogen and phosphorus fertilizers applied under the previous crop (winter wheat) had a positive aftereffect on spring wheat. The amount of increases also depended on the moisture availability of the growing season. The hydrothermal conditions of May and June play an important role in the formation of the grain harvest of spring wheat in the arid chernozem steppe.