Duration of the Aftereffect of Mineral Fertilizers in the Experience of the Kurgan Research Institute

The effect of nitrogen-phosphorus fertilizer for 5 rotations of a 4-field grain crop rotation in the stationary experiment of the Kurgan Research Institute was studied. Different nitrogen distribution between crop rotation crops was tested. When the entire crop rotation dose of nitrogen was applied to the first field, the fertilizer had an aftereffect on the yield of the next 3 crops. Similarly, when dividing the nitrogen dose into the 1st and 3^rd fields, an increase in crop yields was noted in the 2^nd and 4^th crops. The different distribution of nitrogen between crop rotation crops gave similar effects under experimental conditions with the manifestation of the advantage of using nitrogen in crop rotation in a year. For the next 27 years, fertilizers were not applied on these backgrounds and the aftereffect of fertilizer applied in total doses of N1050–1575P840 for 21 years was taken into account in permanent wheat crops. At the 1^st dose of nitrogen, the fertilizer had a significant aftereffect for 5 years, at the 2^nd – 9, but also later. In years with sufficient moisture, an increase in yield was observed from the aftereffect of nitrogen-phosphorus fertilizer.