Effect of the Use of Phosphorus Fertilizer on the Variation of Crop Yield Increments1 in the Conditions of the Trans-Urals

The variability of crop yield growth from the use of phosphorus fertilizer in doses of P40–20 added to nitrogen fertilizer in a 52-year stationary experiment of the Kurgan Research Institute of Agricultural Sciences is shown. The study of the effectiveness of phosphorus was conducted first in the grain crop rotation during annual plowing, then in permanent wheat crops after a stubble background. The yield increases were very different over the years. With a few exceptions, the relationship of the increase in yield from phosphorus with the air temperature of the 1st decade of June is shown. High increases were accompanied by low air temperature in the 1st decade of June and sufficient provision of plants with moisture. The connection with precipitation was more clearly manifested in permanent wheat crops. The payback of the P40 dose by the increase in yield in grain units in crop rotation in years with high fertilizer efficiency was at the level of 8–14 kg/kg, falling in other conditions to 6–1.5 kg/kg. The payment of P20 by increments of permanent wheat grain varied from 13–17–26 kg/kg in years with high and medium increments up to 2 kg/kg with low effects from the use of phosphorus fertilizer.