Optimizing the phosphate level of soils in agroecosystems of opolie regions of Central Russia

The regularities of the effectiveness of systematic application of phosphorus fertilzer in various types of crop rotations have been studied in long-term permanent field experiments on gray forest soils of opolie regions of Central Russia. The main factors determining the degree of use by crops of freshly applied and residual phosphates—the level of phosphorus fertilizer in agroecosystems, nitrogen supply of crops, and characteristics of phosphorus nutrition of the crops being grown—have been established. Depending on the character of interaction of these factors, crops over the course of 9 to 23 years have utilized 12–88% of applied fertilizer.