生产实践与科学研究业已证明,磷肥在石灰性土壤上有着明显的增产效果。但其利用率远较氮肥为低,一般不超过25％。磷肥利用率低的原因,主要在于土壤对磷的固定作用。所谓土壤的固磷作用,指土壤中各种含磷化合物,从可溶性或速效性状态转变为不溶性或缓效性状态而言。 Production practice and scientific research have proved that phosphate fertilizer has obvious yield increase effect on calcareous soil. However, its utilization rate is far lower than nitrogen fertilizer, generally not more than 25%. The reason for the low utilization rate of phosphate fertilizer lies mainly in the fixation effect of phosphorus on soil. The so-called soil phosphorus fixation refers to a variety of phosphorus-containing compounds in the soil, from soluble or fast-acting state to insoluble or slow-acting state.