大寨大队从1958年开始施用过磷酸钙。最初直接将磷肥用作追肥,肥效很低,接着将磷肥和有机肥混合施用,效果也不理想,后来将磷肥和厩肥(猪、牛、骡、马、羊粪等)及人粪尿混合发酵沤制后施用,显著提高了肥效。因为经过混合堆沤后,有机肥就能大量吸附磷肥,减少了石灰性土壤对磷的固定作用,有利于作物吸收。沤制时难溶性 Dazhai brigade since 1958 administered superphosphate. The first direct use of phosphate fertilizer as fertilizer, fertilizer efficiency is very low, then the phosphate and organic fertilizer mixed application, the effect is not satisfactory, and later phosphate and manure (pigs, cattle, mules, horses, sheep manure, etc.) and human excrement mixed fermentation After the system is applied, a significant increase in fertilizer efficiency. Because after mixing piles, organic fertilizer can be a large number of phosphate fertilizer, reducing the calcareous soil phosphorus fixation, is conducive to crop absorption. System is difficult to dissolve system