在深入开展农业学大寨、普及大寨县的群众运动中,发动群众,广泛普查,开辟新的磷肥来源.是当前的一项重要任务。我市通过开展普查含磷土和低品位磷矿的群众运动,大大改变了土壤缺磷的状况,并出现了许多增产事例。到目前不完全统计,全市区施含磷土的面 In deepening the agricultural science Dazhai and popularizing Dazhai’s mass movement, mobilizing the masses, extensively surveying and opening up new sources of phosphate fertilizer is an important task to date. The mass movement of the city through carrying out census of phosphorus-bearing soils and low-grade phosphate rock has greatly changed the situation of phosphorus deficiency in the soil and many cases of yield increase have emerged. To the current incomplete statistics, the city’s facilities containing phosphorus surface