以往施用低浓度的普通过磷酸钙时,土壤并没有缺硫问题,而这几年改用高浓度的重过磷酸钙以后,某些地区却出现了土壤缺硫现象。这是为什么呢?要弄清这个问题还得从普通过磷酸钙和重过磷酸钙的成分说起。普通过磷酸钙的主要成分是磷酸一钙,肥料中含磷14%~l8%,副成分为硫酸钙,占50%左右。因此,施用普通过磷酸钙不仅能为作物提供磷营养,而且还可使作物获得硫 In the past, the application of low levels of ordinary superphosphate did not cause sulfur deficiency in the soil. However, in recent years, the use of high levels of SSPG has led to sulfur deficiency in some areas. Why is this? To clarify this issue have to start with the general composition of superphosphate and superphosphate. Ordinary superphosphate calcium phosphate is the main component of a calcium, phosphorus fertilizer 14% ~ l8%, deputy component of calcium sulfate, accounting for about 50%. Therefore, the application of common superphosphate not only provides phosphorus nutrition for the crop, but also makes the crop obtain sulfur