复合（混）肥中磷的形态及其在土壤中的作用

介绍磷酸盐的特性。提出在复合（混）肥生产中应合理配料，并控制好生产工艺，减少水溶磷在复合（混）肥中的退化。磷肥在不同类型土壤中的退化机理不同，大部分磷以金属磷酸盐和羟基磷灰石的形式储存在土壤中。磷在土壤中退化得很快，在一定的土壤和气候条件下，施用水溶性磷肥并非经济。在复合（混）肥生产中控制适当的水溶磷比例，既可满足作物生长的需要，又可减少土壤对磷的固定，提高施肥效益。

Phosphorus in compound fertilizers and its availability in soils

The properties of phosphates are described. In NPK production, a correct selection and mixing of raw material varieties is very important to avoid phosphorus degradation. There are different degradation mechanisms in different soils and most phosphorus are reserved in form of metal phosphates and hydroxyapatite. As a fast degradation, all soluble phosphates are not economic under certain soil and climate conditions. A proper percentage of soluble phosphates can meet the need of crops' growth, leading to a low fixation of phosphorus and a good return.