High-analysis compound fertilizer is oversupplied in the market for its higher price and unsuitable formulae. 随着高浓度复合肥数量在市场上的递增，一些地区因其所销肥料产品养分固定，价位较高，而出现过剩。
With calcium chloride precipitant to eliminate the interference of PO43-, total nitrogen in compound fertilizer is determined by formol method. 用氯化钙作沉淀剂，消除磷酸根离子的干扰，用甲醛法测定复合肥中的总氮。
