... a kind of granular solid fertilizer consisting of nitrogen (N), phosphate (P2O5), kalium (K2O) and many medium and trace elements (e ... .g. iron, magnesium, zinc, boron, manganese, etc). Its processing formula can be designed according ... Varieties of commonly used compound (mixed) fertilizers (proportion of nitrogen, phosphate and kalium): 10-0-10, 12-12-0,0-8 ...