The experiment took the fly ash and superfine phosphate powder as the coated material,and made two kinds of coated slow-release urea(CSRU) with different coating thickness to study the effects on the growth of Chinese cabbage in field experiments.The experiment results showed that coated slow-release urea could significantly increase the plant biomass,photosynthetic rate,transpiration rate,total N,P and K,POD,SOD and CAT activity than those of CU,and other indicators were no less than those of CU.Different ...