The structure of fertilizers was studied by scaning electronic microscopy ( sem ) , and the nutrient release characteristics were studied using water dissolution rate method and soil column leaching method . [ result ] the 24 hours n water dissolution rates of sapcus were 18 . 22 % - 83 . 87 % , and n accumulated leaching rates in four weeks were 40 . 91 % - 65 . 38 % , which decreased by 5 . 21 % - 40 . 68 % compared with that of urea under the same experiment conditions 方法以不同类型和吸水倍率的高吸水性树脂为包膜材料,以大颗粒尿素和改性矿物包膜尿素为原料肥料,研制出高吸水性树脂单层包膜尿素、高吸水性树脂复式包膜尿素系列产品,利用电子扫描电镜研究了其结构特征,并以水中溶出率法和模拟土柱淋溶法研究其养分释放特性。