将尿素分别与膨润土、硅藻土、凹凸棒土等3种非金属矿物复合,再以乙基纤维素(EC)外包膜得到新型尿素包膜缓释肥,采用XRD、IR、SEM等手段表征了矿物及缓释肥的微观结构与形貌。以土壤动态淋洗实验考察了包膜肥的氮素释放特征,探讨了矿物载体种类、非金属矿物/尿素配比、二次包衣增重率等因素对缓释性能的影响。研究结果表明:3种非金属矿物相比,凹凸棒土对尿素具有较优的缓释效果。当凹凸棒土/尿素质量比为9∶1和8∶2时,缓释效果较好。EC包衣增重10%~12%时,凹凸棒基缓释肥在24 h内氮素溶出率小于20%,28 d累积溶出率小于80%,符合国家规定的缓释肥相关技术指标。XRD表征显示凹凸棒土与尿素复合后,并未改变凹凸棒土载体的晶体结构;IR表征显示凹凸棒土、尿素与EC三者之间存在较强的超分子作用;SEM表征显示包膜后的样品由针状结构堆积包覆而成,针状结构堆积形成的微孔有助于尿素的缓释;外层EC膜能遇水溶胀,对凹凸棒土中淋失的尿素形成阻滞层,因此包膜后的尿素缓释肥具有缓溶、长效、保氮等特性。 The urea was mixed with three kinds of nonmetallic minerals such as bentonite, diatomite and attapulgite respectively, and then a new type of urea coated slow-release fertilizer was obtained with ethyl cellulose (EC) coating. XRD, IR, SEM and other means Characterization of the mineral and slow-release fertilizer microstructure and morphology. Soil dynamic leaching experiments were conducted to investigate the characteristics of nitrogen release from coated fertilizers. The effects of different types of mineral carriers, nonmetal mineral / urea ratio, weight gain of secondary coating on sustained release properties were discussed. The results show that attapulgite has better sustained-release effect on urea than the three non-metallic minerals. When attapulgite / urea mass ratio of 9: 1 and 8: 2, the slow release effect is better. The results showed that the dissolution rates of attapulgite-based slow-release fertilizer within 24 h were less than 20% and the cumulative dissolution rates at 28 days were less than 80% when EC coating weight was increased from 10% to 12%, which accorded with the relevant technical indicators of slow-release fertilizer stipulated by the state. XRD characterization showed that the composite of attapulgite and urea did not change the crystal structure of attapulgite. The IR characterization showed that there was a strong supramolecular interaction between attapulgite, urea and EC. SEM characterization showed that Of the sample by the needle-like structure deposited from the accumulation of needle-shaped structure of the accumulation of micro-pores contribute to the slow release of urea; outer EC film can swell water, attapulgite leached urea to form a retardation layer , So coated urea slow release fertilizer with slow-dissolving, long-lasting, nitrogen and other characteristics.