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用可降解材料包覆的控释肥料可以减少肥料损失及对环境的污染。以玉米淀粉、土豆淀粉、聚乙烯醇(PVA)为原料,在交联剂甲醛和增塑剂甘油的作用下,通过溶解、糊化、再交联等工艺过程,制得肥料包膜料液,用此料液制备了包膜尿素。考察了玉米淀粉∶土豆淀粉(质量比)以及用碱改性玉米淀粉对包膜尿素缓释性能的影响。结果表明,玉米淀粉∶土豆淀粉(质量比)=8∶2,总淀粉∶PVA=10∶9时,制备的包膜尿素缓释性能最好,用碱改性的玉米淀粉并不能提高包膜尿素的缓释性能。将包膜尿素进行土壤降解实验,发现该膜在土壤中完全降解时间为45d左右。此包膜材料缓释性能良好,具有成本低、可生物降解、无环境污染等特点。
Controlled release fertilizer coated with degradable material can reduce fertilizer loss and environmental pollution. With corn starch, potato starch, polyvinyl alcohol (PVA) as raw materials, under the action of cross-linking agent formaldehyde and plasticizer glycerin, through dissolving, gelatinizing, re-crosslinking and other technological processes, fertilizer coating liquid , Using this liquid preparation of coated urea. The effects of corn starch: potato starch (mass ratio) and alkali-modified corn starch on sustained-release properties of coated urea were investigated. The results showed that the prepared coated urea had the best sustained release performance when corn starch: potato starch (mass ratio) = 8: 2, total starch: PVA = 10: 9, and alkali modified corn starch did not improve the coating Slow release of urea. The urea-coated soil degradation experiment, found that the film completely degraded in the soil for about 45d. This coated material has good sustained-release properties, low cost, biodegradability and no environmental pollution.