复合控释材料的控释性能、肥效及其成膜特性研究

膨润土和木素制成复合控释材料用于包膜控释肥。电镜扫描研究表明,复合材料包膜厚度明显比单用膨润土处理薄,且膜孔隙量少,粒间堆积较紧密。土柱淋溶试验表明,膨润土及其复合材料包膜尿素50 d的氮素累积溶出率远低于普通尿素,三种包膜尿素处理分别比普通尿素降低8.61、14.01、15.22个百分点。两种复合材料包膜处理氮素累积溶出量分别比单用膨润土包膜处理降低11.31%、13.83%。盆栽、大田小区试验表明,复合材料包膜尿素可明显提高作物产量及氮肥利用率。膨润土与木素复合用作控释材料在研制适合我国国情的农用控释肥方面是可行的。

RELEASE-CONTROLLING COMPLEX MATERIAL'S CAPABILITY, FERTILIZER EFFICIENCY AND COATING CHARACTERISTICS

Bentonite and lignin were blended and prepared into a kind of releasing-controlling material, which was then used as coating for manufacture of coated-controlled-release fertilizer. The scanning electron photomicrographs showed that the coating was thinner, with fewer cracks and more compact intergranular deposit than the coating of mere bentonite. The soil column leaching test indicated that the cumulative N leaching rate of the urea coated with either bentonite or the complex within 50 days was much lower than that of common urea. In three coating treatments, it decreased by 8.61%, 14.01% and 15.22%, respectively, in comparison with CK, common urea. The total N leaching of the two treatments using complex materials as coating was 11.31%, 13.83% lower than the treatment using bentonite as coating. The pot and field trials also showed that application of urea coated with either complex could significantly increase crop yield and N recovery rate, suggesting that it is advisable to use. The mixture of bentonite and lignin as coating material, which suits the conditions of the country in developing controlled-release fertilizer.