麦饭石混合物包膜尿素的肥效及成膜理化特征研究

Fertilizer efficiency of Maifan stone coated urea and its film-forming physical-chemical properties

以麦饭石和有机粘结剂为包膜材料,采用开放式旋转包膜工艺,制得麦饭石混合物包膜尿素(简称包膜尿素).盆栽试验结果表明,施用包膜尿素玉米生物量显著高于尿素对照,氮素利用率提高13 ～ 32个百分点; 应用红外光谱对包膜尿素膜层结构的研究结果看出,膜层结构发生较大的变化,出现了新基团并发生了峰形变化; 通过电镜扫描技术对膜结构的研究结果显示,麦饭石包膜前后的结构差异明显,包膜前为分散的单个颗粒,而包膜后是固体粉末颗粒间紧密排列并通过液体胶联的多层堆叠而形成包膜层,这些变化是麦饭石包膜尿素的膜层结构紧密而使其控释性能增强的原因.

The fertilizer efficiency of a newfashioned coated urea, coated with Maifan stone and organic agglomerant by means of the open and rotating coating-craft, and its film-forming physical-chemical properties were studied. Pot experiment results showed that Maifan stone coated urea significantly increased the biomass comparing to the control （single application of conventional urea） and the nitrogen utilization ratio increased by 13 %-32 %. Analysis results on the coating layer structure of Maifan stone coated urea using FT-IR indicated that there was a big structure change. New radicals appeared and peek shape changed. The film structural characteristics were also observed using scanning electron microscope. Results indicated that there was a big difference on the structure of Maifan stone between before and after coating. Maifan stone existed as separate single particles before coating, but after coating, these single particles were closely arranged, moreover, they were piled on by liquid glues forming a film. These changes gave rise to a more compacted film structure, which resulted in a better controlled-release capability of Maifan stone coated urea. Maifan stone, as a coating material, was worthwhile to ulterior study due to its low price and good performance.