聚合物/膨润土复合控释材料的应用研究

Study on the use of polymer/bentonite composites for controlled release

用聚合物/膨润土复合材料与肥料混合制备混合型缓/控释肥和用复合材料包裹尿素制备包膜型缓/控释肥进行盆栽试验。结果表明,聚合物和膨润土都具有控释作用,二者复合具有更好的控释效果。几种混合型缓/控释肥处理的玉米生物量均较对照有显著提高,以添加含膨润土0 5倍(相对于聚合物质量)的复合材料配制的缓/控释肥效果最好。几种包膜型缓/控释肥处理的玉米生物量较对照有所提高,差异达显著水平,以含膨润土2倍的复合材料制备的缓/控释肥效果最好。

Controlled release technology has emerged as a potential approach to settle the problems associated with the application of conventional fertilizers. Great advances have been made on the use of polymers as controlled release materials for slow-release fertilizers. Swelling polymer can absorb lot of water from aqueous solution and swell at the same time,therefore it has been applied in many fields, e.g. medical treatment, water treatment, agriculture and other relevant fields. Polyacrylamide hydrogels and its derivatives are used in agriculture as carriers of agrochemicals and soil (conditioners). Polymer/bentonite composites were used as controlled release materials in this study because of its lower production cost and better purpose for controlled release. Polymer/Bentonite composites were prepared with acrylamide and bentonite by polymerization. The mass of Bentonite in the composites 0B, 0.5B, 1B, 2B are 0, 0.5, 1, 2 times more than the polymer, respectively. Mixed controlled release fertilizers (MCRFs) were prepared by mixing polymer/bentonite composites with fertilizers. The MCRFs 0M, 1M, 2M, 3M, 4M were made of bentonite, 0B, 0.5B, 1B, 2B mixing with fertilizers, respectively. Coated controlled release fertilizers (CCRFs) were prepared by coating urea with polymer/bentonite composites. The CCRFs 0U, 1U, 2U, 3U, 4U were made of bentonite, 0B, 0.5B, 1B, 2B mixing with fertilizers (respectively). Both MCRFs and CCRFs were used for pot experiments. The results showed that both polymer and (bentonite) were of controlling release function, however, the function of controlling release of composites was better. In MCRFs (pot) experiments, (corn) biomass of MCRF treatments increased markedly compare with CK with the best amount being 2M MCRF. The recovery of N, P, K in MCRF treatments were higher than that in CK. In CCRFs pot experiments, corn biomass of CCRFs treatments increased markedly compare with CK with the best treatment being 4U. The different reached a significant level. The recovery of N in CCRFs treatments were higher than in CK.