化学合成型缓释NPK肥养分释放调控机制的研究

鉴于化学合成型缓释NPK肥具有集多种营养元素于同一分子链、养分利用率高、合成工艺简单、工艺流程短、反应条件温和等优点，其研制和应用已成为缓控释肥领域中的重要研究方向之一。在前期的研究中，已明确了化学合成型缓释NPK肥具有优良的养分缓释性能，大分子链中的养分元素经过断键分解才能释放，且不同酸碱度、土壤条件对其养分释放影响显著，但影响其养分释放的机制还不清楚。本项目拟通过研究无机酸碱催化、酶催化及土壤条件对化学合成型缓释NPK肥中大分子断键位置、基团变化和养分离子转化的作用过程，探明含有营养元素的大分子是如何从水不溶状态向水溶状态转化以及水溶后的大分子又如何转化为能被植物吸收的养分离子，并研究分子特性对养分释放的影响以及养分释放调控的机制，揭示化学合成型缓释NPK肥养分释放及调控的机制，为进一步提高化学合成型缓释NPK肥的养分利用率提供理论和技术支撑。

The development and application of chemically synthetic slow release NPK fertilizer has become a hot research topic in the field of slow release fertilizer due to its advantages on variety of nutrients set in the same molecular chain, high nutrient use efficiency, simple synthetic procedure, short process and mild reaction conditions. Our preliminary research indicated that such NPK fertilizer shows excellent nutrient release properties, and the essence of nutrient release is significantly different in different pH and soil conditions. However, the mechanism of nutrient release of chemically synthetic slow release NPK fertilizer is not well understood. The proposal of the current application is to (1) characterize the process of molecular bond breaking, group changes, and transformation of nutrient ions of the chemically synthetic slow release NPK fertilizer by inorganic acid, enzyme and soil condition; (2) understand how macromolecules with nutrients is transformed from water-insoluble to water-soluble and how the water-soluble macromolecules can be converted into the nutrients that may be absorbed by plants; and (3) investigate the effect of molecular characteristics on nutrient release and regulation to reveal the mechanism of nutrient release and regulation from the chemically synthetic slow release NPK fertilizer. The proposed research will ultimately provide both theoretical and practical technology to improve the nutrient utilization of chemically synthetic slow release NPK fertilizer.