水基共聚物-粉煤灰沸石复合包膜尿素缓释机理及作物响应研究

How to achieve slow-release of nitrogen fertilizer, reduce nitrogen fertilizer loss and environmental pollution, and promote the quality and yield of crops are the key issues that urgently need to be solved in current agricultural production. This study will apply the compressive test and hydrostatic dissolution method, combined with scanning the electron microscope, infrared spectroscopy and other testing methods, in order to to analyze the compressive strength, dissolution rate, morphological structure and surface properties under the coupling of coating thickness, water-based polymer concentration, and particle size of coal-fly-ash zeolite, and also to establish the quantitative model of compressive strength and dissolution rate of the coated urea; Through the hydrostatic dissolution test and soil culture test, this study will clarify the medium concentration-temperature coupling effect and the water-nitrogen-temperature coupling effect on the kinetics and thermodynamics of dissolution and transformation of the coated urea, and also to establish the kinetic coupling model for urea dissolution and transformation; Combined with the field planting experiment, this study will explore the response mechanism of biological characteristics such as growth, photosynthesis, yield and quality of Chinese cabbage to water, nitrogen and temperature. Based on the principal component comprehensive evaluation method, this research aim to determine the suitable conditions for high quality and high yield of Chinese cabbage were determined. This project can provide the theoretical basis and technical support for improving the slow release mechanism of coated urea and optimizing parameters in the preparation technics of coated urea. It also can provide scientific basis and theoretical support for the rational application of coated urea and high-yield and high-efficiency cultivation of Chinese cabbage, which has important theoretical significance practical value.

如何实现氮肥缓释、降低氮肥损失、减少环境污染、促进作物优质高产是当前农业生产迫切需要解决的关键问题。本项目采用抗压试验和静水溶出试验方法，结合扫描电镜、红外光谱等测试手段，分析包膜厚度-水基共聚物浓度-粉煤灰沸石粒径耦合条件下包膜尿素抗压强度、溶出率、形貌结构和表面性质，建立包膜尿素抗压强度和溶出率量化模型；通过静水溶出试验和土壤培养试验，阐明介质浓度-温度耦合效应、水-氮-热耦合效应对包膜尿素溶出和转化动力学及热力学机制的影响，建立包膜尿素溶出和转化动力学耦合模型；结合田间种植试验，探究小白菜生长、光合、产量和品质等生物学特性对水氮热因素的响应机理，基于主成分综合评价方法明确小白菜优质高产的适宜条件。本项目能够为完善包膜尿素缓释机理和优化包膜尿素制备工艺参数提供理论基础和技术支撑，为包膜尿素合理施用和小白菜高产高效栽培提供科学依据和理论支持，具有重要的理论意义和应用价值。

高耗低效常规农业氮肥施用带来的资源浪费和环境污染问题，已成为我国社会发展迫切需要解决的痛点。包膜缓释技术的出现，为氮肥高效利用和农业污染防控带来新的途径。本文以废弃粉煤灰制备的沸石粉为基础原料，辅以生物降解性好和成模性优良的聚乙烯醇和聚乙烯吡咯烷酮等材料，提出了一种新型水基共聚物-粉煤灰沸石复合包膜尿素。探明了不同组分配比对膜材缓释、亲水、力学、微观形貌等物化特性影响，揭示了水基共聚物浓度-沸石粒径-包膜厚度三种工艺参数对包膜尿素颗粒抗压、缓释、微观形貌等物化特性影响，分析了土壤模拟溶液浓度-温度耦合效应对包膜尿素颗粒静水溶出特性影响，探究了水分-施氮量-温度条件下土壤包膜氮肥转化特性，为完善包膜尿素缓释机理、优化包膜尿素制备工艺、降低生产成本、提高包膜缓释性能提供重要的理论基础和技术支撑。基于盆栽种植试验，揭示了不同水氮热条件下施用包膜尿素对生菜生长生理及产量品质形成影响，明确了生菜优质高产模式，为包膜尿素合理施用和作物高产高效栽培提供科学依据，为其下一步田间应用推广奠定良好的理论基础。