【作者】 邹洪涛；

【导师】 张玉龙；

【作者基本信息】 沈阳农业大学 ， 农业环境与生态， 2007， 博士

【摘要】 生产和使用环境友好型包膜缓释肥料是目前化肥工业发展的主要趋势之一，也是发展现代农业、实施可持续发展战略的必然要求。本文着眼开发高效、环保、低成本的包膜缓释肥料，选用环境友好、廉价的聚乙烯醇-淀粉交联液和来源广泛的硅藻土（或沸石粉）的共混物作为颗粒肥料包膜材料，使用转鼓工艺制成了有机无机复合物包膜缓释肥料；对该有机无机复合物包膜肥料的保肥、控肥效果及其机理进行了系统研究，内容涉及膜材料的耐水性、有机高分子聚合物适宜浓度的选择以及包膜后肥料养分控释机理、环境友好性及田间应用效果等多个方面，得出主要结论如下。1．甲醛、硼砂和尿素均能提高聚乙烯醇-淀粉交联液成膜的耐水性；但经尿素改性的膜材料吸水率最低，更适合用作提高聚乙烯醇-淀粉交联液耐水性的改性剂。2．土柱淋洗试验结果表明，在包膜材料与被包膜肥料数量比例一定的条件下，经尿素改性后聚乙烯醇-淀粉交联液与硅藻土（或沸石粉）两种原料比例适当，混合制成包膜材料生产出的包膜肥料养分缓释效果最好：本文找出了这一两种原料的适宜比例。3．包膜缓释尿素的氮素释放过程可以用一级反应动力学方程N₁=N₀[1-exp（-kt）]描述，其释放速率常数k随着温度升高、土壤含水量增加、水蒸气压差增大而增大；包膜肥料内外水蒸气压差是致使养分释放的直接原因，温度、土壤含水量等都是通过影响膜内外水蒸气压差的变化而影响养分释放速度的。4．扫描电镜试验表明，包膜材料不同，包膜后在肥料颗粒表面成膜的结构不同，聚乙烯醇-淀粉交联液与硅藻土混合成膜的结构为层状，而聚乙烯醇-淀粉交联液与沸石粉混合成膜为絮状、且有很多细小的孔洞，这可以解释不同包膜材料包被肥料后其养分缓释效果不同的原因。包膜前后的尿素改性聚乙烯醇-淀粉交联液与硅藻土共混材料的红外光谱分析结果表明，包膜后膜与尿素颗粒间形成了新的化学键，两者结合力强，这有助于提高包膜尿素的缓释性能。5．包膜尿素与未包膜的普通尿素相比，抑制氮素挥发效果显著，且聚乙烯醇-淀粉交联液与硅藻土混合液包膜优于聚乙烯醇-淀粉交联液与沸石粉混合液包膜材料；该类包膜材料在自然环境中能够降解。辣椒肥效试验表明，与常规尿素相比，包膜尿素具有明显提高辣椒产量、降低果实中NO₃^--N含量和提高肥料利用率的效果。总之，将改性聚乙烯醇-淀粉交联液与硅藻土（或沸石粉）按一定比例混合制成有机无机复合材料，用于颗粒肥料包膜，具有不污染土壤与环境、低成本、养分释放稳定等优点；与沸石粉相比，在聚乙烯醇-淀粉交联液中混入硅藻土效果更佳，值得推介。更多还原

【Abstract】 The production and use of environmental-friendly of coated and slow-release fertilizerwas one of the main trends for the development of chemical fertilizer industry at present, andwas necessary need for the development of modem agriculture and sustainable developmentstratagem. With the view to the exploitation of coated and slow-release fertilizer of highefficiency, environmental protection and low cost, environmental-friendly, price-lowpolyvinyl alcohol-starch combination liquid and source-broad diatomite （or zeolite powder）complex were selected as coated materials for granular fertilizer in this article. Drum technicswas used to produce coated and slow-release fertilizer. The fertilization effect of keep andcontrol of organic-inorganic complex coated and slow-release fertilizer, nutrientcontrol-release mechanism were studied systematically, the contents involved the choice ofwater resistance of membrane materials and the agreeable dosage of organic high molecularcomposite, nutrient control-releasing mechanism of fertilizers after coating,environmental-friendly and application effect in field etc. The main results were as follows:1. Formaldehyde, borax and urea could increase water resistance of polyvinyl alcohol-starch combination liquid. The lowest water absorption rate of membrane was modified byurea, and it was more fit as modifier to increase the water resistance of polyvinyl alcohol-starch combination liquid.2. The results of soil column leaching experiment indicated, when the proportion ofmembrane material and the amount of fertilizers was given, the nutrient slow-release effect ofcoated fertilizer which mixed and made by polyvinyl alcohol-starch combination liquidmodified by urea and diatomite （or zeolite powder） was the best, the proper proportion of twomaterials was found in this article.3. Nitrogen leaching process of coated and slow-release urea could described byfirst-order reaction kinetics equation （N,=N₀[1-exp（-kt）]）.The leaching constant kincreased with temperatures increment, soil water contents increase and the increasing ofwater vapor pressures. The differences of inside and outside water vapor pressures were thedirect reason for the nutrient leaching. And temperatures, soil water content etc. could affectthe nutrient leaching rate by changed the differences of inside and outside water vaporpressures. 4. Scanning electron microscope test indicated, the structure of film forming of granularfertilizer surface was different with the membrane materials. Film forming mixed bypolyvinyl alcohol-starch combination liquid and diatomite was sheet while the polyvinylalcohol-starch combination liquid and zeolite powder was flocculent and had many smallholes, it was the reason for the difference of the nutrient slow-release effect caused bydifferent membrane materials. Compared with the infrared spectrogram of before and afterurea grains coated by the mixed material of polyvinyl alcohol-starch combination liquidmodified by urea and diatomite, new chemical bond was formed between membrane andgranular urea and the binding power was strong, which helped to enhance the slow-releasecapability of urea.5. The coated and slow-release urea could inhibit volatilization of nitrogen, comparedwith the control treatment. The effect of nitrogen inhibition was better in the treatment ofpolyvinyl alcohol-starch combination liquid and diatomite than polyvinyl alcohol-starchcombination liquid and zeolite powder. The membrane of coated material could bedecomposed naturally. Capsicum fertilizer efficiency experiment indicated coated urea couldincrease capsicum yields, content of NO₃^--N decreased and increase the utilization rate offertilizer compared with the routine urea.In conclusion, the combinated material of modified polyvinyl alcohol liquid anddiatomite（or zeolite powder） could be used as coated membrane material of fertilizers with agiven proportion. The fertilizer with the above coated membrane showed advantages of lowcost, stable nutrient leaching and non-pollution to soil. Diatomite was an advisable andrecommendable coated membrane material compared with zeolite powder.更多还原