【作者】 陈剑秋；

【导师】 张民；

【作者基本信息】 山东农业大学 ， 植物营养学， 2012， 博士

【摘要】 本研究针对目前我国肥料以低品位氮肥为主的产品结构和肥料利用率严重低下等应用现状，通过对植物油、腐植酸等易降解膜材的筛选、复配、改性和配套工艺研究试验，以及低温、不同土壤含水量、田间条件下缓控释肥的养分释放试验，研究了膜材料成膜特性、微观结构和养分释放特性之间的关系，研究了缓控释肥在不同气候和土壤含水量条件下的养分释放特征，并对缓控释肥料在水稻上的施用技术进行了探讨，主要研究结果如下：1．植物油包膜尿素的释放期与其养分释放特征曲线存在一定的关系，较短的释放期对应“抛物线”状养分释放特征曲线，较长的释放期对应“S”型释放特征曲线，释放期处于二者之间的植物油包膜尿素对应“斜线”状养分释放特征曲线。供试植物油包膜复合肥养分释放特征类似幂乘函数曲线，氮、磷、钾的累积释放曲线趋势大致相同，但是氮素的释放速率最快，钾素的释放速率次之，磷素的最慢。供试植物油包膜尿素和复合肥的养分释放动力学特征可以用线性回归方程和多项式方程描述。植物油热交联固化反应成膜特征表明，随反应温度的升高，植物油A、B组分固化反应速度逐渐加快。在所有处理中T6固化效果最好，但在缓控释肥喷涂包膜工艺过程中，T3处理的包膜效果可能会优于T6。SEM微观结构分析表明，植物油尿素包膜的内表面整体比较平整，而植物油复合肥包膜的内表面有非常多的珊瑚状凸起，且杂乱无序，表明复合肥颗粒外表面与植物油膜层结合的更加紧密。植物油尿素包膜外表面比较光滑，有少量圆滑的凸起和小微孔，断面切口光滑平整，光泽润滑。植物油组分热交联固化后，在肥料颗粒表面形成无明显边界的数层乃至数十层重叠的薄膜，该膜层不是均一体系，是其包膜外表面不平整的重要原因。2．腐植酸包膜缓控释肥制作工艺研究表明，在本研究的生产温度范围内，70℃和80℃条件下制作的产品养分控释性能好，风化煤的粒度也是影响其释放率的关键因素，风化煤粒度越粗，肥料养分释放的就越快；B/H值越大，肥料养分释放速度越小，粘结剂对腐植酸缓控释肥养分释放控制的贡献率大于风化煤。供试腐植酸包膜缓控释肥采用线性回归方程和2级多项式方程能够较好的表达其养分释放的动力学特征。SEM微观结构分析表明，腐植酸膜层断面呈现明显的分层结构，两层较厚的腐植酸组分形成的粗糙层和两层薄薄的粘结剂组分形成的光滑致密层间隔分布，内表面布满大量的空隙，这与腐植酸颗粒状组分直接相关，外表面呈层叠状分布，其上散布着许多微孔和颗粒状物质。3．缓释粘结剂制作研究表明，U/F影响缓释粘结剂的产率和活性系数（AI），U/F值是1.2时产率最高，而U/F值为1.4时缓释粘结剂的活性（AI）最高。脲醛缓释复混肥以脲甲醛为骨架，不使用粘土，可有效防止肥料颗粒吸水膨胀快速崩解的现象，通过研究制备脲醛缓释粘结剂，结合复混肥生产工艺获得脲醛复混肥这种新型缓释肥料，设备投资少，生产成本大大降低，产品性能好，有利于其在农业生产上快速推广应用。4．改性硫包膜尿素研究表明，SCU、PSCU和MSCU的释放曲线皆类似顺时针旋转90度的“L”型，养分释放速率SCU＞PSCU＞MSCU，应用幂乘方程描述供试改性硫包膜尿素拟合度较高，可以方便快捷的预测改性硫包膜尿素不同时期的养分累积释放率。硫膜改性增韧研究表明，抗冲击、碰撞和摩擦效果最好的是MSCU处理，碎屑量仅是PSCU的0.46倍，SCU的0.07倍，差异显著（P＜0.05），因此采用在硫磺包膜尿素外层包裹树脂改善硫膜脆性的方法切实可靠。SEM微观结构分析表明，硫磺膜层断面（x300）结构排列的整齐紧密，（x2000）显示硫磺膜断面分为三个层次，中间层结构相对疏松，上下两层结构紧实致密；内表面未见明显孔隙，可以发现有大量密集的褶皱；外表面无可见孔隙，发现有大量由硫磺粉粒形成的球状小颗粒镶嵌在膜的外表面。由硫加树脂和改性硫加树脂膜层断面照片，可发现其膜层皆由细腻的树脂和粗硬的硫磺两层构成，区别在于改性树脂膜层与硫磺层结合的不如硫加树脂包膜紧密，外表面后者比前者更光滑平整，表明后者树脂组分延展性和愈合性更好，更有利于封闭硫膜缝隙和提高膜层韧性。5．研究表明，杨越超等人提出的100℃沸水中浸提进行缓控释肥快速检测的方法简便可行，适用于采用相同生产工艺生产的不同批次的缓控释肥快速评价其养分释放期，但在膜材料、添加剂和控制参数如喷涂时间、喷头雾化效果和包膜肥料核芯等发生变化时，既定快速预测回归方程可靠性较差。浸提温度越低，供试控释尿素的养分释放期也越长，CRF1和CRF2在15℃的释放期分别是25℃的1.5倍和1.67倍，5℃的释放期皆为25℃的2倍，温度降低对供试控释尿素释放期的影响效应逐渐减弱。春季田间累积养分释放曲线近似“J”字型，夏季呈“斜线”状。土壤含水量对供试控释肥养分释放率的影响试验表明，50%土壤相对含水量是不影响土壤中供试控释尿素养分释放速率的临界含水量。6．控释肥水稻试验表明，施肥量：在氮肥全量50%水平上增施氮肥，增产效果显著，在氮肥全量70%水平上增施氮肥效果不显著，所有控释尿素等养分施肥处理中，增产效果CRU70%＞CRU100%＞CRU50%，综合控释尿素不同处理对水稻产量和氮素利用率的影响，控释尿素施用全量的70%处理效果最佳。控释尿素与普通尿素配比：供试水稻产量CRU70%＋PU30%＞CRU50%＋PU50%＞CRU42%＋PU28%＞PU100%＞CRU70%＞CK，因此70%控释尿素搭配30%普通尿素作为氮源施用效果最好。控释尿素类型：供试水稻产量和氮肥利用率都遵循同样的规律PSCU＞SCU＞PCU＞PU＞CK，因此施用PSCU控释尿素效果最好，这可能与该类型控释尿素为改性树脂和硫磺双层包膜有关，不但实现了氮素养分参照水稻营养需求的控制释放，而且有效补充了硫营养。更多还原

【Abstract】 Experiments of screening, compounding, and modifying easily degradable material suchas vegetable oil and weathered coal were conducted to study film-forming properties,microstructure, and nutrient release characteristics of SCRF. Experiments of nutrient releaseunder different conditions and efficiency test about several crops were conducted to discussnutrient release characteristics of SCRF and fertilizer formulations on field crops. The resultswere as follows:1. There was a certain relationship between stated release time of vegetable oil coatedurea and its nutrient release curve. The nutrient release curves were parabola pattern forcoated urea with shorter release time,“S” pattern for coated urea with longer release time, andlinear pattern for other coated urea. The nutrient release characteristics of vegetable oil coatedcompound fertilizer were similar to the power multiplication function curve. The nitrogenrelease rate of coated compound fertilizer was the fast, next was potassium, and phosphorusrelease rate was the slowest. Nutrient release dynamics characteristics could be describedusing the linear regression equation and the polynomial equation. Vegetable oil thermalcrosslinking reaction showed that curing reaction of vegetable oil speeded up with thereaction temperature. The effect of T6was the best of all the treatments. The effect of T3maybe better than that of T6in the process which fertilizers were coated. Microstructure analysisshowed that the inner surface of the vegetable oil coated urea was a whole formation, but theinner surface of the film had a lot of coral shaped bulges. The external surface of the film wassmooth. There were a small amount of smooth bulge and micropore. The fracture of the filmwas smooth and sleek. The film was without distinct boundaries and serried. The film was nota homogeneous system, so that surface of the film was irregular surfaces.2. By measuring the nutrient release characteristics of slow/controlled release fertilizers,the results showed that production made under the temperature of70℃and80℃was betterin controlling nutrient release. The bigger the particle size of weathered coal was, the worsethe performance of fertilizer was. The binder VS humic acid (B/H) ratio with biger value hadbetter effect on the nutrient release performance of fertilizers. Contribution rate of binder wasmore than that of weathered coal in controlling nutrient release. Microstructure analysisshowed that the film consisted of two layers. One was the rough layer which was constitutedby weathered coal; another was the dense layer which was constituted by a special binder. Inner surface of the film covered with a large number of gaps. External surface of the filmappeared cascade-like distribution. Many micropore and particulate matter were scatteredover external surface of the film.3. UF was slow-release nitrogen fertilizers by chemical synthesis. Through studyingurea-formaldehyde binder, urea-formaldehyde compound fertilizers were got as new slowrelease fertilizer, combined with manufacturing technique of compound fertilizer. Theinvestment was low for process equipment, and technology is very mature. Using existingfertilizer production line, the cost of production was significantly reduced in comparison withsimilar products. These advantages benefited urea-formaldehyde fertilizers to be rapidlypopularized for agricultural production.4. The release curve of SCU, PSCU, and MSCU were similar to the "L" shape whichrotated90degree. The order of nutrient release rate was SCU＞PSCU＞MSCU. The nutrientrelease characteristics of modified sulfur coated urea were similar to the power multiplicationfunction curve. The anti-collision and friction effect of MSCU was the best of all thetreatments. Debris of MSCU was0.46times more than that of PSCU, and was0.07timesmore than that of SCU. The difference among the three groups was statistic ally significant(P<0.05). It was viable that sulfur coated urea was resined to improve the brittleness of sulfurfilm. Arrange and deposit of sectional material were relatively compactness. The sulfur filmconsisted of three layers which were scatter layer and dense layer. There were a large numberof intensive wrinkle on the inner surface and small pearl-like grains on the external surface.The modified sulfur film consisted of two layers which were resin layer and sulfur layer.5. The rapid method could be used to determine nutrient release rate and stated releasetime. Therefore, different batches of slow/controlled release fertilizers could accuratelydetermine stated release time. By rapid measuring method predicted nutrient release period,only CRF13met the25%upper limit of allowable error of12samples. When conditions suchas envelope materials, additives and spraying temperature were changed, the evaluation ofslow/controlled release fertilizers was not reliable with the original prediction equation. Therapid prediction equation needed to be obtained according to making mathematical statisticsafresh.The release rate of controlled release fertilizer fluctuated with the decrease of theextraction temperature. The stated release longevity of CRF1and CRF2at15℃wererespectively1.5times and1.67times than those at25℃. The stated release longevity ofCRF1and CRF2at5℃were both2times than those at25℃. Effects of lower thetemperature on stated release time of controlled release urea had weakened. The nutrient release curve in spring was “J” pattern and a diagonal pattern in summer. The test of soilwater content on the nutrient release rate of the SCRF showed that50%was the critical valueof soil relative water content which did not affect the nutrient release rate of the SCRF in soil.6. Yield of the rice increased significantly when application of fertilizer was more than50%level of total nitrogen. The difference of rice yield was not statistic ally significant whenapplication of fertilizer was more than70%level of total nitrogen. The order ofyield-increasing effect was CRU70%＞CRU100%＞CRU50%. Yield with70%treatment wasthe highest. The order of rice yield was CRU70%＋PU30%＞CRU50%＋PU50%＞CRU42%＋PU28%＞PU100%＞CRU70%＞CK about mixture ratio between CRU and PU. ApplyingPSCU not only controlled nutrient release rate but also applied elemental sulfur by reason oftwo films, So that yield with PSCU treatment was the highest among four kinds of fertilizers.更多还原