【作者】 包丽华；

【导师】 张民；

【作者基本信息】 山东农业大学 ， 植物营养学， 2010， 博士

【摘要】 控释肥料可以显著提高肥料的利用率、减少养分的挥发和淋溶损失、减轻施肥对环境的污染、改善作物的生长发育状况、提高作物的产量和品质,因而受到了人们的广泛关注。生产和施用控释肥料已经成为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。控释肥料施用后,其表面的高分子膜会残留在土壤中。随着包膜控释肥料的发展和应用范围的扩大,对高分子膜壳的降解动态以及控释肥残膜对土壤环境(植物、动物、微生物)的生物学效应进行研究,可以为高分子树脂包膜控释肥的应用和推广提供理论依据。本研究采用傅里叶变换红外光谱(FTIR)、示差扫描量热(DSC)、粘度法和气相色谱-质谱联用(GC-MS)等方法,研究了控释肥高分子残膜的降解性能、产物结构及降解机理。采用油菜、玉米的盆栽试验,以及与化学分析相结合的方法,系统研究了控释肥残膜对土壤环境和油菜、玉米的生物学效应的影响。同时,采用蚯蚓试验,从生物化学方面评价了控释肥残膜对蚯蚓的生物学效应的影响。主要研究结果如下:1.控释肥高分子残膜具有光降解性。控释肥高分子残膜在紫外光照射下,发生光氧化分解,促进PE碳链氧化断裂,逐渐生成有机类羧酸。随着残膜的光降解程度增大,羰基指数和残膜中聚乙烯的结晶度升高,而熔点和相对分子质量下降。其光降解产物中含有低分子量的烷烃、酮、醛、酯、一元羧酸和二元羧酸等。在紫外光照射条件下,含淀粉控释肥聚乙烯残膜较不含淀粉控释肥聚乙烯残膜更易降解。因此,淀粉作为添加剂明显地提高了控释肥高分子残膜的降解速率。2.控释肥高分子残膜在自然曝露光照射下,随着光照时间的增加,红外光谱表现的结果是羰基峰的强度增加。主要原因是,淀粉存在的条件下,光照后产生自由基,这些自由基作用于聚乙烯的主链上,使长链发生断裂,产生新的更多的自由基,聚乙烯链进一步发生光降解。在此反应的同时,空气中的氧气能够进入到共混物的空隙中,氧气和聚乙烯链段发生反应,产生过氧化自由基,这些过氧化自由基发生光裂解后生成羰基、乙烯基等基团。经研究发现,淀粉含量越高,对聚乙烯的促降解作用越大,因此可以说明淀粉的存在一方面也是导致混合物空隙增大,氧气更容易进入混合物当中,从而产生过氧化自由基相应的增加,因此随着光照时间的增加,红外光谱表现的结果是羰基峰的强度增加。3.不同控释肥残膜用量处理的盆栽油菜试验表明,施加控释肥残膜可以降低土壤的容重,增加土壤的孔隙度,改善通气状况,能使土壤疏松,增加土壤的通气透水性。在一定范围内,随着控释肥残膜施入量的增加,植株的生长势、叶片数、株高、叶绿素以及植株的鲜重都相应增加。施加控释肥残膜后,对植株的全氮、全磷含量没有显著影响;植株全钾含量有所增加。控释肥残膜的施入对油菜土壤的过氧化氢酶、脲酶、蔗糖酶、磷酸酶活性没有显著影响。4.不同控释肥残膜处理的盆栽玉米试验表明,在一定范围内,随着控释肥残膜施入量的增加,玉米的生长势、株高、叶绿素以及玉米的产量都相应增加。施加控释肥残膜处理的玉米的产量高于空白及只施加肥料的处理。在玉米的穗行数、行粒数没有明显增加的情况下,其千粒重有显著的增加,说明控释肥残膜处理在玉米生长的后期,即灌浆期能够提供充足的养分,以保证玉米灌浆的需要,从而提高产量。控释肥残膜的施入对玉米土壤中的过氧化氢酶、脲酶、蔗糖酶、磷酸酶活性没有显著影响。5.不同控释肥残膜处理的蚯蚓土壤试验表明,在本试验周期内,不同施用量的控释肥残膜处理后的土壤,对蚯蚓体内纤维素酶、过氧化氢酶及超氧化物歧化酶均没有显著影响。6.土壤培养条件下控释肥高分子残膜降解特性试验研究表明,控释肥高分子残膜具有降解性,在土壤培养条件下,含淀粉控释肥聚乙烯残膜较不含淀粉控释肥聚乙烯残膜更易降解。随着残膜的降解程度增大,羰基指数和残膜中聚乙烯的结晶度升高,而熔点和相对分子质量下降。7.通过对控释肥高分子残膜光照、土壤培养条件下降解产物和机理的探讨,及对土壤环境中的植物、动物、酶的生物学效应的研究,表明控释肥残膜没有对土壤环境产生显著影响。更多还原

【Abstract】 The efficiency of fertilizer have been improved evidently, loss and volatilization of nutrition elements have been reduced, waste of resources have been lightened, product quality and crop output have been enhanced markedly by applied controlled-release fertilizers, so many experts think highly of them. The production and use of controlled-release fertilizers are one of the main trends for the development of chemical fertilizers at present, and are necessary need for the development of modern agriculture and sustainable development strategies. Controlled-release fertilizers application , polymer coating residual of controlled release fertilizer will be left in the soil .With the development and application of controlled-release fertilizers, polymer coating residual of the degradation studies and biological effects in the soil environment (plants, animals, microorganisms) should be regarded. The objective of this study was to offer advice and theory proof for controlled-release fertilizers research and using.Degradabilities, product and degradation mechanism of polymer coating residual of controlled release fertilizer were investigated by using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), viscosimetry and gas chromatography-mass spectroscopy (GC-MS). Cole and maize potted experiment and together with method of chemical analysis have been used in the paper. The purpose of this paper was to study effects of polymer coating residual of controlled release fertilizer on soil physical, chemical and biological property and biological effects on cole and maize. Meanwhile, the use of earthworm test, evaluated on the biological effects of polymer coating residual of controlled release fertilizer of earthworms from the biochemical aspects. The main results were summarized as follows:1. Controlled release fertilizer coating residual was photodegradable. Controlled release fertilizer coating residual under UV irradiation, photo-oxidative decomposition, promote oxidation of the carbon chain fracture PE gradually generate organic acids. With increasing the degree of degradation, the carbonyl index and crystallinity of polyethylene in Coating increased, but the melting point and relative molecular weight of polyethylene in Coating decreased. Some low molecular weight products, such as alkyl hydrocarbon, ketone, aldehyde, ester, carboxylic acid and binary carboxylic acid were detected in the degraded Coating. The coating residual containing starch was degraded much more rapid than non-starch coating residual under UV irradiation. Therefore, the starch as an additive can significantly improve the degradation rate of controlled release fertilizer coating residual.2. Controlled release fertilizer coating residual in the natural exposure illumination, with the increase of irradiation time, the results of infrared spectra showed the carbonyl peak intensity increased. The main reason was the existence free radicals after exposure under of starch .The role of these free radicals in the polyethylene main chain to long chain was broken, and the occurrence of new and more free radical further light polyethylene chain degradation. In this reaction, while oxygen in the air can enter into the gap in the blends, oxygen and reaction of polyethylene chains to produce free radicals, these free radicals generated after photo-decomposition of carbonyl, vinyl, etc. group. The study found that the higher starch content, the degradation of polyethylene in promoting the greater, it illustrates the presence of starch mixture while also contributed to the gap increases, the oxygen into the mixture which is easier, resulting in a corresponding increase in free radicals.Therefore, with the illumination time increases, the performance results of IR carbonyl peak intensity was increased.3. The results of potted cole experiment showed that controlled release fertilizer coating residual could reduce soil bulk density, increased soil total porosity. So aerated status of soil has been improved and loose soil increased the aerated and dank character of soil. The contents of chlorophyll , height of cole, number of leaves, fresh mass and growth potential of the cole had been increased by controlled release fertilizers coating residual. The result that the total N and total P of the cole were not changed obviously indicated that the absorption of N and P had not produced adverse effects. The total K of the cole had been increased by controlled release fertilizers residual coating. Controlled release fertilizer coating residual applied to the soil on catalase, urease, invertase, phosphatase activity was not significantly affected.4. The results of potted maize experiment showed that within a certain range, controlled release fertilizers coating residual was applied to increase the amount of corn growth potential, plant height, chlorophyll and yield of maize have increased. Controlled release fertilizers coating residual was better than the yield of corn processing blank and only the fertilizer treatment. Number of rows in the corn ear, kernels per row no apparent increase in cases, the grain weight had increased significantly, indicating controlled release fertilizers coating residual late in the growth of maize, namely, filling to provide sufficient nutrients to ensure corn filling the need to increase production. Controlled release fertilizers coating residual applied to the soil of the maize catalase, urease, invertase, phosphatase activity was not significantly affected.5. Controlled release fertilizers coating residual earthworm soil tests showed that in the period of this experiment, different amounts of controlled release fertilizers coating residual treated soil, the earthworm enzyme, catalase and superoxide dismutase were no significant impact.6. The degradation experiment of thermoplastic coating residual of controlled release fertilizer under soil incubation environment indicated that controlled release fertilizer coating residual was degradable. The coating residual containing starch was degraded much more rapid than non-starch polyethylene coating under soil incubation environment. With increasing the degree of degradation, the carbonyl index and crystallinity of polyethylene in coating residual increased, but the melting point and relative molecular weight of polyethylene in coating decreased.7. The degradation experiment of thermoplastic coating residual of controlled release fertilizer under irradiation and soil incubation environment indicated that degradation mechanism of controlled release fertilizers coating residual was free radicals mechanism. Potted plants experiment showed that biological effects on soil environment such as plant, animal and soil enzyme was safe. Overall, controlled release fertilizers residual coating was no significant impact on soil environment.更多还原