滨海盐碱地棉花秸秆培肥技术及其改良效果

	滨海盐碱地棉花秸秆培肥技术及其改良效果
	孙凯宁
学位类型	博士
导师	于君宝
	2013-05-28
学位授予单位	中国科学院研究生院
学位授予地点	北京
学位专业	环境科学
关键词	滨海盐碱地堆腐棉秆还田缓释肥改良效果
摘要	黄河三角洲有广泛的滨海盐碱地分布，因其盐分高、肥力低、结构差等障碍因素，导致土地利用率偏低。前人通过工程设施、化学方法和生物修复等技术手段对盐碱地进行改良，秸秆还田模式便是其中之一。棉花是黄河三角洲地区的主要经济作物，棉花秸秆数量巨大，并大量剩余。关于秸秆还田有较多报道，但利用棉秆对滨海盐土进行改良的研究却较为鲜见。本文在结合前人研究和当地现状的基础上，通过棉秆腐熟度评价、棉秆腐熟物类肥料研制及肥效试验、棉秆还田试验和有机肥‐无机肥配施试验等研究方法，探索了棉秆利用和改良滨海盐土的可行性途径。主要研究结果如下：（1）棉花秸秆腐熟需要适宜的C/N 和微生物菌剂添加。综合各堆腐指标（高温持续时间、EC、pH、C/N、T 值和GI）的动态变化可知，棉秆-氮肥-菌剂处理在C/N 为25/1 的条件下，相比其它处理可以更快腐熟；单纯调节C/N 处理和单纯添加菌剂处理均未能腐熟。同时，建立了棉花秸秆腐熟度评价体系：TOC、TN、C/N、T 值可作为棉秆腐熟度评价的优选指标，pH 值、温度和GI 为一般性评价指标，而EC 不适合作为评价指标。（2）研制了兼备有机肥、无机肥和缓释肥性能的棉秆腐熟物类肥料-双包膜球形肥（DSCF）。该肥料由外膜、内膜和肥芯三部分组成。秸秆腐熟物是外膜的主要组成部分，无机矿物-腐植酸构成了内膜，复合肥为肥芯。外膜具有吸水保水性能；内膜的屏障作用使肥芯中无机养分释放速率降低。经扫描电镜观察发现，该肥料外表面布满大量的细小褶皱缝隙。经室内模拟试验可知，双包膜球形肥可以提高土壤最大田间持水量和减少土壤水分蒸发量；在35 天内，该肥料的总养分释放量低于70%。与此同时，试制了棉秆类有机无机复混型肥料（大、小两类）。（3）棉花秸秆还田可以有效增加土壤孔隙度，降低土壤容重；土壤孔隙度、容重与棉秆还田量分别呈正相关和负相关的关系；等还田量条件下，不同粒径棉秆处理增加土壤孔隙度的大小顺序为：5cm 粒径棉秆 >3cm 粒径棉秆 >1cm 粒径棉秆。20t/ha 还田量明显增加了0~20cm 土层粘、粉粒的比例。5cm 粒径棉秆在10t/ha 还田量条件下可以明显降低土壤pH 值。0~20cm 土层中的主要可溶性盐离子受棉秆还田影响明显，表现为：各还田处理均可降低该土层中的Na+、Cl-、SO42-含量，而15t/ha 和20t/ha 还田量均增加了该层K+、Ca2+、Mg2+的含量；0~20cm土层中的可溶性盐总量随棉秆还田量的增加而递减，降盐幅度为：20t/ha 还田量 >15t/ha 还田量 >10t/ha 还田量。中高棉秆还田量（15t/ha 和20t/ha）对增加棉花茎粗、棉桃数、株高、叶面积、叶绿素含量和果枝数有一定的效果。（4）选取了5 种肥料类型：市售普通复合肥、市售普通复混肥、自制有机无机复混型肥（大、小两种）和双包膜球形肥。田间试验表明，等N、P、K 施入条件下，双包膜球形肥和小颗粒自制复混肥表现出较好的效果，二者较市售复混肥的氮肥表观利用率分别提高了7.9 和4.2 个百分点；磷肥表观利用率分别提高了2.2 和1.6 个百分点；钾肥表观利用率分别提高了3.3 和0.5 个百分点；其中该两种自制肥的磷肥表观利用率与市售复混肥差异极显著（P <0.01），双包膜球形肥的氮肥表观利用率与市售复混肥差异显著（P <0.05）。增加了棉株营养器官和生殖器官中N、P、K 的积累量；与市售复混肥相比，分别增加籽棉产量11.98%和7.39%；分别增加皮棉产量11.83%和7.29%。（5）等无机肥施入量条件下，有机肥处理（牛粪单施、牛粪-棉秆混施）可以增加棉花的单铃重和果枝数，表现为混施处理优于单施处理；棉花主要生长期（除苗期）混施处理的株高均高于对照。单铃重和桃数随混施处理施入量的增加而增加；有机肥处理对棉花的茎粗和衣分无显著影响；高量单施处理（牛粪15t·ha-1）和所有混施处理的籽棉和皮棉产量均比CK 有所增加。有机肥的施入改善了土壤物理结构，土壤孔隙度随有机肥施入量的增加而升高；在吐絮期时大部分有机肥处理0~30cm 土层的pH 明显降低。0~10cm 土层有机质含量随牛粪添加量的增加而增加；而在等牛粪添加量条件下，混施处理高于单施处理。0~10cm 土层可溶性盐离子的含量高于10~20cm 和20~30cm 土层；0~10cm 和10~20cm 土层中Na+、Cl-、SO42-、K+、Ca2+、Mg2+在棉花的四个主要生长期总体呈“升-降-升”的趋势。混施处理对棉花苗期和蕾期的各土层起到了较好的脱盐效果，且随有机肥施入量的增加，脱盐越明显；吐絮期时，中高量混施处理明显降低了0~30cm 土层的可溶性盐总量；花铃期时，各有机肥处理的降盐效果不明显。
其他摘要	A vast area of the coastal saline-alkali soil exists in the Yellow River Delta.Because of its high salinity, low fertility and poor structure, the utilization of land islow. There are many previous researches on saline- alkali soil improvement, such as using engineering facilities, chemical and biological restoration techniques, and straw returned to soil is one of the important techniques. Cotton is the main economic crops of the Yellow River Delta, which lead to a huge number of cotton straws after harvest. A large number of studies about straw returned to soil have been reported, while few about cotton straw returned to saline-alkali soil. Combined with the previous studies and the local status, 5 experiments (cotton straw maturity evaluation, the manufacture of the cotton straw composts type fertilizer and effect test, the test of cotton straw returned to soil, the mixed application of chemical fertilizers with manure) were set to explore the new ways to utilize the cotton straw and improvet the coastal saline soil. The main results are as follows: (1) It was important to provide an appropriate C/N and add microbial agents for the promotion of cotton straw decomposition. After comprehensive consideration on the dynamic changes of the duration of high temperature, EC, pH, C/N, the T value and GI, the composting speed of the cotton stalk - nitrogen - microbial agents treatment, processing in the C/N 25/1, was faster than the others. The adjusting C/N only treatment and adding agents only treatment were failed to mature. According to the cotton stalks maturity evaluation system: TOC, TN, C/N, T value were the preferred indicators, pH, temperature and GI were the general evaluation, and the EC was not suitable as an evaluation index. (2) The double-coated slow-release organic-inorganic compound fertilizer (DSCF) was manufactured. The DSCF was three-layer structure, of which the outer coat mainly constituted with cotton straw compost had the properties of water absorption and water-retention, the inner coat for nutrient slow-release and improvement of fertilizer was mainly constituted with HAs and inorganic minerals, and the core for nutrients supply was water-soluble NPK compound fertilizer. A large number of small folds gap were found at the outer surface of DSCF by the scanning electron microscope. The indoor simulation experiments showed that the DSCF could improve the largest water-holding ratio and reduce the water lose from evaporation. Within 35 days, the total nutrient release ratio was less than 70%. Meanwhile, the organic-inorganic compound fertilizers of cotton type (large and small models) were developed. (3) Cotton straw back to soil could increase soil porosity and reduce soil bulk density. The soil porosity increased as the amount of cotton straw increased, while the bulk density was on the contrary. The order of the amount of increasing the soil porosity by different cotton straw particle size was: 5cm > 3cm > 1cm. The 20t/ha treatment could increase the proportion of clay and silt in 0~ 20cm soil layer. The 5cm particle size cotton straw could significantly reduce the soil pH at 10t/ha cotton straw back to soil amount.0~ 20cm soil soluble salt ions effected by cotton stalk to soil were shown as follows: each cotton straw treatment could reduce the Na+, Cl-, SO42- content, while the treatments of 15t/ha and 20t/ha straw amount could increase the K+, Ca2+, Mg2+ content. The total soluble salts showed a decreasing trend with the increase of the cotton straw amount at 0~ 20 cm soil layer. The 15t/ha and the 20t/ha cotton straws treatment could increase the cotton stem diameter, number of bolls, plant height, leaf area, chlorophyll content of leaves and the number of fruiting branches. (4) Five fertilizer types, which were ordinary compound fertilizer, ordinary organic-inorganic mixed fertilizer, homemade organic-inorganic mixed fertilizer (large and small) and DSCF, were selected to test. DSCF and small particles homemade fertilizer showed better results. Compared with ordinary organic-inorganic mixed fertilizer, the two increased N, P, K apparent efficiency by 7.9 and 4.2, 2.2 and 1.6, 3.3 and 0.5 percentage points, respectively, and also increased N, P, K accumulation of cotton vegetative organs and genitals, the seed cotton yield an increase of 11.98%, 7.39%, respectively; the lint yield an increase of 11.83% and 7.29% respectively. (5) The organic fertilizer treatment (single application of cow dung and cow dung- cotton straws mixed fertilizer) could increase the cotton boll weight and the number of fruit branches at the same organic fertilizer nutrient conditions. It showed that the mixed treatments were better than the single treatments; the mixed treatments were higher than that of the CK in the main cotton growth periods (except for the seedling stage). The cotton boll weight and peach number increased with the amount of mixed fertilizer increased. There was no significant effect on cotton stem diameter and lint percentage by the treatments, while seed cotton and lint could be increased by the high amount single treatment and all the mixed fertilizer treatments. The soil porosity increased with the amount of organic fertilizer application increased. The soil pH (0~30cm soil layer) of most organic fertilizer treatments significantly reduced at the boll opening stage. Soil organic matter in 0~ 10 cm soil layer increased with the increasing of the addition of cow dung, and mixed treatments showed higher that the single treatments at the same level of cow dung amount. The soluble salt content in 0-10cm soil layer was higher than that of 10~ 20cm and 20~ 30cm. The main salt ions (HCO3-) showed ‘up - down - up’ trend through the main cotton growth periods at 0~ 10cm and 10~ 20cm soil layer. Mixed treatments indicted a better desalination and desalination effect, which was more obvious with the increase of organic fertilizer application amount applied at the cotton seedling and bud stage. The middle and high amount of mixed treatments could significantly reduce the total soluble salts of 0~ 30cm soil layer at the boll opening stage, while the organic fertilizer treatments were not obvious at the blooming stage.
语种	中文
文献类型	学位论文
条目标识符	http://ir.yic.ac.cn/handle/133337/6727
专题	中国科学院烟台海岸带研究所知识产出_学位论文
推荐引用方式 GB/T 7714	孙凯宁. 滨海盐碱地棉花秸秆培肥技术及其改良效果[D]. 北京. 中国科学院研究生院,2013.

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