江苏沿海滩涂围垦区土壤特征与新围垦滩涂农地开发利用对策

发布时间：2018-03-01 07:12

本文关键词： 滩涂围垦区土壤特征农地开发利用对策江苏沿海　出处：《南京大学》2015年硕士论文　论文类型：学位论文

【摘要】：滩涂是一种重要的后备土地资源,在当前我国耕地资源紧缺、耕地质量整体偏低的背景下,具有较大的土地资源开发潜力。滩涂的利用主要是围垦,随着滩涂围垦不断向海推进,起围高程越来越低,围垦速度快、规模大,围垦的滩涂土地利用是个难题。滩涂围垦后多以农业利用为主,而滩涂土壤含盐量高,肥力低,限制了农业利用效率;开展滩涂围垦区土壤性质和演化趋势的研究,有利于促进农作物种植条件的提高,可为滩涂围垦区土壤改良、农业生产等提供科学合理的依据。本文以大丰沿海滩涂及围垦区为典型研究区,分析了不同年限围垦区采集的土壤剖面的上壤机械组成,pH值,水溶性总盐分含量,土壤有机质,全氮、全磷、全钾等土壤物理、化学、养分性质的差异与变化特征;在分析归纳江苏沿海滩涂利用存在的问题,总结滩涂开发主要利用技术的基础上,提出了新围垦滩涂农地开发利用对策。研究结果如下:(1)不同围垦年限土壤剖面机械组成粉砂含量较多、砂粒和粘粒含量较少。滩涂围垦之后,粒度组成有明显变化。主要表现为砂粒含量不断降低,粉砂含量量逐步增多,粘粒含量变化相对较小。粉砂含量的分布体现出较好的由海向陆演变的趋势。滩涂围垦区土壤剖面质地大多为粉砂质壤土,土壤粉砂含量大多高于70%,粘粒含量一般不超过20%,在土壤发育过程中,土壤剖面的一般机械组成变化趋于稳定,上壤结构随着土壤发育程度而变化。(2)土壤pH值分布在7.92～9.51之间,呈碱性到强碱性;土壤pH值随着成陆时间的增加略有下降,在剖面的分异程度亦有所增加。从围垦初期的9.51降低至围垦43年后的7.92。含盐量在0.15-15.88 g/kg之间变化,平均含盐量为3.09 g/kg,为典型滨海盐渍化土。土壤剖面平均含盐量 FH5(9.92 g/kg)F1(4.56 g/kg)FH1(0.82 g/kg)DL1(0.39 g/kg),各采样区域土壤含盐量差异明显。(3)不同年限垦区十壤养分含量存在较大差异。有机质含量分布在1.83～13.40 g/kg之间,围垦年代越早的垦区有机质含量越高。经过多年耕作之后,受耕翻、挖沟、植物等因素的影响,土壤盐分含量降低,物理性状改善,微生物数量增加,促进了有机质的转化与积累。在土壤剖面中,表层土壤有机质含量较高,深层土壤有机质含量较低,围垦年限较长的土壤剖面上有向下骤减的垂直分布特征,但各层次间含量差异并不显著。不同围垦年代全氮平均值为0.40 g/kg,变化范围在0.08～0.89 g/kg,全氮含量的相对分布特征与土壤有机质含量的分布趋势相一致;全磷变化范围在0.55～0.94 g/kg,为缺乏和很缺乏等级,平均值为0.64 g/kg。全钾含量变化范围为20.5～26.1g/kg,均为第三等级(中等),且变化差异不大;整个研究区全钾平均含量为22.1 g/kg。(4)在综合分析滩涂围垦区土壤特性的基础上,分析归纳江苏沿海滩涂利用存在的问题,探讨了新围垦滩涂农地的开发利用的对策;主要包括:空间规划技术、土地整理技术、盐碱地改良技术和农地生态管护技术等四个方面。
[Abstract]:Beach is an important reserve land resources, the cultivated land resources shortage in China, the overall quality of cultivated land is low in the background, with great potential land resources. The beach is mainly by reclamation, reclamation with constantly advancing to the sea, from the surrounding elevation is more and more low speed, large scale, reclamation, reclamation the land use is a problem. After the reclamation in agricultural utilization, and soil salinity is high, low fertility, limited agricultural utilization efficiency; research of tideland reclamation soil properties and evolution trend, is conducive to the promotion of crop planting conditions improved for soil improvement of tideland reclamation, provide a scientific and reasonable basis for agricultural production. The coastal reclamation area of Dafeng and as a typical study area, analyzed the soil mechanical composition, soil profiles were collected in different years of reclamation area of pH, total water soluble The salt content, soil organic matter, total nitrogen, total phosphorus, total potassium, soil physical, chemical, and variation of nutrient properties in coastal Jiangsu; analyze the existing problems, summarizes the main beach development using the technology on the basis of the proposed new reclaimed farmland mudflat development and utilization countermeasures. The research results are as follows: (1) Different Reclamation Years soil mechanical composition more silt content, less sand and clay content. After reclamation, grain composition has changed significantly. Mainly for the sand content decreased, silt content gradually increased, clay content is relatively small change. Distribution of silt content reflects better evolution from the sea the land reclamation area of tidal trend. Soil profile texture is mostly silty loam, sand content of the soil powder is more than 70%. The clay content is generally not more than 20%, in the process of soil development, soil profile The general mechanical composition change tends to be stable, the soil structure varies with the degree of soil development. (2) the pH value of soil distribution in 7.92 ~ 9.51, alkaline to alkaline soil; pH value increased with the increase of the land into time decreased slightly, also increased in differentiation profile. 7.92. salinity from 9.51 at the early stage of reclamation reclamation reduced to 43 years after the change in 0.15-15.88 between g/kg, the average salt content was 3.09 g/kg, as a typical coastal saline soil. The soil profile average salt content of FH5 (9.92 g/kg) F1 (g/kg 4.56) FH1 (0.82 g/kg) DL1 (0.39 g/kg), the sampling area of soil water the salt was different. (3) there is a big difference between the different years of reclamation area ten soil nutrient content. The content of organic matter distribution between 1.83 ~ 13.40 g/kg, the content of organic matter in the reclamation reclamation area earlier higher. After years of cultivation, by ploughing, trenching, and other factors affecting plant, soil salinity Decreasing the content of physical properties improved, microorganisms increase and promote the transformation and accumulation of organic matter in soil profile, soil organic matter content is high, the deep soil with low organic content, soil reclamation longer has plummeted down the vertical distribution characteristics, but not significant difference between different levels of content different reclamation year average total nitrogen was 0.40 g/kg, the change in the range of 0.08 ~ 0.89 g/kg, the relative distribution trend and the distribution characteristics of soil organic matter content is consistent with the content of total nitrogen; total phosphorus ranged from 0.55 to 0.94 g/kg, and for the lack of a lack of level, the average range of 0.64 g/kg. for potassium content 20.5 ~ 26.1g/kg, were third grade (medium), and had no difference; the average content of the whole study area of total potassium was 22.1 g/kg. (4) based on comprehensive analysis of soil properties in the Coastal Reclamation District, analysis The problems existing in the utilization of Jiangsu coastal tidal flat are discussed, and the Countermeasures for the development and utilization of the new reclamation farmland are discussed, including four aspects: spatial planning technology, land consolidation technology, saline alkali soil improvement technology and farmland ecological management and protection technology.

【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P748

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