【作者】 王玉婷；

【导师】 何明友；

【作者基本信息】 成都理工大学 ， 地球化学， 2008， 硕士

【摘要】 土壤是母岩、气候与生物共同作用下的产物,是农田生态系统养分循环的贮存库和交换库。长期以来,由于现代工业的发展和人类自身活动的增加,大量带有重金属的废水、废气、废渣、无机化肥、农药等进入地表环境,并在土壤中积累,破坏了农业生态系统,影响了农业生产的安全,带来了一系列的生态问题。地质环境是农业生态系统中重要的物质条件,是农作物赖以生存的载体。项目通过土地整理区的土壤、水、大气质量的地质地球化学调查填图,查明土壤中元素的分布和分散富集特征;了解元素相关地球化学指标的含量和分布状况和研究元素的迁移规律,从而为提高土地利用价值,农业生产配方施肥方案的制定,无公害农产品、绿色农业生产基地优选,农业种植结构调整,保证农产品安全等提供基础数据和科学依据。通过该项目的实施将为农业地质调查成果在土地整理、发展农业生产和提高居民生活质量方面的有效应用提供示范。“金土地工程”是四川省政府落实国家“三农”政策和新农村建设的具体实施工程,是对一定区域内的田、水、路、林、村宅等实施综合整治,改善土地利用结构和居民生产、生活条件,恢复生态环境,新增有效耕地,提高耕地质量,提高土地利用率和产出率的综合整治工程。“金土地工程”农业地质调查是该工程中的一项重要的基础性调查研究内容,切实为地方经济可持续发展服务的基础工作。正因为如此,本文采用多学科的现代理论和方法对宜宾市江安县桐梓镇耕地土壤特征进行了地球化学研究。内容包括:区域地质背景;土壤矿物学;土壤元素地球化学;有害元素地球化学特征;耕地质量地球化学评估等。通过上述研究,取得如下成果:①成土母岩主要为:遂宁组紫色泥质岩、粉砂质泥岩;沙溪庙组深灰、杂色长石岩屑砂岩。②紫色土组成更接近成土母岩组成。水稻土组成与紫色土组成有明显差别,水稻土中贫CaO、Na₂O,而Cd、Hg、S富集。③土壤中普遍富含重金属元素Pb、Ni、Cu、cd,并有局部富集现象。贫N、P和有机质。④土壤酸碱性为:跑沙大土、黄泥田pH值6.5～8.5,主要为酸性土壤,其次为弱酸和微碱性土壤;沙土、沙田pH值小于5.5,为酸性土壤。⑤研究区表层土壤中重金属元素Cd超过了国家土壤环境质量一级标准,为二级土壤。总体来看,由于研究区表层土壤中重金属元素Cd超过土壤环境质量一级标准,致使研究区土壤环境质量为国家二级土壤,总评上研究区土地质量为优。本论文以“金土地工程”农业地质调查子项目——宜宾市江安县桐梓镇土地整理区农业地质调查为研究区,以地质地球化学研究方法为手段,对该区的耕地土壤地球化学特征进行研究。重点对表层土壤、横向综剖面土壤以及垂向剖面土壤为主要研究对象,分析研究土壤常量元素特征、土壤微量元素特征、土壤有害元素特征以及土壤的矿物组成特征及其分布。在项目实施的一年中,对研究区进行面积性表层土壤样、横向综合剖面测量、垂向（浅井）剖面、大气降尘、水环境测量以及农作物等的采集工作,鉴于本文研究重点为耕地土壤,因此大气降尘、水环境以及农作物的测试成果在本文中没有体现。通过对所采集的土壤样测试分析,对研究区的土壤常量元素、微量元素、有害元素等其他相关元素有了比较深刻的了解,也了解到它们在土壤中分布特征和现存状况,为评价研究区土壤质量奠定了基础工作。更多还原

【Abstract】 The soil is a result of combining the actions of oxygen and microbe to erode the mother rocks, it also is the stockpile-storeroom and the exchange-storeroom of the farmland ecosystem nutrient cycle. Along with modern industrial development and human oneself activity’s increases, a great lot of materials-bearing heavy metal elements, such as waste water, exhaust gas , waste residue,inorganic fertilizers, pesticide pullution and so on, is brought to the earth’s surface environment and accumulated in the soil, it’s not only destroyed agro-ecosystem, but also affected the security of agricultural productions and has brought a series of ecology problem.The geological environment is an important physical condition for agro-ecosystem and a carrier for the survival of crops. Through the geological and geochemical investigation mapping of soil, water and atmosphere quality in the soil consolidation zone, the project has found out the characteristics of dispersion and enrichment of element distribution in the soil; The understanding of the relevant geochemical indicators, distribution and migration law of elements, which can provide basic data and scientific basis for improving the land utilization, stipulation of fertilization scheme by testing soil formulation, optimization of harmless agricultural products and green food base, adjustment of the agriculture planting structure and ensure the safety of agricultural products . Through the implementation of this project, it can set an example for applying effectively the results of agro-geological environmental survey to soil consolidation, development of agricultural production and improving life quality of both urban and rural residents.The "Golden Land Project", which is a concrete project that the Sichuan provincial government carries out for implementation of the national policies concerning agriculture, countryside and farmers. This project is a comprehensive improvement project for improving filed, water, road, forest and residence of countryside , improving utilizing structure of land and conditions of production and living , recovering ecological environment, newly adding effective arable land and improving the quality, land-use ratio and output capability of them. The agro-geological environmental survey is an important and basic part for the research and study of this project and a basic work serving for the sustainable development of local economy.For this reason, the thesis studies the farmland soil geochemica characteristics of Tongzi Town in Jiangan County, Yibin, China. The study covers regional geological setting; soil mineralogy; soil element geochemistry; soil nocuousness element geochemica characteristics; geochemica appraises of the farmland soil quality and so on.Baced on analytical data and synthetical studies, some conclusions can be drawn as follows:①The mother rocks of the soil-forming are purplish red mud sandstone and siltpelite of the Suinin Group, and deep-grey feldspathic-debris sandstone of the Shaximiao Group.②The compositions of purplish red farmland soil is similar to the mother rocks it, but the rice soil is not so. The rice soil is poor CaO and Na2O, and enrich Cd, Hg and S.③The heavy metal element Pb, Ni, Cu, Cd is enrichment in the farmland soil, and poor N, P and organic matters.④The acidity-alkalinity of the farmland soil: pH=6.5～8.5 in the Paoshadatu area, the Huangnitian area; pH<5.5 in the Shatu area, the Shatian area.⑤Here, Cd is enriching in the soil and surpassing I level of the State farmland soil, so it is belong to II level of the State farmland soil.As a whole, due to heavy metal Cd in the topsoil of the study area surpasses the first class standard of soil environment quality, it makes the soil environment quality in the study area become the national second-level soil. In the summated evaluation, the soil quality of study area is excellent.Based on the agrogeological investigation subproject of the "Golden Land Project" - the land consolidation zone in Tongzi Town of Jiang’an County, Tibin City and through the geochemical methods, this paper studies the geochemical characteristics of the farmland in this area. It lays heavy stress on topsoil, lateral longitudinal profile soil and vertical section plane soil. The characteristics and distribution of soil macroelement, microelement, nocuousness element and mineral composition are analyzed.During one-year implementation of this project, we have carries out the works of surface soil sample of the study area, lateral generalized section, longitudinal (shallow well) profile, the dust-fall of atmosphere, water environment measurement and the plant sampling. In view of this paper laying stress on farmland soil, it doesn’t involve the measurement results of dust-fall of atmosphere, water environment and plants. Through the test analysis of the collected soil sample, we have gotten comparatively profound knowledge about the soil macroelement, the microelement, the nocuousness element and other element and also understand the distributing characteristic and existing condition of them in the study area. It provides us a foundation for studying the soil quality.The agriculture geological investigation project of the land consolidation area in Tongzi Town of Jiang’an County, Yibin City is based on the spirit of No. 234 official letter of Sichuan people’s government [2005], No. 150 official letter of the Sichuan provincial financial investments department [2006] and NO. 1256 official letter of Sichuan Municipal Bureau of Land and Resources [2006] and regulation on carrying out agriculture geological investigation work in the "Golden Land Project" area , Sichuan Geological Investigation Institution undertake this project. It provides financial aid for this study. This paper is under the instruction of Prof. He Mingyou.更多还原