【作者】 林绍霞；

【导师】 林昌虎； 何腾兵；

【作者基本信息】 贵州大学 ， 环境科学， 2009， 硕士

【摘要】 本文针对贵州省农业生产过程中存在的农用物资的施用不当,从而对环境产生显著负面影响的问题。以贵州农业生产代表性区域为研究对象,以土壤为研究主体,通过普遍调查,探究目前贵州省农业非点源污染现状。同时采取典型区域布点采样的方法,检测了农业环境中的林地、旱地、水田、菜地几种利用类型的土壤环境质量,对比分析污染物在农业土壤中的积累特征。总结出农业生产中产生的环境污染物质在土壤环境中的赋存特征,以及农业生产中农用物资的不合理利用对土壤环境的危害程度,研究主要结论如下:(1)通过对贵州农业非点源污染现状的调查发现:随着农村人口、农村禽畜养殖业的不断增加与发展,农村污染物的产生量逐年递增。而另一方面,在农用物资不断增大的同时,农业生产耕地面积却逐年减少,单位面积耕地上污染物的负荷量逐渐增多,农用地的污染程度逐渐严重。(2)贵州农业生产物资的投入量相对于全国平均水平而言较小。但是,其农业生产环境在特殊的喀斯特岩溶条件下,即使很少的污染物投入量也易对农业土壤环境产生危害。(3)农业土壤受长期人为生产活动的影响,土壤的基本性质发生了变化,主要表现为:土壤pH值降低、砂粒含量增大、起保水持肥作用的细粉粒含量减少。土壤农业非点源污染物在贵州不同地区表现出不同的特征,主要表现为:南部和中部区域土壤中非点源污染物的含量较高、东部和北部区域偏低。(4)由于农业土地利用方式不同,土壤受纳农业生产中投入的外源物资的量及种类不同,土壤中赋存的污染物的种类各有差别。研究表明:在同一地区,全氮在耕作土壤中的含量水田>菜地>旱地;碱解氮菜地>水田>旱地;全磷菜地>旱地>水田;速效磷菜地>旱地>水田。土壤中重金属污染主要表现为Cd、Hg污染,其中Cd在土壤中累积量水田>菜地>旱地;Pb累积量旱地>水田>菜地。(5)由于耕地种植模式不同,以及不同作物对养分的需求量的差异,也造成土壤中非点源污染物在不同种植模式之间存在差异。主要表现为:旱地土壤氮素和磷素累积量以油菜/玉米、蔬菜/玉米种植模式偏高,其次为单季种植模式,重金属累积量以蔬菜/玉米、小麦/玉米种植模式偏高,水田土壤中氮素和磷素的累积以一年两熟模式高于单季稻种植模式,重金属累积则单季稻种植模式的土壤中较高。(6)土壤受农业非点源污染的程度与居民点之间距离的关系表现为:当距离<100m及>1000m时,土壤受污染的程度较严重;当距离处于100m～1000m之间时,土壤受污染的程度随距离的增大有缓和的趋势。(7)区域土壤中农业非点源污染物的含量与肥料施用水平有关,氮素含量随氮肥的施用量的增大而增加,磷素含量亦随磷肥施用量增大而增加,反之亦然。更多还原

【Abstract】 This study has discussed pollutant characteristics of agricultural non-point source pollution which produced by agriculture production activities in soil environment in Guizhou province,based on the problem that caused by the improper application of agricultural material in the process of agricultural production and its has significant and negative impact in environmental,used the soil in typical area of agricutural as subject to study. We research the current agricultural non-point source pollution in Guizhou through general survey,monitored the degree of pollution that caused by unreasonable use of agricultural substance through collected soil sample in typical area of agriculture production, the soil sample that we monitored including kinds of forestlands,dryland,paddy and vegetable soil. Through comparative analysis the characteristics of pollutant accumulation in soil environment,summary main conclusions were as follows:(1) Through general investigated the current of agricultural non-point source pollution in Guizhou we found:with the increasing of rural population and development of animal husbardry,the pollutants that yielded to rural were increasing yearly. On the other,the amount agricultural substance were used while the quantity of cultivated land was decreasing gradually,that lead to the load of pollutants per unit area of cultivated land were gradually increased, and the serious degree of pollution of agricultural land.(2) As the less-developed region in western of China, agricultural material inputs are below than the average of national in Guizhou, but its easily cause environment pollution because of it located in an unusual geological environment.(3) The elementary property of the soil have been changed, which affected by long-term human activities, mainly in the soil pH declined, content of sand increased and fine silt that can conservation fertilizer and water declined. The pollutants characteristics of agricultural non-point source pollution in soil environment in different regions of Guizhou performanced the southern and central regions more than eastern and northern in pollutant content.(4)Because of different land uses, the exogenous material capacity that from agricultural production have been varies. The results have been shown: the content of total nitrogen in soil of cultivation land were paddy>dryland>vegetable, alkali-hydrolyzed nitrogen were vegetable > paddy > dryland, total phosphorus vegetable> dryland> paddy, available phosphorus vegetable> dryland> paddy. Mainly heavy metal pollutant were Cd and Pb, the content of Cd in soil were paddy > vegetable> dryland, Pb cumulanted dryland> paddy > vegetable.(5)Difference planting patterns and nutrient requirement lead to the diversity non-point pollution in soil environment. the outcomes shows that the pollutant different in varity planting patterns, mainly the accumulation of nitrogen and phosphorus in the dryland were high in the patterns of corn/rapeseed rotation and then the single, heavy metal were highly accumulated in patterns of vegetable/corn and wheat/ corn. While in the paddy field were higher in two harvests in one year than single. And the heavy metals accumulated in single mode highly in soil.(6)The relationship between characteristics of contaminants content and the distance of settlements shows that while the distance less than 100m and beyond 1km, the pollutant content was higher than the distance among 100m to 1km.between 100m and 1km,the content of pollutants decreased with the father distance in soil environment.(7)The relationship between contaminants content and fertilization application level shows the uniformity with nitrogen content and nitrogen fertilizer and phosphorus and phosphate fertilizer.更多还原