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1.
北京市不同土地利用类型的土壤砷含量特征 总被引：42，自引：4，他引：42
通过对北京市菜地、稻田、果园、绿化地、麦地以及自然土壤6种土地利用类型共500 个土壤样品的调查分析,探讨了不同土地利用方式对土壤砷积累的影响。与北京市土壤背景值相比,砷在土壤中均有不同程度的增加,累积现象比较普遍。在6种土地利用类型中,自然土壤的砷含量最低,最接近背景值;菜地和稻田的土壤砷含量的增加最为显著。以基线值为标准,北京市涉及土地利用的土壤砷含量总体超标率为1.8%;6种土地利用类型中,菜地、果园、麦地三种土壤砷含量的超标率分别为2.6%、2.7%、0.7%。土壤砷含量的平均值由高到低分别为:稻田>绿化地>菜地>果园>麦地>自然土壤。 相似文献
2.
北京市不同土地利用方式下土壤铅的积累 总被引：65，自引：3，他引：62
通过对北京市菜地、稻田、果园、绿化地、麦地以及自然土壤等土地利用类型600个土壤的监测分析,探讨了不同土地利用方式对土壤铅积累的影响。研究结果表明,全部土壤样品中铅浓度的几何平均值为26.6 mg/kg,显著高于北京市土壤背景值 (24.6 mg/kg),呈现出明显的积累趋势。不同土地利用方式对土壤铅积累有明显影响,其中绿化地土壤的平均铅浓度最高,依次为果园、菜地、稻田、自然土壤,麦地平均铅浓度最低,绿化地土壤的铅浓度要显著高于除果园外的其他土地利用类型。果园土壤的铅浓度同样与其他大多数土地利用类型的土壤有较显著的差别。以基线值为标准,除自然土壤外,其他5种土地利用类型下均有不同程度的样品超标：果园超标率最高 (21.4%),其他分别为绿化地18.2%,菜地11.1%,稻田8.3%,麦地5.2%;样品总体的超标率为7.2%。从行政区域来看,城区土壤的铅浓度高于近郊区,近郊区要明显高于远郊区土壤,超标样点主要分布在昌平、朝阳、大兴、丰台、海淀、石景山区等城区或近郊区,因而土壤铅浓度有从城市中心区向外逐渐降低的趋势。在本研究中,大气沉降、垃圾填埋以及农药施用等人类活动可能是影响不同土地利用类型下土壤铅积累浓度的重要原因。 相似文献
3.
城乡交错带土地利用变化对土壤养分的影响--以北京市大兴区为例 总被引：11，自引：0，他引：11
以北京市大兴区为城乡交错带的分析样区,对1982年、2000年土地利用方式变化和两期不同土地利用方式的土壤养分变化情况进行分析。结果表明:与1982年相比,2000年土壤有机质含量在不同土地利用方式下增加的顺序为:果园>水浇地>稻田>菜地>林地>旱地; 土壤全氮含量增加的顺序为:稻田>菜地>水浇地>果园>旱地>林地;土壤碱解效氮含量增加的顺序为稻田>水浇地>菜地>果园>旱地>林地;土壤速效磷含量增加的顺序为果园>水浇地>稻田>旱地>菜地>林地;土壤速效钾含量在不同土地利用方式下变化规律为, 在果园和稻田中略有增加,在其他利用方式中有不同程度降低。水稻田转变为水浇地、菜地、果园后,土壤有机质、全氮、碱解氮含量增加幅度顺序为旱地>果园>水浇地>菜地;速效磷含量增加的顺序为果园>水浇地>菜地>旱地。旱地转变为果园、水浇地后,除速效钾含量降低外,其他养分含量都有不同程度的提高。沙荒地转变为旱地、水浇地、菜地、果园、林地后,除速效钾含量降低外,其他养分含量都有不同程度的增加。 相似文献
4.
集约化农区土地利用变化对土壤养分的影响——以河北省曲周县为例 总被引：58，自引：1，他引：57
以河北省曲周县为集约化农区的分析样区,通过对1980年、1999年土地利用类型变化和2期不同用地类型的土壤养分变化进行分析。结果表明：曲周县1980~1999年之间的土地利用类型以水浇地、旱地、菜地、园地、林地等农业用地类型为主,1980年农业用地类型占土地总面积的77.47%,1999年的农业利用类型占土地总面积的77.43%;但是土地利用类型也存在着转化,转化的顺序为荒草地向旱地、水浇地、菜地方向转化,旱地向水浇地、菜地方向转化;1980年土壤养分含量在不同用地类型间的变化顺序为水浇地>旱地>荒草地,差异幅度在2%～18%之间,1999年土壤养分含量在不同用地类型间的变化顺序为菜地>水浇地>旱地,差异幅度在18%～690%之间;2期对比分析表明,土壤养分含量除速效钾外不仅在相同用地类型之间增加幅度大,而且在转化后地用地类型之间也存在明显差异;土壤有机质、全氮、速效磷含量在不同土地利用类型中的变化顺序为菜地>水浇地>旱地>荒草地,速效钾含量变化的顺序为旱地>荒草地>菜地>水浇地。 相似文献
5.
粤北岩溶区不同土地利用方式对土壤钙离子的影响 总被引：4，自引：0，他引：4
在广东省英德市九龙镇峰林平原选择峰林坡麓灌丛、积水洼地、砂糖橘林、竹林、菜地、稻田6种不同土地利用类型,采集不同土地利用方式下不同深度的土壤,利用原子吸收分光光度计测定了土壤全钙、交换态钙和水溶性钙质量分数,结果表明：1）菜地、稻田、砂糖橘林和竹林土壤厚度显著大于自然坡麓和积水洼地;2）岩溶积水环境中（积水洼地和稻田）土壤全钙质量分数平均超过59 g/kg;其次为坡麓土壤,平均为20.83 g/kg;人工耕作的砂糖橘林和菜地土壤全钙质量分数分别降低至3.51和2.76 g/kg,而相邻的非岩溶区土壤的全钙质量分数仅为1.43 g/kg;3）耕地施肥会增加土壤的交换态钙和水溶性钙质量分数,菜地和砂糖橘林土壤交换态钙离子、水溶性钙占全钙的比例分别为38.04%、23.08%和1.41%、0.88%,而积水洼地和坡麓灌丛只有7.86%、6.87%和0.25%、0.46%。由于菜地和砂糖橘林的全钙质量分数降低,而交换态钙和水溶性钙质量分数增加会进一步加剧钙元素流失;4）不同土地利用类型土壤全钙、交换态钙和水溶性钙质量分数随深度变化呈波状下降趋势,积水洼地与稻田钙随深度的变化远比菜地、砂糖橘林和竹林剧烈;5）土壤厚度、岩石裸露率、坡度相互呈显著负相关,土壤全钙、交换态钙、水溶性钙之间均呈显著正相关,岩石裸露率与交换态钙呈显著负相关,水、土壤厚度、岩石裸露率与坡度共同决定了土壤钙的分布和迁移。 相似文献
6.
上海市崇明岛农田土壤重金属的环境质量评价 总被引：21，自引：1，他引：20
通过对上海市崇明岛28个菜地土壤表层样品、65个稻田土壤表层样品及9个西瓜地土壤表层样品的分析测试,利用国家、行业和地方的相关标准评价了农田土壤重金属(Pb、Cd、Cr、As、Hg)的环境质量状况.研究发现:崇明岛农田土壤重金属的总体含量为Pb21.597 mg·kg-1、Cd 0.176 mg-kg-1、Cr 69.395 mg·kg-1、As 9.209 mg·kg-1、Hg O.128 mg·kg-1.与上海市土壤背景值相比,除Pb、Cr外,其余重金属平均含量均高于其背景值,Cd、As和Hg分别高出背景值33.O%、1.2%和26.3%.在GIS软件支持下,通过空间插值分析了研究区农田土壤重金属含量的空间分布特征,结果发现,农田土壤质量整体尚好,土壤生态率为1.26%,优良率为97.14%,合格率为1.47%,不合格率为0.12%.以背景值为标准,崇明岛农田土壤Pb、Cd、Cr、As、Hg的超标率分别为10.1%、85.7%、27.0%、55.4%、55.2%;3种土地利用类型中,菜地受重金属污染最为严重,这主要与菜地施用更多农药有关.崇明岛重金属的年沉降通量分别为Pb 7735.470 ug·m-2.a-1、Cd 208.432ug.m-2·a-1、As 2237.738 ug·m-2·a-1、Hg 52.783 ug·m-2·a-1,农作物秸秆焚烧处理是崇明岛大气重金属沉降的重要来源,大气沉降对崇明岛农田土壤重金属有较大的影响. 相似文献
7.
环鄱阳湖区农家菜地土壤重金属风险评价及来源分析 总被引：4，自引：0，他引：4
通过评价环鄱阳湖区10个县农家菜地土壤样品重金属的潜在生态风险,分析其与9个社会经济指标间的灰色关联度来探讨重金属的污染来源。结果显示,鄱阳湖区各菜地土壤中Cd的超标情况最严重,超标率达到90%,除部分地区Cu超标外,其余重金属均未超标。鄱阳湖区农家菜地土壤达到轻微生态风险,工业较发达地区重金属生态风险较大于工业落后地区,工业发展情况对湖区的空间污染分异有较大影响。蔬菜产量、工业发展情况、城镇化率、交通业发展情况和菜地土壤不同种重金属具有较高关联度,而地区生产总值、农药使用量对各种重金属含量的影响最弱。 相似文献
8.
海南岛东部地区土地利用方式对土壤有机碳与
易氧化有机碳的影响 总被引：3，自引：0，他引：3
以海南岛东部地区的4种土地利用方式（水田、抛荒地、果园、橡胶林地）的土壤为研究对象，通过对其SOC（土壤有机碳）和ROC（土壤易氧化有机碳）质量分数的测定，分析不同土地利用方式下SOC以及ROC的分布特征。结果表明：研究区的土地利用方式对SOC与ROC具有显著影响，土地利用方式通过影响植被凋落物、根系以及耕作方式、施肥收割等管理措施影响SOC及ROC的分布特征。就整个土壤剖面（0~30 cm）而言，不同土地利用方式下SOC质量分数的分布特征表现为水田＞抛荒地＞果园＞橡胶林地；各土地利用方式下SOC在表层土壤中质量分数最高，并随着土壤层的加深逐渐递减。水田、果园和橡胶林地土壤的ROC质量分数随着土壤深度的加深而逐渐降低，抛荒地呈现出先减少后增加的趋势。不同土地利用方式下土壤ROC质量分数表现为抛荒地＞水田＞果园＞橡胶林地。ROC质量分数的高低顺序与SOC质量分数基本相同。土壤的SOC质量分数是影响ROC质量分数变化的重要因素，相关性分析结果表明：水田、抛荒地和橡胶林地的SOC与ROC质量分数呈极显著正相关，而果园的SOC与ROC质量分数呈显著正相关。4种土地利用方式中水田土壤ROC的分配比例较低，说明水田的SOC稳定性相对于其他土地利用方式较高，有利于土壤碳的储存。 相似文献
9.
海南省农产品产地土壤环境质量评价 总被引：2，自引：0，他引：2
采用单项质量指数与综合质量指数相结合的方法,对海南省农产品产地的土壤进行了重金属Cd、 Hg、 As、 Pb、 Cr、 Cu、 Zn和Ni含量的抽样调查分析与评价。结果表明,海南省农产品产地土壤重金属的平均含量均低于“HJ 332-2006”（食用农产品产地环境质量评价标准）规定的限值,土壤重金属的单项质量指数均≤0．7,综合质量指数为0．33,土壤环境质量均为1级,属于清洁水平,适宜发展无公害农产品。同时发现,部分产地的土壤中重金属含量有超标现象,海口有部分样品Cd、 Hg、 Cr、 Cu和Ni超标,三亚有部分样品Cd和Hg超标,儋州、澄迈均以Ni超标为主,琼海有部分样品Cr、 Cu和Ni超标。重金属含量之间多呈正相关关系,其中As与Pb、 As与Cu、 Cr与Zn、 Cu与Zn之间的相关性达到了极显著水平, Cd与Hg、 Pb、 Ni, Pb与Cu, Cr与Cu, Cu与Ni之间的相关性达到了显著水平。大部分监测点土壤中重金属含量均高于海南省水稻土自然背景值,表明在监测点土壤中产生了重金属累积。 相似文献
10.
粤东北山区不同土地利用类型红壤团聚体及其有机碳分布特征 总被引：1，自引：1，他引：0
以天然常绿阔叶林地、柚果园、茶园、人工桉树林地和旱地为研究对象,采用野外调查和室内实验分析相结合的方法,研究了粤东北山区红壤团聚体及其有机碳的分布特征.结果表明:①研究区5种土地利用类型红壤各级风干团聚体占总团聚体的比例均为粒径＞5 mm的最大,阔叶林地各级风干团聚体含量基本上高于其他土地利用类型.湿筛后,阔叶林地和果园土壤团聚体水稳性较好,表土层粒径＞ 0.25 mm的水稳性团聚体含量均在70％以上;而茶园、桉树林和旱地各土层土壤水稳性团聚体明显减少,结构体破坏率高.②不同粒级红壤团聚体有机碳含量在不同土地类型有明显差异,总体上表现为阔叶林地最高,果园次之,早地与桉树林地最低.随土层增加团聚体有机碳含量呈逐渐减小趋势,阔叶林地团聚体有机碳含量垂直变化最大,减幅达46.25％;桉树林地和旱地减幅最小,分别为29.58％和12.54％.③不同粒径团聚体的百分含量与其有机碳含量之间存在线形关系,阔叶林地和果园土壤＞5 mm、5～2 mm团聚体与其有机碳含量之间呈高度或显著正相关.茶园、桉树林地和旱地则较小粒径的团聚体与其有机碳含量之间呈高度或显著正相关.地带性森林植被的营造和保护有利于土壤团聚体的形成以及土壤有机碳的积累与稳定. 相似文献
11.
SUN Chao BI Chunjuan CHEN Zhenlou WANG Dongqi ZHANG Cui SUN Yuedi YU Zhongjie ZHOU Dong 《地理学报》2010,20(1):135-147
The environmental quality of heavy metals (Pb, Cd, Cr, As, Hg) in agricultural surface soil of Chongming Island was assessed by national, local and professional standards based on a large scale investigation, in which 28 samples from vegetable plots, 65 samples from paddy fields and 9 samples from watermelon fields were collected from whole island area. Results showed that the average concentration of Pb, Cd, Cr, As and Hg was 21.6 mg·kg-1 , 0.176 mg·kg-1, 69.4 mg·kg-1, 9.209 mg·kg-1 and 0.128 mg·kg-1, respectively. Compared with the background value of Shanghai City soil, except for Pb and Cr, all the other heavy metals average concentrations in Chongming Island agricultural surface soil exceeded their corresponding natural-background values. The concentrations of Cd, As and Hg were 33.0%, 1.2% and 26.3% higher than the background value of Shanghai City, respectively. In addition, inverse distance interpolation (IDW) tool of GIS was also applied to study the spatial variation of heavy metals. The results indicated that most of agricultural soil quality was good, and the ratio of ecological, good soil, certified soil and disqualified soil were 1.26%, 97.1%, 1.47% and 0.12%, respectively. About 10.1%, 85.7%, 27.0%, 55.4% and 55.2% soil samples exceeded the Pb, Cd, Cr, As and Hg background value of Shanghai City, respectively. Among these three land use type soils, vegetable soil was most seriously polluted by heavy metals, which is probably related to the over-application of pesticides. The annual deposition fluxes of Pb, Cd, As and Hg were 7736 μg·m-2·a-1, 208 μg·m-2·a-1, 2238 μg·m-2·a-1 and 52.8 μg·m-2·a-1, respectively. Crop straw burning was the important source of heavy metals of atmospheric deposition, and atmospheric deposition contributed a lot to heavy metals in agricultural soil in Chongming Island. 相似文献
12.
不同土地利用方式对岩溶作用的影响——以广西弄拉峰丛洼地岩溶系统为例 总被引：22，自引：1，他引：21
土地利用可使土壤理化性质产生一系列的变化,从而影响到岩溶作用的方向和强度。以广西马山县弄拉典型峰丛洼地区为例,通过野外溶蚀试片法探讨了不同土地利用方式对岩溶作用的影响。结果表明不同土地利用类型土下溶蚀量存在显著差异。林地与园地土下溶蚀量极大部分大于20 mg/a,明显高于灌丛地及 (休) 耕地 (多小于20 mg/a)。总体上,溶蚀量从大到小依次为园地、林地、耕地、休耕地与灌丛。其中至少有两个主要控制因素：土壤有机质和土壤CO2：林地和园地土下溶蚀作用主要受前者控制,土壤有机质含量越高、pH越低,土下溶蚀量越大。在耕地与灌丛条件下由于土壤有机质含量较低,土下溶蚀量主要受土壤CO2控制。 相似文献
13.
WANG Lixia GUO Zhaohui XIAO Xiyuan CHEN Tongbin LIAO Xiaoyong SONG Jie WU Bin 《地理学报》2008,18(3):353-362
A total of 219 agricultural soil and 48 vegetable samples were collected from the midstream and downstream of the Xiangjiang River (the Hengyang–Changsha section) in Hunan Province. The accumulation characteristics, spatial distribution and potential risk of heavy metals in the agricultural soils and vegetables were depicted. There are higher accu-mulations of heavy metals such as As, Cd, Cu, Ni, Pb and Zn in agricultural soils, and the contents of Cd (2.44 mg kg-1), Pb (65.00 mg kg-1) and Zn (144.13 mg kg-1) are 7.97, 3.69 and 1.63 times the corresponding background contents in soils of Hunan Province, respectively. 13.2% of As, 68.5% of Cd, 2.7% of Cu, 2.7% of Ni, 8.7% of Pb and 15.1% of Zn in soil sam-ples from the investigated sites exceeded the maximum allowable heavy metal contents in the China Environmental Quality Standard for Soils (GB15618-1995, Grade II). The pollution characteristics of multi-metals in soils are mainly due to Cd. The contents of As, Cd, Cu, Pb and Zn in vegetable soils are significantly higher than the contents in paddy soils. 95.8%, 68.8%, 10.4% and 95.8% of vegetable samples exceeded the Maximum Levels of Contami-nants in Foods (GB2762-2005) for As, Cd, Ni and Pb concentrations, respectively. There are significantly positive correlations between the concentrations of Cd, Pb and Zn in vegetables and the concentrations in the corresponding vegetable soils (p<0.01). It is very necessary to focus on the potential risk of heavy metals for food safety and human health in agricultural soils and vegetables in the midstream and downstream of the Xiangjiang River, Hunan Province of China. 相似文献
14.
湘江中下游农田土壤和蔬菜的重金属污染 总被引：11，自引：0，他引：11
A total of 219 agricultural soil and 48 vegetable samples were collected from the midstream and downstream of the Xiangjiang River（the Hengyang-Changsha section）in Hunan Province.The accumulation characteristics,spatial distribution and potential risk of heavy metals in the agricultural soils and vegetables were depicted.There are higher accumulations of heavy metals such as As,Cd,Cu,Ni,Pb and Zn in agricultural soils,and the contents of Cd（2.44 mg kg^-1 ）,Pb（65.00 mg kg^-1 ）and Zn（144.13 mg kg^-1 ）are 7.97,3.69 and 1.63 times the corresponding background contents in soils of Hunan Province,respectively. 13.2%of As,68.5%of Cd,2.7%of Cu,2.7%of Ni,8.7%of Pb and 15.1%of Zn in soil samples from the investigated sites exceeded the maximum allowable heavy metal contents in the China Environmental Quality Standard for Soils（GB15618-1995,Grade Ⅱ）.The pollution characteristics of multi-metals in soils are mainly due to Cd.The contents of As,Cd,Cu,Pb and Zn in vegetable soils are significantly higher than the contents in paddy soils.95.8%, 68.8%,10.4%and 95.8%of vegetable samples exceeded the Maximum Levels of Contaminants in Foods（GB2762-2005）for As,Cd,Ni and Pb concentrations,respectively.There are significantly positive correlations between the concentrations of Cd,Pb and Zn in vegetables and the concentrations in the corresponding vegetable soils（p〈0.01）.It is very necessary to focus on the potential risk of heavy metals for food safety and human health in agricultural soils and vegetables in the midstream and downstream of the Xiangjiang River,Hunan Province of China. 相似文献
15.
16.
贵州猫跳河流域土地利用变化和土壤侵蚀(英文) 总被引：4，自引：2，他引：2
Due to the extremely poor soil cover, a low soil-forming rate, and inappropriate intensive land use, soil erosion is a serious problem in Guizhou Province, which is located in the centre of the karst areas of Southwest China. In order to bring soil erosion under control and restore environment, the Chinese Government has initiated a serious of ecological rehabilitation projects such as the Grain-for-Green Programme and Natural Forest Protection Program and brought about tremendous influences on land-use change and soil erosion in Guizhou Province. This paper explored the relationship between land use and soil erosion in the Maotiao River watershed, a typical agricultural area with severe soil erosion in central Guizhou Province. In this study, we analyzed the spatio-temporal dynamic change of land-use type in Maotiao River watershed from 1973 to 2007 using Landsat MSS image in 1973, Landsat TM data in 1990 and 2007. Soil erosion change characteristics from 1973 to 2007, and soil loss among different land-use types were examined by integrating the Revised Universal Soil Loss Equation (RUSLE) with a GIS environment. The results indicate that changes in land use within the watershed have significantly affected soil erosion. From 1973 to 1990, dry farmland and rocky desertified land significantly increased. In contrast, shrubby land, other forestland and grassland significantly decreased, which caused accelerated soil erosion in the study area. This trend was reversed from 1990 to 2007 with an increased area of land-use types for ecological use owing to the implementation of environmental protection programs. Soil erosion also significantly varied among land-use types. Erosion was most serious in dry farmland and the lightest in paddy field. Dry farmland with a gradient of 6°-25° was the major contributor to soil erosion, and conservation practices should be taken in these areas. The results of this study provide useful information for decision makers and planners to take sustainable land use management and soil conservation measures in the area. 相似文献
17.
上海市崇明岛农田土壤重金属的环境质量评价(英文) 总被引：1，自引：0，他引：1
The environmental quality of heavy metals (Pb,Cd,Cr,As,Hg) in agricultural surface soil of Chongming Island was assessed by national,local and professional standards based on a large scale investigation,in which 28 samples from vegetable plots,65 samples from paddy fields and 9 samples from watermelon fields were collected from whole island area. Results showed that the average concentration of Pb,Cd,Cr,As and Hg was 21.6 mg·kg-1,0.176 mg·kg-1,69.4 mg·kg-1,9.209 mg·kg-1 and 0.128 mg·kg-1,respectively. Compared with the background value of Shanghai City soil,except for Pb and Cr,all the other heavy metals average concentrations in Chongming Island agricultural surface soil exceeded their corresponding natural-background values. The concentrations of Cd,As and Hg were 33.0%,1.2% and 26.3% higher than the background value of Shanghai City,respectively. In addition,inverse distance interpolation (IDW) tool of GIS was also applied to study the spatial variation of heavy metals. The results indicated that most of agricultural soil quality was good,and the ratio of ecological,good soil,certified soil and disqualified soil were 1.26%,97.1%,1.47% and 0.12%,respectively. About 10.1%,85.7%,27.0%,55.4% and 55.2% soil samples exceeded the Pb,Cd,Cr,As and Hg background value of Shanghai City,respectively. Among these three land use type soils,vegetable soil was most seriously polluted by heavy metals,which is probably related to the over-application of pesticides. The annual deposition fluxes of Pb,Cd,As and Hg were 7736 μg.m-2.a-1,208 μg.m-2.a-1,2238 μg.m-2.a-1 and 52.8 μg.m-2.a-1,respectively. Crop straw burning was the important source of heavy metals of atmospheric deposition,and atmospheric deposition contributed a lot to heavy metals in agricultural soil in Chongming Island. 相似文献