CAJ | 학술논문

目的土壤重金属空间结构特征是土壤环境质量评价及重金属污染评价的基础。本文用地质统计学方法研究了柴达木盆地原生地和耕种50年的农田土壤镉的空间分布特征，对土壤镉进行质量评价，同时分析了农业耕种对土壤镉积累的影响，调查统计了灌溉水、肥料、农药等农业源土壤镉的输入量，为农田镉积累的风险预测提供参考。方法以柴达木盆地诺木洪农场的一块原生地（从未耕种过的土地，可以认为无化肥污染）和一块耕种地（已种植了50年的农田）为研究对象，从原生地采集22个土壤样本，耕种地采集50个土壤样本进行镉含量的测定，同时检测灌溉水、农药、化肥中的镉含量，并进行每年农田输入量的统计。用Excel软件进行数据处理，反比权重法（ IDW，Inverse Distance Weighting）插值，GIS9.3进行空间分析和图像处理；以单项污染指数法评价土壤镉质量，评价模式为Pi ＝Ci／Si （ Pi 为污染物镉的单项污染指数，Ci 为污染物镉的实测数据，Si 为污染物的评价标准）。评价标准分别以农业部公布的行业标准《无公害食品枸杞生产技术规程》（ NY／T 5249－2004）和《绿色食品枸杞》（NY／T1051－2006）产地环境标准要求下的《绿色食品产地环境技术条件》（NY／T 391－2000）为依据。依据农业源土壤镉输入量，以土壤现状值为起点，以绿色食品标准限量值为终点，测算输入量积累突破两端差值的年限。结果原生地22个土壤样品的镉平均含量为0.30 mg／kg，是土壤背景值的两倍（0.14 mg／kg），达到无公害食品（0.60 mg／kg）和绿色食品（0.40 mg／kg）标准；种植50年农田的50个土壤样品的镉平均含量为0.43 mg／kg，是土壤背景值的3倍，达到无公害食品标准，但超过绿色食品标准。用于灌溉的河水的镉含量为0.0036 ng／kg。检测生产中使用的15种农药和7种肥料，其中的镉导致每年土壤镉增加3444 mg／hm2。最严重的污染源是鸡粪，施入土壤后每年导致土壤镉增加2025 mg／hm2，其次依次为复合肥（使土壤镉增加576 mg／hm2），磷酸二铵（增加432 mg／hm2），有机肥（增加360 mg／hm2）。结论以小尺度空间分布和全量统计研究的诺木洪农场土壤镉含量这一单一指标衡量，可以看出诺木洪原生地土壤是清洁的，能够满足无公害、绿色食品的生产；但是研究选择的多年耕种田已经遭到重金属镉的污染，只能达到无公害食品标准，而达不到绿色食品标准。现行生产中的施肥措施是导致诺木洪土壤重金属镉污染的一个重要因素，其中鸡粪对镉污染的贡献最大，其次是复合肥、磷酸二铵和有机肥。如果继续现在这种耕种方式，以现有的原生地镉含量均值为0.30 mg／kg进行计算，76.3年后该土地镉含量将超过0.40 mg／kg的绿色标准上限。目的土壤重金屬空間結構特徵是土壤環境質量評價及重金屬汙染評價的基礎。本文用地質統計學方法研究瞭柴達木盆地原生地和耕種50年的農田土壤鎘的空間分佈特徵，對土壤鎘進行質量評價，同時分析瞭農業耕種對土壤鎘積纍的影響，調查統計瞭灌溉水、肥料、農藥等農業源土壤鎘的輸入量，為農田鎘積纍的風險預測提供參攷。方法以柴達木盆地諾木洪農場的一塊原生地（從未耕種過的土地，可以認為無化肥汙染）和一塊耕種地（已種植瞭50年的農田）為研究對象，從原生地採集22箇土壤樣本，耕種地採集50箇土壤樣本進行鎘含量的測定，同時檢測灌溉水、農藥、化肥中的鎘含量，併進行每年農田輸入量的統計。用Excel軟件進行數據處理，反比權重法（ IDW，Inverse Distance Weighting）插值，GIS9.3進行空間分析和圖像處理；以單項汙染指數法評價土壤鎘質量，評價模式為Pi ＝Ci／Si （ Pi 為汙染物鎘的單項汙染指數，Ci 為汙染物鎘的實測數據，Si 為汙染物的評價標準）。評價標準分彆以農業部公佈的行業標準《無公害食品枸杞生產技術規程》（ NY／T 5249－2004）和《綠色食品枸杞》（NY／T1051－2006）產地環境標準要求下的《綠色食品產地環境技術條件》（NY／T 391－2000）為依據。依據農業源土壤鎘輸入量，以土壤現狀值為起點，以綠色食品標準限量值為終點，測算輸入量積纍突破兩耑差值的年限。結果原生地22箇土壤樣品的鎘平均含量為0.30 mg／kg，是土壤揹景值的兩倍（0.14 mg／kg），達到無公害食品（0.60 mg／kg）和綠色食品（0.40 mg／kg）標準；種植50年農田的50箇土壤樣品的鎘平均含量為0.43 mg／kg，是土壤揹景值的3倍，達到無公害食品標準，但超過綠色食品標準。用于灌溉的河水的鎘含量為0.0036 ng／kg。檢測生產中使用的15種農藥和7種肥料，其中的鎘導緻每年土壤鎘增加3444 mg／hm2。最嚴重的汙染源是鷄糞，施入土壤後每年導緻土壤鎘增加2025 mg／hm2，其次依次為複閤肥（使土壤鎘增加576 mg／hm2），燐痠二銨（增加432 mg／hm2），有機肥（增加360 mg／hm2）。結論以小呎度空間分佈和全量統計研究的諾木洪農場土壤鎘含量這一單一指標衡量，可以看齣諾木洪原生地土壤是清潔的，能夠滿足無公害、綠色食品的生產；但是研究選擇的多年耕種田已經遭到重金屬鎘的汙染，隻能達到無公害食品標準，而達不到綠色食品標準。現行生產中的施肥措施是導緻諾木洪土壤重金屬鎘汙染的一箇重要因素，其中鷄糞對鎘汙染的貢獻最大，其次是複閤肥、燐痠二銨和有機肥。如果繼續現在這種耕種方式，以現有的原生地鎘含量均值為0.30 mg／kg進行計算，76.3年後該土地鎘含量將超過0.40 mg／kg的綠色標準上限。
목적토양중금속공간결구특정시토양배경질량평개급중금속오염평개적기출。본문용지질통계학방법연구료시체목분지원생지화경충50년적농전토양력적공간분포특정，대토양력진행질량평개，동시분석료농업경충대토양력적루적영향，조사통계료관개수、비료、농약등농업원토양력적수입량，위농전력적루적풍험예측제공삼고。방법이시체목분지낙목홍농장적일괴원생지（종미경충과적토지，가이인위무화비오염）화일괴경충지（이충식료50년적농전）위연구대상，종원생지채집22개토양양본，경충지채집50개토양양본진행력함량적측정，동시검측관개수、농약、화비중적력함량，병진행매년농전수입량적통계。용Excel연건진행수거처리，반비권중법（ IDW，Inverse Distance Weighting）삽치，GIS9.3진행공간분석화도상처리；이단항오염지수법평개토양력질량，평개모식위Pi ＝Ci／Si （ Pi 위오염물력적단항오염지수，Ci 위오염물력적실측수거，Si 위오염물적평개표준）。평개표준분별이농업부공포적행업표준《무공해식품구기생산기술규정》（ NY／T 5249－2004）화《록색식품구기》（NY／T1051－2006）산지배경표준요구하적《록색식품산지배경기술조건》（NY／T 391－2000）위의거。의거농업원토양력수입량，이토양현상치위기점，이록색식품표준한량치위종점，측산수입량적루돌파량단차치적년한。결과원생지22개토양양품적력평균함량위0.30 mg／kg，시토양배경치적량배（0.14 mg／kg），체도무공해식품（0.60 mg／kg）화록색식품（0.40 mg／kg）표준；충식50년농전적50개토양양품적력평균함량위0.43 mg／kg，시토양배경치적3배，체도무공해식품표준，단초과록색식품표준。용우관개적하수적력함량위0.0036 ng／kg。검측생산중사용적15충농약화7충비료，기중적력도치매년토양력증가3444 mg／hm2。최엄중적오염원시계분，시입토양후매년도치토양력증가2025 mg／hm2，기차의차위복합비（사토양력증가576 mg／hm2），린산이안（증가432 mg／hm2），유궤비（증가360 mg／hm2）。결론이소척도공간분포화전량통계연구적낙목홍농장토양력함량저일단일지표형량，가이간출낙목홍원생지토양시청길적，능구만족무공해、록색식품적생산；단시연구선택적다년경충전이경조도중금속력적오염，지능체도무공해식품표준，이체불도록색식품표준。현행생산중적시비조시시도치낙목홍토양중금속력오염적일개중요인소，기중계분대력오염적공헌최대，기차시복합비、린산이안화유궤비。여과계속현재저충경충방식，이현유적원생지력함량균치위0.30 mg／kg진행계산，76.3년후해토지력함량장초과0.40 mg／kg적록색표준상한。
Objectives]Analysis of spatial distribution of heavy metals in soil is a foundation of evaluating soil environmental quality and heavy metal pollution.This study characterized and mapped the spatial distribution of total and available cadmium in original land ( native soil that had never been farmed) and farmland ( that had been cultivated for 50 years) soils in the Qaidam Basin using geostatistical methods.According to this, soil cadmium quality and impact of farming on the accumulation of cadmium in soil were evaluated.The primary agricultural sources of cadmium accumulation in soil were examined, including irrigation water, pesticides and fertilizers, and risk of cadmium accumulation in soils was predicted.[Methods]In study fields, original land and farmland were selected at the Nuomuhong farm in Qaidam Basin.The original land site has never been cultivated and thus can be considered to be free from fertilizer pollution.The farmland is irrigated and has been cultivated for 50 years.22 soil samples from original land and 50 soil samples from farmland were collected, and soil cadmium contents were analyzed.Irrigation water, pesticides and fertilizers which are the primary agricultural sources of cadmium accumulation in soil were also examined.Excel was used for data statistics, and inverse distance weighting ( IDW) interpolation was used in the spatial analysis.ArcGIS (9.3) software was used for image processing.We evaluated the soil cadmium quality using a single pollutant index method, Pi=Ci/Si ( Pi stands for the index of the single pollutant Cadmium, Ci denotes the test data, and Si is the evaluation standard) .The evaluation standards conform to the ‘Pollution-Free Food Medlar Production Technology Regulations’ ( NY/T 5249-2004 ) and the‘Green Food Original Place Environmental Technology Condition ’ ( NY/T 391-2000 ) , which are based on the original environmental standards issued by the National Ministry of Agriculture.Risk prediction of cadmium accumulation in soil due to agriculture: First, we calculated the statistical sum of all cadmium carried via irrigation water, pesticides and fertilizers, and then calculated the annual soil cadmium concentration.Second, we calculated the difference between the original land soil cadmium concentration and the standard, and calculated the time at which the agricultural cadmium accumulation would reach this difference.[Results]In the original land soils, the mean cadmium content is 0.30 mg/kg, which is about twice of the background level ( 0.14 mg/kg ) , and meet the related values in both the pollution-free food standard (0.60 mg/kg) and the green food standard (0.40 mg/kg) . In the farmland soils, the mean cadmium content is 0.43 mg/kg, about three times of the background level, and is lower than the pollution-free food standard, but higher than the green food standard.The cadmium content in irrigation water from river is 0.0036 ng/kg.Fifteen kinds of pesticides, fungicides, herbicides and plant hormones are detected.Seven kinds of fertilizers are analyzed.The most serious source of pollution is chicken manure, which contributes 2025 mg/ha per year, followed by compound fertilizer (576 mg/ha per year) , diammonium phosphate ( DAP) (432 mg/ha per year) , and organic fertilizer (360 mg/ha per year) .[Conclusions] A cadmium index was used to examine the small-scale distribution of cadmium pollution in Nuomuhong farm soils and to calculate statistics.The results indicate that the original land soils at the Nuomuhong farm meet the Pollution-Free Standard and the Green Food Standard.However, in land that has been farmed for more than 50 years, cadmium has accumulated.This land still meets the Pollution-Free Standard, but does not meet the Green Food Standard. Fertilization is an important source of cadmium accumulation in the Nuomuhong farm soils.Among the fertilizers used, chicken manure is the dominant contributor, followed by compound fertilizer, DAP, and organic fertilizer.If agricultural practices at the Nuomuhong farm do not change, the cadmium content in original land will exceed the green food standard’ s upper limit of 0.40 mg/kg after 76.3 years.