Soil Environment Ecological Quality Of The Typical Metal Smelting Area In The South Foot Of Taihang Mountain

As a livestock production support of the food and various kinds of major agricultural, soil resources provide energy substances necessary for survival, it is directly related to the human condition. And therefore, the evaluation of farmland soil environmental quality and soil- crops system correlation have an important reality meaning and provide scientific guidance for producing agricultural products environmental safety.Taking the metal smelting area in Taihang Mountain for example, the content of soil-crops heavy metal Pb, Cd, As, Hg and Cr in the surrounding farmland were tested and analyzed by traditional statistical software such as SPSS, geostatistics and Arc GIS. The study was focused on the relationship between the total contents, the available contents of soil and the contents of crops and then analyzed the characteristics of the content of heavy metals in farmland soil, the soil environment quality, the pollution situation, the characteristics heavy metal content in crops(wheat, corn) and the relationship between the total and available content in the soil. The conclusions show:(1)The average content of heavy metals in soil samples in the study area were full amount: Pb 142.32 mg · kg-1, Cd 1.52 mg · kg-1, As 18.15 mg · kg-1, Hg 0.145 mg · kg-1, Cr 76.35 mg · kg-1, higher than the local background value. And the heavy metals have large spatial variability. Based on the soil environmental quality standards, there are 5 single factor pollution indices of Pb, Cd, As, Hg and Cr, which are 1.78,2.16,0.70,0.11 and 0.3. Their over standard rate respectively are 80.13%, 88.08%, 11.92%, 0.66% and 6.62%, This proved the study area was polluted by heavy metals Cd and Pb. The Nemerow pollution evaluation results was 1.89, belonging to light pollution levels. The Space Kriging results showed that heavy metal Hg and Cr in the study area are in a safe state without pollution. The heavy metals Pb, Cd and As showed that with the distance from mining companies and the pollution gradually decreased, the more polluting region was on the status of the study area in the northwest and central business-intensive areas.(2)Based on the Limits of contaminants in foods GB 2762-2012, the heavy metal content of Pb, Cd, As, Hg in the wheat respectively are 0.49,0.21,0.15 and 0.005 7mg · kg-1. The average content of Pb and Cd value exceeds the standard limit. The heavy metal content of Pb, Cd, As, Hg in the corn respectively are 0.19, 0.036, 0.082, 0.000 9mg · kg-1 and both lower than the standard limit. But there were still some sample situations and heavy metal content exceeding the limits. wheat Grain four heavy metals were higher than corn grain heavy metal, heavy metal accumulation ability legend wheat higher than wheat.(3) In terms of soil-crops relevance of the heavy metal content, the heavy metal has certain positive correlation in wheat grain and the total content. The correlation coefficient order was Cd> Hg> As> Pb, and the correlation coefficient between the content of available descending order Cd> Pb> As> Hg. The content of heavy metal Cd in wheat was significantly positively related to the level, and the Cd accumulation was significantly higher than other heavy metals. The correlation coefficient R2 of content of heavy metal between corn grain and soil are less than 0.1.There is a negative correlation between Hg content and even whole correlation is not significant. The bioaccumulation factor of heavy metals Cd in corns was still significantly larger than the other three kinds of heavy metals. This shows that Cd accumulation in crops easier in the study area.(4) In soil heavy metal total content, effective state content, crop quantitative relationship between heavy metal content analysis, it found that: there is the possibility of exogenous atmospheric dust pollution, water pollution, heavy metal content of As and Hg content in crops is greater than the phenomenon of soil effective state content, through sample survey found that the atmospheric dust in the study area, surface water and groundwater exist different degree of heavy metal pollution phenomenon, crop seed heavy metals are derived from the possibility of atmospheric dust and water.