The Research About The Relationship Between Heavy Metals Contamination And Crops On Farmland Soil In The Goldfield

Not only the continual development of economic but also health and survival of human being have been serious effected by environment pollution. In order to study the relationships between soil contamination and human food chain,46 soil samples and 18 crops samples were generally and systemically collected from the researching area 100 km2 of farmland cultivating layers. Seven kinds of heavy metals named hydrargyrum, plumbum, cadmium, arsenic, chromium, copper, zinc were evaluated and analyzed in character content, distributing in space, index of polluting and synthesized index of polluting. It is the first analysis in the study area that we use the soil chemical speciation analyzing the relationship of soil-plant system. And the relation is the emphases in the thesis. The results show that:(1) Hydrargyrum and lead are the most important pollution elements in the soil. the hydrargyrum sample standard rate reached 69.60 percent, and lead exceeded rate of 34.8%. Excessive accumulation of multiple results indicate that seven heavy metals'single accumulation times index in the soil exceed the rate of 70%, of which mercury, lead, cadmium, chromium, copper and zinc exceeded more than 90%; According to the analyzing of synthetic pollution index,58% of soil samples is contaminative. The area of contaminated soil is 95.95km2, which is the 95.95% of the total area. According to the analyzing of synthetic accumulation index,100% of soil samples is contaminative.(2) Hydrargyrum and lead are the most important pollution elements in the crops. The single pollution times index of corn hydrargyrum is 4.45, which is the highest, while wheat lead contamination exceeded the highest rate of 100%. Cadmium, chromium and arsenic are the secondary pollutants in the crops. Copper and zinc are nutritious elements, whose pollution in the wheat and corn are not serious.(3)There is highly significant positive correlation (p<0.01) between soil hydrargyrum, lead, cadmium, copper and zinc in various forms and the total. It shows that the content of heavy metals in soil in the soil has a large extent impact on the content of various forms; There is a rule:heavy metals in soil total> Soils content> heavy metals in plants, which shows that heavy metals in plants and soil heavy metals may show a certain degree of positive correlation. (4)There was a direct radio relationship between heavy metals exceeding standard in wheat and corn and soil pollution. The correlational coefficient of heavy metals content in crops and soil showed that cadmium only had the visible relativity, but the content of remanent heavy metals in crops and soil didn't have the visible relativity. The results showed that content of heavy metals of crops adsorbed from atmosphere in this soil pollution area.