Study On Mercury Accumulation In Grape Plants Of Soil

Mercury pollution is one of the serious environment issues in the world. It is endangering soil-crop systems and harms health of human being through food chains.The mobility and bioavailability of mercury depend on its speciation in soil.The species of mercury in soil controlled by general soil characteristies and other factors. With field survey in grapevine growing area in Huailai-Zhuolu basin, and pot experiment, investigation was made mainly on speciation of mercury in soil-crop and its influencing factors.Conclusions can be drawn as follows:1. With field survey in grapevine growing area in Huailai-Zhuolu basin ,MapGis,ArcGis,geostatistic Kriging interpolation and correlation analysis were applied to analyze the spatial variability of soil mercury contents. Soil geochemistry of mercury contents、soil physical-chemical properties and grape mercury contents in Huailai-Zhuolu basin were studied. The results showed that :Soil mercury distribution was identified as an exponential model by fitting the semivariance model. It has obvious correlation with spatial variations. we also analyzed the contributing factors on soil mercury contents. Organic fertilizer physical clay are important factors which influence the spatial variability of soil mercury contents. Based on analysis of mercury speciation in potting soil the grape, concentration of different mercury species in potting soil is as follows: residue-bound and organic substance-bound which is hard to be oxidized and degraded were most. With cultivation times ,the the available mercury species in soil decreased, residue-bound and organic substance-bound which is hard to be oxidized and degraded increased. However, with that no planting , planting,it indicates that during the growth of grape, the available mercury species in soil increased, and stable species decreased.With organic fertilizer mercury speciation transforms obviously from available mercury to residue-bound, potentially available mercury.2. With the increase of soil mercury concentrations, every forms of mercury content have increased; In the sprout period, Hg the main morphology of soil was available mercury. and other growth period mainly in stable state Hg primarily. With the growth the passage of time, the soil, effective state Hg content decrease, residual organic matter degradation and difficult to oxidation state combination state content increased. compared with without organic fertilizer, organic combination state of humic acid Hg significantly increased, but effective state is decreased obviously.3. With the inerease of Hg content in soil,The length of 1-5 leaves of grape and the diameter of the branch were decreaced, It showed that Hg obviously inhibited length and strength growth. With Hg stress in soil pollution, organic fertilizer inhibited the growth of branches significantly,It explained that the inhibition of Hg stress promoting effect than organic fertilizer.With the inerease of Hg content and cultivation times, cell membrane permeability, pro1ine contents and MDA contents all increased.And aetivity of antioxidant enzyme include SOD,POD and CAT activities,when low concentrations of Hg,they can resistance. While high concentrations of Hg inhibited their aetivities.These results indicated that lower concentration of Hg,can increase the endurances of grape plants in short term.But with the higher concentration and extension of time this effect will decrease,.even inhibited to grow. With the inerease of Hg content in soil, berry weight、Vc and total sugar were reduced,but it was not significant. In the contrary,fruit acidity was significant increased.4. concentration of mercury in grape is as follows in sequence: fruit<flower<branch<leaf. When mercury in the soil add to 1.5 mg/kg, The content of Hg element in grape far below than state regulations limit of mercury in food hygiene standards.But When mercury in the soil add to 25 mg/kg, The content of Hg element in grape more than state regulations limit of mercury in food hygiene. the mercury content of grape branches and leaves was highest in young fruit growth period. In the low concentration Hg pollution.The change of Hg content in vine branches and leaves with the the growth time of grape,was same with the change of available and residue mercury. As with any other form changes the change tendency of the present instead. In high concentration Hg pollution, in young fruit growth period, though the content of humic acid effective and complexation mercury of soil is low, vine branches, leaves Hg content is still at the highest. Maybe in the young fruit growth period, available mercury content is higher.In addition, maybe because of grape rapid growth and promote its to the absorption of mercury has the very big relations.Organic fertilizer of soil reduced available mercury in soil, and then reduce the mercury content of grape branches, leaves,then the Poison reduced.5. Mercury pollution insoil restrain soil catalase invertase and urease activity, Low concentration of mercury to have certain activation of alkaline phosphatase , and high levels of mercury can inhibit the activity, but with the passage of time, the inhibition gradually ease.Organic fertilizer on enhancing the soil catalase, alkaline phosphatase and urease activity but will prevent soil invertase activity. 6. Based on its high economic value and low accumulation to Hg (≦2mg/kg) ,grapes has considerable potential for application instead of Hg pollution sensitive food crops or vegetables, to construct a new production and operation mode.