Environmental Effects Of Heavy Metal Contamination In The Soil - Wheat, Sorghum System Of Organic Manure

This research has been did under the environment of GuiZhou karst special landform, the object of experiment is the winter wheat and sorghum,The winter wheat and sorghum were studied by the pot and field experiment.We have researched the influence of winter wheat and Sorghum rhizosphere soil Pb,Hg,Ni and Cd shape transformation and plant validity.Main conclusions are as follows:(1) Applying increase the content of Organic matter,total nitrogen,total pH and total potassium organic fertilizer,and the pH value of soil to assume the weak basicity.(2) In the wheat field/pot experiments,The analytic result indicated that the contents of total Hg,Cd,Ni,Pb and available Hg,Cd,Ni,Pb in soils were increased with increasing amount of Hg,Cd,Ni,Pb added,so that the content of Hg,Cd,Ni,Pb in winter wheat was increased.Relationships between contents of available Hg,Cd,Ni,Pb in soils and contents of Hg,Cd,Ni,Pb in roots,stems/leaves and seeds of wheat were significant positivly correlated respectively.(3) In the wheat field/pot experiments,The available Hg,Cd,Ni,Pb in soils were obvious Influenced by the organic fertilizer.The restraining effect of applied organic fertilizer for contents of available Hg,Cd,Ni,Pb in soils is that treatment of higher organic fertilizer with lower Hg,Cd,Ni,Pb is best.(4) In the wheat field/pot experiments,Relationships between amount of applied organic fertilizer and contents of Hg,Cd,Ni,Pb in wheat root and stem/leaf under lower Hg,Cd,Ni, Pb level in seeding period are negative correlated significantly,but Relationships between amount of applied organic fertilizer and contents of Hg,Cd,Ni,Pb in wheat root,stem/leaf and seed under all Hg,Cd,Ni,Pb levels in harvesting period are significant negative correlated respectively..(5) in the sorghum pot experiments,The analytic result indicated that the contents of total Hg,Cd,Pb and available Hg,Cd,Pb in soils were increased with increasing amount of Hg,Cd,Pb added,so that the content of Hg,Cd,Pb in sorghum was increased. Relationships between contents of available Hg,Cd,Pb in soils and contents of Hg,Cd,Pb in roots,stems/leaves and seeds of sorghum were significant positivly correlated respectively.(6) In the sorghum pot experiments,The available Hg,Cd,Pb in soils were obvious Influenced by the organic fertilizer.The restraining effect of applied organic fertilizer for contents of available Hg,Cd,Pb in soils is that treatment of higher organic fertilizer with lower Hg,Cd,Pb is best too.(7) In the sorghum pot experiments,Relationships between amount of applied organic fertilizer and contents of Hg,Cd,Pb in sorghum root and stem/leaf under lower Hg,Cd,Pb level in seeding period are significant negative correlated respectively,but Relationships between amount of applied organic fertilizer and contents of Hg,Cd,Pb in sorghum root, stern/leaf and seed under all Hg,Cd,Pb levels in harvesting period are significant negative correlated respectively.(8) The distribution regular of contents of Hg,Cd,Ni,Pb in wheat organs is that root＞stem/leaf＞seed.;The distribution regular of contents of Hg,Cd,Pb in sorghum a organs is root＞stem/leaf＞seed.(9) In pot's experiment of wheat:the best level of organic fertilizer for reduce the Hg,Cd, Ni,Pb of wheat is F2(40g/kg),F3(67g/kg);In field's experiment of wheat:the best level of organic fertilizer for reduce the Hg,Cd,Ni,Pb of wheat is D(0.45kg/m~2) and E (0.53kg/m~2);In pot's experiment of sorghum:the best level of organic fertilizer for reduce the Hg,Cd,Ni,Pb of sorghum is F2(13g/kg).(10) The result of Environmental evaluation indicated that the soil of wheat,sorghum planter area of Guizhou has not been polluted,but the Pb already reached the Warning level; The Cd,Hg,Pb,and Ni are all below the food safety level.Therefore we knows the heavy metal content in soil of wheat,sorghum planting area is low,the environmental quality of soil is good in wheat and sorghum planter area of Guizhou.