Impact Of Biochar Amendment On The Field Efficacy And Pesticide Residue And Bioavailability Of Pesticide

Biochar fixed carbon which in the wood, grass, corn stalk or other agicultural under the high-temperature and low oxygen environment. In recent years, many researchs of biochar have being deeply studied, including the impact on soil physical and chemical and soil ecosystem with biochar; the influence of adsorption of soil pollutants and organic pollutants of heavy metal ion; the mechanism of influence the global climate changing extremely by biochar.This paper mainly study on three aspects:1) impact of biochar amendment on the final residues of5%diazinon GR in Allium tuberosum and Brassica chinensi,2) impact of biochar Amendment on the Field Efficacy and the Residue of Diazinon GR in Peatnut Field,3) Impact of biochar amendment on the field efficacy and the residue of69%acetochlor·atrazine·2,4-D isooctyl ester SC in corn field.The results could be summarized as followings:1、Methods for determination of diazinon residue in chinese chive (Allium tuberosum), baby bokchoi (Brassica chinensi L), peanu t(Arachis hypogaea L.) and soil, and2,4-D isooctyl ester, acetochlor and atrazine in corn was estabished. The residues of diazinon,2,4-D isooctyl ester, acetochlor and atrazine were extracted by acetonitrile; then diazinon cleaned up by silicegel column,2,4-D isooctyl ester, acetochlor and atrazine by amino solid-phase extraction column, and determination by GC. The results showed that the recoveries of diazinon were88.7～109.6%, with highest RSD was6.52%, and the fortified levels of0.01～1.00mg/kg for the samples; and the recoveries of2,4-D isooctyl ester, acetochlor and atrazine were83.8～102.8%, and the fortified levels of0.01～1.00mg/kg. The minimum detectable of GC estimated for diazinon was0.01mg/kg and for2,4-D isooctyl ester, acetochlor and atrazine were0.01,0.01,0.05mg/kg respectively. The accuracy, reappearance and precision of the method well satisfied the essential rules of pesticide residue determination.2、Comparing with the control efficacy of5%diazinon GR for underground pests in peanut field, and the control efficacy of69%acetochlor-atrazine·2,4-D isooctyl ester SC for weeds in corn field with and without biochar. The results showed that biochar could improve the control efficacy of5%diazinon GR for underground pests and69%acetochlor·atrazine-2,4-D isooctyl ester SC for weeds but not significantly.3、The experiments were laid out under field conditions. Soil with biochar could extend the half-life, delay the degradation of pesticide and increase the pesticide residues in soils; shorten the half-life of pesticide in plants, reducing pesticide residues in plants; increased the final residues in soils and peanut shells, residue the final residues in the plant and corn grain. The half-life of diazinon, acetochlor and atrazine in soils extended to31.65d,17.24d and15.10d in soils, and it was0.61,1.08and1.77times than19.64d,8.27d and5.46d respectively. The shorter the half-life of pesticides, the more significant effects on pesticide half-life in soils with biochar. The half-life of acetochlor and atrazine in maize straw form18.89d and26.36d shortened to10.33d and18.94d, and it was reduced by45.82%and28.13%. The shorter the half-life of pesticides, the more significant effects on pesticide half-life in plants with biochar.4、Biochar could inhibit plants absorb and enrich pesticidue from soils significantly, reduce the bioavailability. The results prove that biochhar could inhibit chinese chive and baby bokchoi enrich diazinon. The biochar content in soils was higher, the more obviously inhibited chinese chive and baby bokchoi obsorbed diazinon. Relative to baby bokchoi, the inhibitory effect on chinese chive enriched diazinon was obvious. When applying pesticide concentration was0.025g/kg, the inhibitory effect on Chinese chive was the same to baby bokchoi by biochar content up to0.10%. When applying pesticide concentration was0.10g/kg, the inhibitory effect on Chinese chive was the same to baby bokchoi by biochar content up to1.00%.