The Effects Of Two Herbicides On Crop And Remediation Of Biochar

Fomesafen and imazethapyr were common herbicides used on soybeans and peanuts. Aim at theproblem of the residual in the soil, a method was developed for the determination of the fomesafen andimazethapyr residue soil. Effect of two kinds of long residual herbicide on physiology and biochemistry ofthe crop and succeeding crop were studied, as well as the influence of the biochar on reducing injury ofherbicide. Specific results are as follows:(1)The fomesafen residue in soil sample was vortex extracted by acetonitrile and purified by PSA, andthan analyzed by using high performance liquid chromatography. The imazethapyr residue in soil samplewas vortex extracted by methanol and analyzed by using high performance liquid chromatography after theextract by acidification. The results of experiment showed that the chromatographic conditions offomesafen and imazethapyr were critically optimized and the results showed good linearity in the rangesfrom0.05to10.0mg/L. The regression equation was y=2.5628x-0.0068（R2=0.9998）and y=4.0038x-0.2756（R2=0.9995）. The average recoveries of fomesafen in soil were85%~99.7%and the relativestandard deviations were2.3%~6.9%at spiking levels of0.05mg/kg～0.5mg/kg. The average recoveriesof imazethapyr in soil were93.9%~104.3%and the relative standard deviations were2.9%~7.4%at spikinglevels of0.05mg/kg～1.0mg/kg. Limit of quantification of fomesafen and imazethapyr in soil were0.029mg/kg and0.021mg/kg. The methods were simple, economic, efficient and sensitive, and it is suitable forthe determination of fomesafen and imazethapyr residues in soil.(2) Different concentrations of fomesafen and imazethapyr residues both have stress effect on growthof wheat and rapeseed, and with the increase of the residual the stress became obvious. The two herbicidesresidues in the field inhibit plant height, and have influence of antioxidant enzymes in leaves: the activity of SOD and CAT were decreased, the activity of POD was increased. At the same time the two herbicidesresidues reduce the content of chlorophyll and increase the content of MDA in the lamina. Compared withthe two succeeding crops, rapeseed is more sensitive than wheat. The suppression of rapeseed degreeincreased and the rapeseed plants all died since the fourth sampling at some high concentrations offomesafen and imazethapyr.(3) Different concentrations of fomesafen and imazethapyr residues both have stress effect on growthof peanut and soybean. The two herbicides residues in the field inhibit plant height, and have influence ofantioxidant enzymes in leaves: the activity of SOD and CAT were decreased, the activity of POD wasincreased. At the same time the two herbicides residues reduce the content of chlorophyll and increase thecontent of MDA in the lamina. It is investigated that different concentrations of biochar reduce theherbicide stress in peanut and soybean, and with the increasing of additive amount, stress gradually reduce.As the biochar additive got8g/kg, the inhibition on peanut under quadruple recommended amount offomesafen could be remediationd, and2g/kg of biochar additive could remediation the inhibition onsoybean under eightfold recommended amount of fomesafen. As the biochar additive got16g/kg, theinhibition on peanut under double recommended amount of imazethapyr could be remediationd, and2g/kgof biochar additive could remediation the inhibition on soybean under eightfold recommended amount ofimazethapyr.(4) The residue of fomesafen in the field inhibit height of wheat, and have influence of antioxidantenzymes in wheat leaves: the activity of SOD and CAT were decreased, the activity of POD was increased.At the same time the fomesafen residues reduce the content of chlorophyll and increase the content ofMDA. Fomesafen inhibits the activity of protoporphyrinogen oxidase in wheat leaves, and imazethapyrinhibits the activity of acetolactate synthase in wheat leaves. It is investigated that different concentrations of biochar reduce the herbicide stress in wheat, and with the increasing of additive amount, stress graduallyreduce. As the biochar additive got4g/kg, the inhibition on wheat under double recommended amount offomesafen could be remediationd, and16g/kg of biochar additive could remediation the inhibition onwheat under triple recommended amount of fomesafen.