4种农药对枇杷园土壤磷酸酶活性及微生物呼吸的影响

应用室内培养方法研究了甲基托布津、代森锰锌、杀灭菊酯、阿维菌素4种农药对枇杷园土壤磷酸酶活性及微生物呼吸的影响,并对4种农药进行了安全性评价。结果表明,经杀菌剂甲基托布津和代森锰锌处理的土壤,磷酸酶活性受到明显抑制,且抑制效果未见恢复。经杀灭菊酯和阿维菌素处理的土壤,磷酸酶活性变化呈现"抑制-恢复-激活"趋势;抑制作用随农药浓度的升高而增强;但7d后磷酸酶活性受到了一定程度的激活,35d达到最高值;高浓度杀灭菊酯和低浓度阿维菌素显示出较强的激活作用。农药对土壤微生物呼吸作用的影响初期表现为轻微激活,5d后出现抑制作用,12d后基本恢复正常,接近对照水平。通过安全性评价可知,供试4种农药对土壤微生物的危害较小,为无毒害或无实际危害的农药。

Effects of pesticides on soil phosphatase activity and respiration of soil microorganisms in loquat orchard

The effects of 4 pesticides(thiophanate-methyl,mancozeb,fenvalerate and abamectin)on soil phosphatase activity and respiration of soil microorganisms were investigated in this study.Safety levels of the four pesticides were also evaluated.Results show an irrecoverable inhibition of phosphatase activity in soils treated with thiophanate-methyl or mancozeb.Phosphatase activity of fenvalerate or abamectin treated soils are initially inhibited,but then reactivated after 7 days and hitting peak values 35 days after treatment.Reactivation gets stronger with higher concentration of fenvalerate and lower concentration of abamectin.Soil respiration is slightly stimulated during the initial period,inhibited after 5 days,and then recovers to control levels after 12 days.Safety evaluation shows that the four pesticides are slightly,but not practically,harmful to soil microorganisms due to their inherent toxicity.