除草剂莠去津对长期定位施肥土壤中酶活性的影响

Effects of Atrazine on Enzyme Activities in Soils with Long-term Fertilizer

研究了除草剂莠去津对4种长期定位施肥处理土壤中脲酶、磷酸酶、脱氢酶、蔗糖酶活性的影响．不同肥力处理的不施肥对照土壤、NPK肥土壤、NPK+秸秆和NPK+有机肥土壤中,4种酶受莠去津影响有明显差别．在莠去津处理初期,土壤中的脲酶活性受到不同程度地刺激作用,中期和后期土壤中的脲酶活性均受到抑制．其中NPK+有机肥土壤中的脲酶活性受到的抑制程度随着处理时间的延长而增加．在整个处理过程中NPK+秸秆土壤中的磷酸酶活性几乎不受莠去津抑制．其它3种土壤中的磷酸酶活性都不同程度地受到抑制,而且对照土壤受到的抑制程度最深．NPK土壤中的脱氢酶活性在处理初期受到刺激作用,中期和后期都受到抑制．其它3种土壤在处理初期和中期都受到抑制作用,但是后期抑制作用消失．NPK土壤和NPK+有机肥土壤中的蔗糖酶活性始终受到不同程度的激活,而且在处理后期激活作用加强．对照土壤中蔗糖酶受莠去津的影响较小,NPK+秸秆土壤中的蔗糖酶活性始终受到抑制作用．土壤中添加莠去津为5mg·kg-1时,处理16d的4种酶平均酶活性与不添加莠去津的土壤中平均酶活性没有显著差异．

The effects of atrazine on urease, phosphatase, dehydrogenase, and invertase in four soils fertilized in different ways were studied. The four enzyme activities were measured with normal methods during different time after the soils were treated by atrazine. The results showed that urease activities were no obvious changes at the first day, while inhibited in the middle and final time; in NPK＋S （Stalk）and NPK＋M （Manure）soils, the urease activities were stimulated at the first day, while inhibited in the middle time and the inhibition disappeared in the final time. Phosphatase activities were inhibited in CK soils at the first day, and the inhibition disappeared in the middle and final time; in NPK and NPK＋M soils, the phosphatase activities were inhibited, while stimulated in NPK＋S soils during the whole period. Dehydrogenase activities were inhibited in CK soils at the first day and in the middle time, but the inhibition disappeared in the final time; in NPK soils, dehydrogenase activities were stimulated at the first day, while inhibited in the middle and final time. Invertase activities in CK soils were stimulated at the first day, while inhibited in the middle time and the inhibition disappeared in the final time; invertase activities in NPK＋S and NPK＋M soils were stimulated and were inhibited in NPK soils during the whole period.The four soils were treated by atrazine with the concentration of 5mg ·kg^-1, but the average enzyme activities in the four soils were no significant difference during the whole time.