Change of Enzyme Activity of Different Cropping Years in Greenhouse Soil

The paper studies change of enzyme activity with increasing cropping years in greenhouse soil. We furthermore took mancozeb, which was a fungicide commonly used in greenhouse soil in North China, as an example to study the change difference of greenhouse soil enzyme activity with different cropping years after addition of external agricultural chemical material. We found that with increasing cropping years of greenhouse soil, catalase activity decreased gradually, Sucrase activity presented the trend of “up-down-up”. Different cropping years of greenhouse soils showed different response to the external impact of mancozeb. Difference of enzyme activity in cropping years of greenhouse soil were insignificant after addition of 10 mg·kg
^-1
and 50 mg·kg
^-1
mancozeb. In this case, effect of mancozeb on the soil enzyme activity was insignificant. However, enzyme activities of catalase and sucrase in 10 years and 20 years greenhouse soils were all affected significantly after addition of 100 mg·kg
^-1
mancozeb. It suggested that resistance ability of greenhouse soil to the external impact became weaker with increasing cropping years, which should be paid our attention.