Abstract:

Seasonal dynamic of catalase, phosphatase, urease, invertase activity of four black farmland areas with maize growth in Shuangcheng City in Heilongjiang Province was analyzed. The results showed that four enzyme activities differed during maize growth. Catalase activity increased firstly and then reduced steady, and finally increased, its peak appeared in the tasseling-silking stage. Phosphatase, urease activity increased at first, then decreased, its peak value was in the jointing stage. Invertase activity in maize growth period showed a downward trend, while enzyme activity was the highest in the seedling stage. Correlation analysis results indicated that there were no significant correlations between four enzyme activities and soil carbon nitrogen nutrient.