3.3. Soil enzymes activities
Soil enzyme activity has been proposed to be an important
determinant factor of soil quality. As the first enzyme to catalyze
the dehydrogenation of organic matter in electron transport
systems, dehydrogenase plays a key function in organic matter
degradation (Chaperon and Sauvé, 2007). DA is a useful indicator
of overall microbial activity of soils (Tam, 1998; Megharaj et al.,
1999). Hydrogen peroxide widely exists in the plant’s body and
soil, and has toxic action to biology and soil. Fungus, bacterium
and plant root in the soil can secrete catalase to relieve poisoning
effect of hydrogen peroxide (Wan et al., 2008). There were