Impact of effective microorganisms on microbial communities and enzyme activities in rhizosphere soil of continuously cropped garlic

A pot experiment was conducted to study the effects of effective microorganisms (EM) on dry matter accumulation, microbial communities and enzyme activities in rhizosphere soil of continuously cropped garlic at different growth stages. The number of bacteria and fungi and the soil catalase activity initially increased and then decreased, and the maximum values were observed at the stem elongation stage. The maximum promotive effects of EM on sulfur bacteria and phenol-decomposing bacteria were observed at the bulb enlargement stage, and on ammonifying bacteria and nitrifying bacteria at the differentiation stage and seeding stage, respectively. The positive effect of EM on the quantity of actinomycetes and the activity of polyphenol oxidase, urease and phosphatase increased progressively and significantly with advancement of garlic growth. The soil microbial community structure, microbial populations, soil enzyme activities and dry matter accumulation were improved by use of EM.