Variation of Microbial Biomass and Enzyme Activities in the Rhizosphere Soil of Lily at Different Developmental Periods

The experiment was conducted to study the variation of the kinds and the number of microbial biomass and enzyme (catalase, urease, alkaline phosphatase) activities in the rhizosphere soil of different lily varieties at different developmental periods under nature conditions. The results showed that bacteria ranked first in the quantity of rhizosphere soil microorganism during the whole developmental periods and was the most sensitive to lily rhizosphere effect. Fungi was the second, and actinomycete was the third place. At flower budding period,the quantity of bacteria and actinomycete in the rhizosphere soil of lily appeared at most, but their rhizosphere effect was opposite after this period. The fungi quantity and its rhizosphere effect were great at bulb substantiating period. The activities of urease and alkaline phosphatase in the soil appeared in the trend of fall, rise and fall, and reached a peak at flower budding period with a remarkable rhizosphere effect, along with the reproductive development, the activities of the two enzymes and rhizosphere effect weakened gradually. The activity of catalase appeared in the trend of rise first and then fall,but the rhizosphere effect was not obvious. The results suggested that the microbial biomass and enzyme activities of rhizosphere soil are remarkably affected by the growth and development of lily in the interaction system of lily-soil-microorganisms.