Effect of different fertilization practices on soil microbial activities and community structure in volcanic ash citrus orchard soil

摘要

This study was performed to evaluate effects of different fertilization practices on soil microbial activities and community structure using soil enzyme activities, PLFA contents in volcanic ash citrus orchard soil. Urease activity was high in NPK+Compost treatment, July. Dehydrogenase activity was higher in l/2NPK+Compost (4.3 mug TPF /g 24 /h) than other treatments in May. beta-glucosidase activity was higher in May than in September. That showed significant in between treatments and ordered NPK>1/2 NPK+Compost >NPK+Compost>Compost>3NPK>Control. Soil basal respiration rate decreased gradually and that was not different significantly between treatments. Total PLFA contents were higher in NPK+Compost than in compost. Distribution ratio of soil microbial groups by PLFA profiles as biomarker showed that bacteria and actinomycetes increased and both fungi and mycorrizae decreased in July relative to March. Principal component analysis of the microbial community by PLFA pattern showed that PLFA profiles from NPK and NPK+Compost plots were different at the 3NPK plot in March. Our result showed that composition change in microbial community were affected by a fertilization effect and seasonable factor.