Functional and structural responses of bacterial a

Authors: Yalong Liu Ping Wang Genxing Pan David Crowley Lianqing Li Jinwei Zheng Xuhui Zhang Jufeng Zheng

Publish Date: 2015/12/30

Volume: 16, Issue: 5, Pages: 1460-1471

PDF Link

Abstract

Rice paddy soils undergo pedogenesis driven by periodic flooding and drainage cycles that lead to accumulation of organic matter and the stratification of nutrients and oxygen in the soil profile Here we examined the effects of continuous rice cultivation on microbial community structures enzyme activities and chemical properties for paddy soils along a chronosequence representing 0–700 years of rice cropping in ChinaChanges in the abundance and composition of bacterial and fungal communities were characterized at three depths 0–5 5–10 and 10–20 cm in relation to organic carbon total nitrogen dissolved organic carbon microbial biomass carbon/nitrogen and activities of acid phosphatase invertase and ureaseBoth soil organic carbon and total nitrogen increased over time at all three depths while pH generally decreased Microbial abundance bacteria and fungi and invertase and urease activity significantly increased with the duration of rice cultivation especially in the surface layer Fungal abundance and acid phosphatase activity declined with depth whereas bacterial abundance was highest at the 5–10cm soil depth Profiles of the microbial community based on PCRDGGE of 16S rRNA indicated that the composition of fungal communities was strongly influenced by soil depth whereas soil bacterial community structures were similar throughout the profileSoil bioactivity microbial abundance and soil enzymes gradually increased with organic carbon and total nitrogen accumulation under prolonged rice cultivation Microbial activity decreased with depth and soil microbial communities were stratified with soil depth The fungal community was more sensitive than the bacterial community to cultivation age and soil depth However the mechanism of fungal community succession with rice cultivation needs further research

Keywords: