Functional diversity of rhizosphere soil microbial communities in response to different tillage and crop residue retention in a double-cropping rice field.

Haiming Tang,Li Wen,Ke Wang,Kaikai Cheng,Xiaoping Xiao,Chao Li,Xiaochen Pan,Lihong Shi,Wenguang Tang,Weiyan Li,Jian Liu

doi:10.1371/journal.pone.0233642

Abstract

Microbial community functional diversity is a sensitive indicator of soil quality, soil management such as tillage and crop residue which can affect the microbial community functional diversity of paddy field. However, there is still limited information about the influence of different tillage and crop residue management on rhizosphere soil microbial community functional diversity in a double-cropping rice (Oryza sativa L.) field. Therefore, four tillage treatments were set up in paddy field, tillage treatments were included: conventional tillage with residue incorporation (CT), rotary tillage with residue incorporation (RT), no-tillage with residue retention (NT), and rotary tillage with residue removed as control (RTO). And the effects of CT, RT, NT, and RTO treatments on the average well color development (AWCD), genetic diversity indices and carbon source utilization of rhizosphere soil were studied in the present paper. The results showed that the values of AWCD with CT, RT and NT treatments were higher than that of RTO treatment. It was implied that application of crop residue management resulted in the variation of the carbon utilization efficiency of rhizosphere soil microbial communities. At maturity stages of early and late rice, the Richness indices, Shannon indices and McIntosh indices with CT treatment were significantly higher than that of RTO treatment, and with the order as CT>RT>NT>RTO. Principal component analysis (PCA) results indicated that there were significant differences in carbon substrate utilization patterns among different tillage treatments. Carbohydrates and amino acids were the main carbon resources utilized by rhizosphere soil microbes. Therefore, the combined application of tillage with crop residue management could significantly increase the rhizosphere soil microbial community functional diversity in the double-cropping paddy field of southern China.

Highlights

In recent years, the traditional practice of intensive cultivation involving several deep ploughing and complete removal of crop residue have resulted in low organic matter content, low fertility and high susceptibility to erosion in soils
The results indicated that value of average well color development (AWCD) were rapid increased until 120 h with CT, residue incorporation (RT) and no-tillage with residue retention (NT) treatments, and the AWCD were ended at 120 h with removed as control (RTO) treatment (Fig 1)
The results indicated that value of AWCD with CT, RT and NT treatments were higher (p

Summary

Introduction

The traditional practice of intensive cultivation involving several deep ploughing and complete removal of crop residue have resulted in low organic matter content, low fertility and high susceptibility to erosion in soils. Some studies indicated that conservation agriculture has been found to increase crop yield, improve water use efficiency, reduce energy inputs, and improve soil fertility [1,2]. The soil microbial community was closely related to the agricultural practices, such as crop residue, organic input, and tillage management, and so on [11]. Wang et al [14] results found that diversity and stability of soil microbial community were increased with long-term no-tillage and organic input management. Sirisha et al [1] results found that soil microbial community were increased under combined application of crop residue with conservation tillage conditions. Other studies found that both soil microorganism metabolic activity, Shannon index and Simpson index were increased with no-tillage and residue retention management [7, 16]

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Discussion

Conclusion