Minimum tillage and residue retention increase soil microbial population size and diversity: Implications for conservation tillage

Yuan Li; Qingping Zhang; Yanjiang Cai; Qian Yang; Scott X Chang

doi:10.1016/j.scitotenv.2020.137164

Minimum tillage and residue retention increase soil microbial population size and diversity: Implications for conservation tillage

Sci Total Environ. 2020 May 10:716:137164. doi: 10.1016/j.scitotenv.2020.137164. Epub 2020 Feb 6.

Authors

Yuan Li¹, Qingping Zhang², Yanjiang Cai³, Qian Yang⁴, Scott X Chang⁵

Affiliations

¹ The State Key Laboratory of Grassland Agro-ecosystems, Lanzhou University, College of Pastoral Agriculture Science and Technology, Lanzhou 730020, China; Department of Soil and Physical Sciences, Lincoln University, Lincoln 7647, New Zealand; Manaaki Whenua - Landcare Research, Lincoln 7640, New Zealand.
² The State Key Laboratory of Grassland Agro-ecosystems, Lanzhou University, College of Pastoral Agriculture Science and Technology, Lanzhou 730020, China.
³ State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China.
⁴ The State Key Laboratory of Grassland Agro-ecosystems, Lanzhou University, College of Pastoral Agriculture Science and Technology, Lanzhou 730020, China. Electronic address: yangqian08@lzu.edu.cn.
⁵ State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China; Department of Renewable Resources, University of Alberta, Edmonton, Alberta T6G 2E3, Canada. Electronic address: scott.chang@ualberta.ca.

PMID: 32059331
DOI: 10.1016/j.scitotenv.2020.137164

Abstract

A global meta-analysis was conducted to evaluate the effect of conservation tillage practices on soil microbial population size [based on microbial count and phospholipid fatty acid (PLFA) measurements], diversity (Shannon index), and microbial community structure. Both no-tillage (NT) and NT plus residue retention (NTS) increased soil microbial count as compared with conventional tillage (CT). Bacteria, fungi, and actinomycete counts were 3%, 18%, and 28%, respectively, higher under the NTS treatment relative to the NT treatment, and 38%, 41%, and 28%, respectively, higher in the CT plus residue retention (CTS) treatment than in the CT treatment. No-tillage, as compared to CT, increased total PLFAs by 11%. The concentration of fungal PLFAs was increased by 17% by NT as compared to CT, but was decreased by 52% by NTS as compared to NT. The actinomycete PLFA concentration was decreased by reduced tillage and CTS, compared to CT. Compared with CT, NT increased the Shannon index of the total microbial and bacterial communities by 4% and 6%, respectively. The bacterial count was negatively associated with mean annual precipitation (275-1624 mm) and experimental duration (1-35 years) and positively associated with initial total soil nitrogen concentration. Overall, relative to CT, minimum tillage alone increased soil microbial count, fungal biomass, and bacterial diversity; residue retention alone increased soil microbial count and fungal diversity, and decreased the biomass of actinomycetes; combining minimum tillage and residue retention increased soil microbial count and fungal diversity. We conclude that the response to minimum tillage and residue retention was consistently positive for soil microbial count but was context dependent for microbial biomass, diversity, and community structure.

Keywords: Conservation agriculture; Microbial count; Microbial diversity; PLFA; Soil property.

Publication types

Meta-Analysis

MeSH terms

Agriculture
Fungi
Soil Microbiology*
Soil*

Substances

Soil