Effect of natural weed and Siratro cover crop on soil fungal diversity in a banana cropping system in southwestern China

Yongfen Wang; Wenlong Zhang; Paul H Goodwin; Si-Jun Zheng; Xundong Li; Shengtao Xu

doi:10.3389/fmicb.2023.1138580

Effect of natural weed and Siratro cover crop on soil fungal diversity in a banana cropping system in southwestern China

Front Microbiol. 2023 Mar 22:14:1138580. doi: 10.3389/fmicb.2023.1138580. eCollection 2023.

Authors

Yongfen Wang¹, Wenlong Zhang², Paul H Goodwin³, Si-Jun Zheng^{2

4}, Xundong Li², Shengtao Xu²

Affiliations

¹ Institute of Tropical and Subtropical Cash Crops, Yunnan Academy of Agricultural Sciences, Baoshan, Yunnan, China.
² Yunnan Key Laboratory of Green Prevention and Control of Agricultural Transboundary Pests, Agricultural Environment and Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, China.
³ School of Environmental Sciences, University of Guelph, Guelph, ON, Canada.
⁴ Bioversity International, Kunming, Yunnan, China.

Abstract

Introduction: Natural weed cover and a legume cover crop were examined to determine if they could impact soil fungal diversity as an indicator of soil quality in banana production.

Methods: Banana in Yunnan Province, China, was grown under three treatments: conventional tillage (bare soil), natural weed cover (primarily goosegrass (Eleusine indica (L.) Gaerth)), or a cover crop (Siratro (Macroptilium atropurpureum (DC.) Urb.)). Analysis of the soil fungal communities between 2017 and 2020 was done by Illumina Miseq high-throughput sequencing.

Results: Most significant effects were in the intercropping area for the treatments, whereas it was rarely observed in the furrow planted with banana. Based on the Shannon and Simpson diversity indices, soil fungal diversity in the intercropping area significantly decreased following planting banana in 2017 with all three treatments. However, both the Shannon and Simpson diversity indices showed that there were significant increases in fungal soil diversity in 2019 and 2020 with natural weed cover or Siratro compared to bare soil. At the end of the experiment, significant increases in fungal genera with Siratro compared to bare soil were observed with Mortierella, Acremonium, Plectophaerella, Metarhizium and Acrocalymma, and significant decreases were observed with Fusicolla, Myrothecium, Exserohilum, Micropsalliota and Nigrospora. Siratro resulted in higher stability of the soil fungal microbiome by increasing the modularity and the proportion of negative co-occurrences compared to bare soil. For fungal guilds, Siratro significantly increased saprotrophs_symbiotrophs in 2019 and 2020 and significantly decreased pathogens_saprotrophs in 2020 compared to bare soil.

Discussion: Using Siratro as a cover crop in the intercropping area of banana helped maintain soil fungal diversity, which would be beneficial for soil health with more symbiotrophs and less pathogens in the soil. However, further research is needed to determine the long-term impact of weed or Siratro cover crop on the fungal soil ecosystem and growth of banana.

Keywords: banana; co-occurrence network; cover crop; soil fungal communities; soil microbial diversity.