Indigenously produced biochar retains fertility in sandy soil through unique microbial diversity sustenance: a step toward the circular economy

Munawwar Ali Khan; Alsayeda Zahra Salman; Shams Tabrez Khan

doi:10.3389/fmicb.2023.1158784

Indigenously produced biochar retains fertility in sandy soil through unique microbial diversity sustenance: a step toward the circular economy

Front Microbiol. 2023 Jun 27:14:1158784. doi: 10.3389/fmicb.2023.1158784. eCollection 2023.

Authors

Munawwar Ali Khan¹, Alsayeda Zahra Salman², Shams Tabrez Khan³

Affiliations

¹ Department of Life and Environmental Sciences, College of Natural and Health Sciences, Zayed University, Dubai, United Arab Emirates.
² Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea.
³ Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, Uttar Pradesh, India.

Abstract

Introduction: Agricultural productivity in the arid hot desert climate of UAE is limited by the unavailability of water, high temperature, and salt stresses. Growing enough food under abiotic stresses and decreasing reliance on imports in an era of global warming are a challenge. Biochar with high water and nutrient retention capacity and acid neutralization activity is an attractive soil conditioner. This study investigates the microbial community in the arid soil of Dubai under shade house conditions irrigated with saline water and the shift in the microbial community, following 1 year of amendment with indigenously prepared biochar from date palm waste.

Methods: Amplicon sequencing was used to elucidate changes in bacterial, archaeal, and fungal community structures in response to long-term biochar amendment. Samples were collected from quinoa fields receiving standard NPK doses and from fields receiving 20 and 30 tons ha^-1 of biochar, in addition to NPK for 1 year. Water holding capacity, pH, electrical conductivity, calcium, magnesium, chloride, potassium, sodium, phosphorus, total carbon, organic matter, and total nitrogen in the soil from biochar-treated and untreated controls were determined.

Results and discussion: The results show that soil amendment with biochar helps retain archaeal and bacterial diversity. Analysis of differentially abundant bacterial and fungal genera indicates enrichment of plant growth-promoting microorganisms. Interestingly, many of the abundant genera are known to tolerate salt stress, and some observed genera were of marine origin. Biochar application improved the mineral status and organic matter content of the soil. Various physicochemical properties of soil receiving 30 tons ha^-1 of biochar improved significantly over the control soil. This study strongly suggests that biochar helps retain soil fertility through the enrichment of plant growth-promoting microorganisms.

Keywords: arid soil; biochar; microbial community; plant growth promotion; salinity stress.

Grants and funding

This study was supported by Zayed University Research Incentive Grant (RIF-R21074) and Zayed University Provost Research Fellowship grant (R20096) awarded to MK.