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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #405291

Research Project: Developing Resilient Irrigated Cropping Systems in Concentrated Dairy Production Areas of the Semi-arid West

Location: Northwest Irrigation and Soils Research

Title: Microbial responses to biochar soil amendment: A three-level meta-analysis

Author
item Dungan, Robert - Rob
item STRUHS, ETHAN - University Of Idaho
item MIRKOUEI, AMIN - University Of Idaho
item AHO, KEN - Idaho State University
item LOHSE, KATHLEEN - Idaho State University
item YOU, YAQI - State University Of New York (SUNY)
item KERNER, PATRICIA - Idaho State University

Submitted to: Environmental Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary: Biochar is a multi-functional soil conditioner capable of enhancing soil health and crop production while reducing greenhouse gas emissions. Understanding how soil microbes respond to biochar amendment is a vital step towards precision biochar application. Performing a meta-analyses on 3899 observations, we found that biochar significantly boosts microbial abundance and enzyme activities. Biochar characteristics, soil properties, and treatment protocols strongly determine the direction and extent of microbial response changes. Feedstock, pyrolysis temperature, application rate, and soil pH were most frequently identified as important model predictors. Our study highlights the promise of purpose-driven biochar production and application, such that biochar production parameters can be tuned to elicit the desired microbial responses.

Technical Abstract: Biochar is a multifunctional soil conditioner capable of enhancing soil health and crop production while reducing greenhouse gas emissions. Understanding how soil microbes respond to biochar amendment is a vital step towards precision biochar application. Here, we synthesized 3899 observations of 24 microbial responses from 61 primary studies, applied a three-level mixed-effects model to estimate biochar effects, and evaluated the importance of biochar characteristics (feedstock, pyrolysis temperature), soil properties (pH, C:N, cation exchange capacity, bulk or rhizosphere), and treatment protocols (application rate, fertilization, duration, field or laboratory). Biochar significantly boosts microbial abundance (microbial biomass carbon > CFU), nitrite reductase gene (nirS), the activity of C- and N-cycling enzymes (dehydrogenase > cellulase > urease > invertase), and potential nitrification rate. Biochar characteristics, soil properties, and treatment protocols strongly determine the direction and extent of microbial response changes. Feedstock, pyrolysis temperature, application rate, and soil pH are important predictors most frequently included in the final models. Our study highlights the promise of purpose-driven biochar production and application such that biochar production parameters can be tuned to elicit the desired microbial responses and application protocols could be optimized to invoke multiple benefits. It also underlines current knowledge gaps and future research needs.