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

Dungan, R.S. (2023) Microbial responses to biochar soil amendment: A three-level meta-analysis. Environmental Science and Technology. 57(48):19838-19848. 5 December 2023.

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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.

Item Type:	Article
NWISRL Publication Number:	1778
Subjects:	Air Quality > Air Emissions > Agricultural Soils Soil > Soil quality
Depositing User:	Users 11 not found.
Date Deposited:	25 Apr 2024 20:22
Last Modified:	25 Apr 2024 20:22
Item ID:	1821
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/1821