Biochar-based fertilizer: Supercharging root membrane potential and biomass yield of rice

Jinkiat Chew, Longlong Zhu, Shaun Nielsen, Ellen Graber, David R.G. Mitchell, Joseph Horvat, Mohanad Mohammed, Minglong Liu, Lukas van Zwieten, Scott Donne, Paul Munroe, Sarasadat Taherymoosavi, Ben Pace, Aditya Rawal, James Hook, Chris Marjo, Donald S. Thomas, Genxing Pan, Lianqing Li, Rongjun Bian & 7 others Anna McBeath, Michael Bird, Torsten Thomas, Olivier Husson, Zakaria Solaiman, Stephen Joseph, Xiaorong Fan

Research output: Contribution to journalArticle

Abstract

Biochar-based compound fertilizers (BCF) and amendments have proven to enhance crop yields and modify soil properties (pH, nutrients, organic matter, structure etc.) and are now in commercial production in China. While there is a good understanding of the changes in soil properties following biochar addition, the interactions within the rhizosphere remain largely unstudied, with benefits to yield observed beyond the changes in soil properties alone. We investigated the rhizosphere interactions following the addition of an activated wheat straw BCF at an application rates of 0.25% (g·g 1 soil), which could potentially explain the increase of plant biomass (by 67%), herbage N (by 40%) and P (by 46%) uptake in the rice plants grown in the BCF-treated soil, compared to the rice plants grown in the soil with conventional fertilizer alone. Examination of the roots revealed that micron and submicron-sized biochar were embedded in the plaque layer. BCF increased soil Eh by 85 mV and increased the potential difference between the rhizosphere soil and the root membrane by 65 mV. This increased potential difference lowered the free energy required for root nutrient accumulation, potentially explaining greater plant nutrient content and biomass. We also demonstrate an increased abundance of plant-growth promoting bacteria and fungi in the rhizosphere. We suggest that the redox properties of the biochar cause major changes in electron status of rhizosphere soils that drive the observed agronomic benefits.

Original languageEnglish
Article number136431
JournalScience of the Total Environment
Volume713
DOIs
Publication statusPublished - 15 Apr 2020

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Chew, J., Zhu, L., Nielsen, S., Graber, E., Mitchell, D. R. G., Horvat, J., ... Fan, X. (2020). Biochar-based fertilizer: Supercharging root membrane potential and biomass yield of rice. Science of the Total Environment, 713, [136431]. https://doi.org/10.1016/j.scitotenv.2019.136431