Maize grown for bioenergy on peat emits twice as much carbon as when grown on mineral soil

A - Papers appearing in refereed journals

Lloyd, I. L., Morrison, R., Grayson, R. P., Cumming, A. M. J., D'Acunha, B., Galdos, M. V., Evans, C. D. and Chapman, P. J. 2024. Maize grown for bioenergy on peat emits twice as much carbon as when grown on mineral soil. Global Change Biology. Bioenergy. 16 (7), p. e13169. https://doi.org/10.1111/gcbb.13169

AuthorsLloyd, I. L., Morrison, R., Grayson, R. P., Cumming, A. M. J., D'Acunha, B., Galdos, M. V., Evans, C. D. and Chapman, P. J.
Abstract

The area of land dedicated to growing maize for bioenergy in the United Kingdom is rapidly expanding. To understand how maize production influences soil carbon (C) dynamics, and whether this is influenced by soil type, we measured net ecosystem exchange (NEE) using the eddy covariance technique over the 2021 growing season. We combined the NEE data with C imports and exports to calculate the net ecosystem productivity (NEP) of two maize crops grown for bioenergy in the United Kingdom, one site on mineral soil and the other on lowland agricultural peat. Maize was similarly productive at both sites—gross primary productivity was 1107 g C m−2 at the site with mineral soil and 1407 g C m−2 at the peat site. However, total ecosystem respiration was considerably higher from the peat site (1198 g C m−2) compared with the mineral soil site (678 g C m−2). After accounting for the removal of C in harvested biomass, both sites were net C sources, but C losses were over two times greater from the peat site (NEP = 290 g C m−2) than the mineral site (NEP = 136 g C m−2). While annual crops may be needed to produce bioenergy in the short term, growing maize for bioenergy in the United Kingdom does not appear to be a viable option for C sequestration over the long term, as it leads to high carbon losses from agroecosystems, especially those on organic soils. Instead, growing perennial bioenergy crops on mineral soils with a low organic C content is a more appropriate option.

KeywordsCarbon dioxide; Net ecosystem productivity; Eddy covariance; Greenhouse gas; Net ecosystem exchange
Year of Publication2024
JournalGlobal Change Biology. Bioenergy
Journal citation16 (7), p. e13169
Digital Object Identifier (DOI)https://doi.org/10.1111/gcbb.13169
Open accessPublished as ‘gold’ (paid) open access
FunderBiotechnology and Biological Sciences Research Council
Natural Environment Research Council
Funder project or codeGrowing Health [ISP]
Growing Health (WP2) - bio-inspired solutions for healthier agroecosystems: Understanding soil environments
Publisher's version
Output statusPublished
Publication dates
Online14 Jun 2024
ISSN1757-1707
PublisherWiley

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