Open AccessSubstantial carbon loss respired from a corn–soybean agroecosystem highlights the importance of careful management as we adapt to changing climate
Author(s) -
Caitlin E. Moore,
Christy Gibson,
Guofang Miao,
Evan Dracup,
Nuria GomezCasanovas,
Michael D. Masters,
Jesse Miller,
Adam C. von Haden,
Tilden P. Meyers,
Evan H. DeLucia,
Carl J. Bernacchi
Publication year - 2022
Publication title -
environmental research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.37
H-Index - 124
ISSN - 1748-9326
DOI - 10.1088/1748-9326/ac661a
Subject(s) - agroecosystem , ecosystem respiration , environmental science , eddy covariance , growing season , ecosystem , primary production , agronomy , climate change , carbon cycle , zoology , ecology , biology , agriculture
Understanding agroecosystem carbon (C) cycle response to climate change and management is vital for maintaining their long-term C storage. We demonstrate this importance through an in-depth examination of a ten-year eddy covariance dataset from a corn–corn–soybean crop rotation grown in the Midwest United States. Ten-year average annual net ecosystem exchange (NEE) showed a net C sink of −0.39 Mg C ha −1 yr −1 . However, NEE in 2014 and 2015 from the corn ecosystem was 3.58 and 2.56 Mg C ha −1 yr −1 , respectively. Most C loss occurred during the growing season, when photosynthesis should dominate and C fluxes should reflect a net ecosystem gain. Partitioning NEE into gross primary productivity (GPP) and ecosystem respiration (ER) showed this C ‘burp’ was driven by higher ER, with a 51% (2014) and 57% (2015) increase from the ten-year average (15.84 Mg C ha −1 yr −1 ). GPP was also higher than average (16.24 Mg C ha −1 yr −1 ) by 25% (2014) and 37% (2015), but this was not enough to offset the C emitted from ER. This increased ER was likely driven by enhanced soil microbial respiration associated with ideal growing season climate, substrate availability, nutrient additions, and a potential legacy effect from drought.