Long-term straw return to a wheat-maize system results in topsoil organic C saturation and increased yields while no stimulating or reducing yield-scaled N2O and NO emissions

Zhisheng Yao; Yanqiang Wang; Rui Wang; Xiaogang Wang; Yan Wang; Xunhua Zheng; Chunyan Liu; Bo Zhu; Minghua Zhou; Yan Liu; Klaus Butterbach-Bahl

doi:10.1016/j.agrformet.2024.109937

Long-term straw return to a wheat-maize system results in topsoil organic C saturation and increased yields while no stimulating or reducing yield-scaled N₂O and NO emissions

Zhisheng Yao^*, Yanqiang Wang, Rui Wang, Xiaogang Wang, Yan Wang, Xunhua Zheng, Chunyan Liu, Bo Zhu, Minghua Zhou, Yan Liu, Klaus Butterbach-Bahl

^*Corresponding author af dette arbejde

Institut for Bio- og Kemiteknologi - Environmental Engineering - Gustav Wieds Vej 10D
Institut for Agroøkologi - Center for Landscape Research in Sustainable Agricultural Futures - Land-CRAFT

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avis › Tidsskriftartikel › Forskning › peer review

3 Citationer (Scopus)

Abstract

Straw return to agricultural soils is considered as a key strategy to improve soil organic C (SOC) sequestration and crop production. However, changes in SOC can affect soil N-turnover and associated N₂O and NO fluxes, as soil biogeochemical C- and N-cycles are strongly coupled. Understanding how and to what extent N-trace gas emissions per unit crop yield respond to changes in SOC following straw return, is critical for balancing food security and climate change mitigation. Here we report on an experiment in a Chinese wheat-maize system designed to understand the effects of long-term (2005–2020) different straw management options (straw return, burning or removal) on SOC stocks and yields, completed by N₂O and NO flux measurements over the period 2016–2020. Our results showed that the increase in SOC stocks following straw return tended to level off over time, indicating that SOC saturation is reached after 12–13 years under straw return. Soil N-trace gas emissions showed high inter- and intra-annual variability, which were largely driven by changes in rainfall, soil hydrothermal conditions or soil C- and N-availability. Compared to straw burning or removal, long-term straw return increased annual N₂O emissions by 9 %-49 %, to 2.72–2.98 kg N ha⁻¹ yr⁻¹, while NO emissions were decreased by 12 %-28 %, to 0.83–0.90 kg N ha⁻¹ yr⁻¹. The annual N₂O emissions roughly offset the total C sink (SOC sequestration and CH₄ uptake) by 40 %-46 %, but will override the climate benefits of total C sink as the SOC pool becomes saturated. However, because yields were higher in straw return treatments, yield-scaled annual N₂O emissions remained unchanged. Our unique dataset allows for the first time a better understanding of the dynamics between SOC sequestration, yields and N-trace gas emissions, with results calling for action to address the risk of increasing N₂O emissions following long-term SOC increases induced by straw return.

Originalsprog	Engelsk
Artikelnummer	109937
Tidsskrift	Agricultural and Forest Meteorology
Vol/bind	349
Antal sider	16
ISSN	0168-1923
DOI	https://doi.org/10.1016/j.agrformet.2024.109937
Status	Udgivet - apr. 2024

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Citationsformater

Yao, Z., Wang, Y., Wang, R., Wang, X., Wang, Y., Zheng, X., Liu, C., Zhu, B., Zhou, M., Liu, Y., & Butterbach-Bahl, K. (2024). Long-term straw return to a wheat-maize system results in topsoil organic C saturation and increased yields while no stimulating or reducing yield-scaled N₂O and NO emissions. Agricultural and Forest Meteorology, 349, Artikel 109937. https://doi.org/10.1016/j.agrformet.2024.109937

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title = "Long-term straw return to a wheat-maize system results in topsoil organic C saturation and increased yields while no stimulating or reducing yield-scaled N2O and NO emissions",

abstract = "Straw return to agricultural soils is considered as a key strategy to improve soil organic C (SOC) sequestration and crop production. However, changes in SOC can affect soil N-turnover and associated N2O and NO fluxes, as soil biogeochemical C- and N-cycles are strongly coupled. Understanding how and to what extent N-trace gas emissions per unit crop yield respond to changes in SOC following straw return, is critical for balancing food security and climate change mitigation. Here we report on an experiment in a Chinese wheat-maize system designed to understand the effects of long-term (2005–2020) different straw management options (straw return, burning or removal) on SOC stocks and yields, completed by N2O and NO flux measurements over the period 2016–2020. Our results showed that the increase in SOC stocks following straw return tended to level off over time, indicating that SOC saturation is reached after 12–13 years under straw return. Soil N-trace gas emissions showed high inter- and intra-annual variability, which were largely driven by changes in rainfall, soil hydrothermal conditions or soil C- and N-availability. Compared to straw burning or removal, long-term straw return increased annual N2O emissions by 9 %-49 %, to 2.72–2.98 kg N ha−1 yr−1, while NO emissions were decreased by 12 %-28 %, to 0.83–0.90 kg N ha−1 yr−1. The annual N2O emissions roughly offset the total C sink (SOC sequestration and CH4 uptake) by 40 %-46 %, but will override the climate benefits of total C sink as the SOC pool becomes saturated. However, because yields were higher in straw return treatments, yield-scaled annual N2O emissions remained unchanged. Our unique dataset allows for the first time a better understanding of the dynamics between SOC sequestration, yields and N-trace gas emissions, with results calling for action to address the risk of increasing N2O emissions following long-term SOC increases induced by straw return.",

keywords = "Carbon saturation, Cropland, Emission factor, Nitric oxide, Nitrous oxide, Soil carbon sequestration, Straw return",

author = "Zhisheng Yao and Yanqiang Wang and Rui Wang and Xiaogang Wang and Yan Wang and Xunhua Zheng and Chunyan Liu and Bo Zhu and Minghua Zhou and Yan Liu and Klaus Butterbach-Bahl",

note = "Publisher Copyright: {\textcopyright} 2024 Elsevier B.V.",

year = "2024",

month = apr,

doi = "10.1016/j.agrformet.2024.109937",

language = "English",

volume = "349",

journal = "Agricultural and Forest Meteorology",

issn = "0168-1923",

publisher = "Elsevier B.V.",

}

Yao, Z, Wang, Y, Wang, R, Wang, X, Wang, Y, Zheng, X, Liu, C, Zhu, B, Zhou, M, Liu, Y & Butterbach-Bahl, K 2024, 'Long-term straw return to a wheat-maize system results in topsoil organic C saturation and increased yields while no stimulating or reducing yield-scaled N₂O and NO emissions', Agricultural and Forest Meteorology, bind 349, 109937. https://doi.org/10.1016/j.agrformet.2024.109937

Long-term straw return to a wheat-maize system results in topsoil organic C saturation and increased yields while no stimulating or reducing yield-scaled N₂O and NO emissions. / Yao, Zhisheng; Wang, Yanqiang; Wang, Rui et al.
I: Agricultural and Forest Meteorology, Bind 349, 109937, 04.2024.

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avis › Tidsskriftartikel › Forskning › peer review

TY - JOUR

T1 - Long-term straw return to a wheat-maize system results in topsoil organic C saturation and increased yields while no stimulating or reducing yield-scaled N2O and NO emissions

AU - Yao, Zhisheng

AU - Wang, Yanqiang

AU - Wang, Rui

AU - Wang, Xiaogang

AU - Wang, Yan

AU - Zheng, Xunhua

AU - Liu, Chunyan

AU - Zhu, Bo

AU - Zhou, Minghua

AU - Liu, Yan

AU - Butterbach-Bahl, Klaus

PY - 2024/4

Y1 - 2024/4

N2 - Straw return to agricultural soils is considered as a key strategy to improve soil organic C (SOC) sequestration and crop production. However, changes in SOC can affect soil N-turnover and associated N2O and NO fluxes, as soil biogeochemical C- and N-cycles are strongly coupled. Understanding how and to what extent N-trace gas emissions per unit crop yield respond to changes in SOC following straw return, is critical for balancing food security and climate change mitigation. Here we report on an experiment in a Chinese wheat-maize system designed to understand the effects of long-term (2005–2020) different straw management options (straw return, burning or removal) on SOC stocks and yields, completed by N2O and NO flux measurements over the period 2016–2020. Our results showed that the increase in SOC stocks following straw return tended to level off over time, indicating that SOC saturation is reached after 12–13 years under straw return. Soil N-trace gas emissions showed high inter- and intra-annual variability, which were largely driven by changes in rainfall, soil hydrothermal conditions or soil C- and N-availability. Compared to straw burning or removal, long-term straw return increased annual N2O emissions by 9 %-49 %, to 2.72–2.98 kg N ha−1 yr−1, while NO emissions were decreased by 12 %-28 %, to 0.83–0.90 kg N ha−1 yr−1. The annual N2O emissions roughly offset the total C sink (SOC sequestration and CH4 uptake) by 40 %-46 %, but will override the climate benefits of total C sink as the SOC pool becomes saturated. However, because yields were higher in straw return treatments, yield-scaled annual N2O emissions remained unchanged. Our unique dataset allows for the first time a better understanding of the dynamics between SOC sequestration, yields and N-trace gas emissions, with results calling for action to address the risk of increasing N2O emissions following long-term SOC increases induced by straw return.

AB - Straw return to agricultural soils is considered as a key strategy to improve soil organic C (SOC) sequestration and crop production. However, changes in SOC can affect soil N-turnover and associated N2O and NO fluxes, as soil biogeochemical C- and N-cycles are strongly coupled. Understanding how and to what extent N-trace gas emissions per unit crop yield respond to changes in SOC following straw return, is critical for balancing food security and climate change mitigation. Here we report on an experiment in a Chinese wheat-maize system designed to understand the effects of long-term (2005–2020) different straw management options (straw return, burning or removal) on SOC stocks and yields, completed by N2O and NO flux measurements over the period 2016–2020. Our results showed that the increase in SOC stocks following straw return tended to level off over time, indicating that SOC saturation is reached after 12–13 years under straw return. Soil N-trace gas emissions showed high inter- and intra-annual variability, which were largely driven by changes in rainfall, soil hydrothermal conditions or soil C- and N-availability. Compared to straw burning or removal, long-term straw return increased annual N2O emissions by 9 %-49 %, to 2.72–2.98 kg N ha−1 yr−1, while NO emissions were decreased by 12 %-28 %, to 0.83–0.90 kg N ha−1 yr−1. The annual N2O emissions roughly offset the total C sink (SOC sequestration and CH4 uptake) by 40 %-46 %, but will override the climate benefits of total C sink as the SOC pool becomes saturated. However, because yields were higher in straw return treatments, yield-scaled annual N2O emissions remained unchanged. Our unique dataset allows for the first time a better understanding of the dynamics between SOC sequestration, yields and N-trace gas emissions, with results calling for action to address the risk of increasing N2O emissions following long-term SOC increases induced by straw return.

KW - Carbon saturation

KW - Cropland

KW - Emission factor

KW - Nitric oxide

KW - Nitrous oxide

KW - Soil carbon sequestration

KW - Straw return

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U2 - 10.1016/j.agrformet.2024.109937

DO - 10.1016/j.agrformet.2024.109937

M3 - Journal article

AN - SCOPUS:85186571208

SN - 0168-1923

VL - 349

JO - Agricultural and Forest Meteorology

JF - Agricultural and Forest Meteorology

M1 - 109937