Impacts of rice varieties and management on yield-scaled greenhouse gas emissions from rice fields in China: A meta-analysis
Increasing numbers of studies have suggested that a comprehensive assessment of the impacts of cropping practices on greenhouse gas (GHG) emissions per unit yield (yield-scaled), rather than by land area (area-scaled), is needed to inform trade-off decisions to increase yields and reduce GHG emissio...
Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2014-07-01
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Series: | Biogeosciences |
Online Access: | http://www.biogeosciences.net/11/3685/2014/bg-11-3685-2014.pdf |
Summary: | Increasing numbers of studies have suggested that a comprehensive assessment
of the impacts of cropping practices on greenhouse gas (GHG) emissions per
unit yield (yield-scaled), rather than by land area (area-scaled), is needed
to inform trade-off decisions to increase yields and reduce GHG emissions. We
conducted a meta-analysis to quantify impacts of rice varieties on the global
warming potential (GWP) of GHG emissions at the yield scale in China. Our
results showed that significantly higher yield-scaled GWP occurred with
indica rice varieties (1101.72 kg CO<sub>2</sub> equiv. Mg<sup>−1</sup>) than
japonica rice varieties (711.38 kg CO<sub>2</sub> equiv. Mg<sup>−1</sup>). Lower
yield-scaled GHG emissions occurred within 120–130 days of growth duration
after transplanting (GDAT; 613.66 kg CO<sub>2</sub> equiv. Mg<sup>−1</sup>), followed
by 90–100 days of GDAT (749.72 kg CO<sub>2</sub> equiv. Mg<sup>−1</sup>, 100–110
days of GDAT (794.29 kg CO<sub>2</sub> equiv. Mg<sup>−1</sup>), and 70–80 days of
GDAT (800.85 kg CO<sub>2</sub> equiv. Mg<sup>−1</sup>). The fertilizer rate of
150–200 kg N ha<sup>−1</sup> resulted in the lowest yield-scaled GWP.
Consequently, appropriate cultivar choice and pairs were of vital importance
in the rice cropping system. A further life cycle assessment of GHG emissions
among rice varieties at the yield scale is urgently needed to develop
win–win policies for rice production to achieve higher yield with lower
emissions. |
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ISSN: | 1726-4170 1726-4189 |