Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 13, issue 9
Biogeosciences, 13, 2701–2714, 2016
https://doi.org/10.5194/bg-13-2701-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Biogeosciences, 13, 2701–2714, 2016
https://doi.org/10.5194/bg-13-2701-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 10 May 2016

Research article | 10 May 2016

Global warming potential and greenhouse gas intensity in rice agriculture driven by high yields and nitrogen use efficiency

Xiaoxu Zhang1, Xin Xu1, Yinglie Liu1, Jinyang Wang1,2, and Zhengqin Xiong1 Xiaoxu Zhang et al.
  • 1Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
  • 2State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China

Abstract. Our understanding of how global warming potential (GWP) and greenhouse gas intensity (GHGI) is affected by management practices aimed at food security with respect to rice agriculture remains limited. In the present study, a field experiment was conducted in China to evaluate the effects of integrated soil–crop system management (ISSM) on GWP and GHGI after accounting for carbon dioxide (CO2) equivalent emissions from all sources, including methane (CH4) and nitrous oxide (N2O) emissions, agrochemical inputs and farm operations and sinks (i.e., soil organic carbon sequestration). The ISSM mainly consisted of different nitrogen (N) fertilization rates and split, manure, Zn and Na2SiO3 fertilization and planting density for the improvement of rice yield and agronomic nitrogen use efficiency (NUE). Four ISSM scenarios consisting of different chemical N rates relative to the local farmers' practice (FP) rate were carried out, namely, ISSM-N1 (25 % reduction), ISSM-N2 (10 % reduction), ISSM-N3 (FP rate) and ISSM-N4 (25 % increase). The results showed that compared with the FP, the four ISSM scenarios significantly increased the rice yields by 10, 16, 28 and 41 % and the agronomic NUE by 75, 67, 35 and 40 %, respectively. In addition, compared with the FP, the ISSM-N1 and ISSM-N2 scenarios significantly reduced the GHGI by 14 and 18 %, respectively, despite similar GWPs. The ISSM-N3 and ISSM-N4 scenarios remarkably increased the GWP and GHGI by an average of 69 and 39 %, respectively. In conclusion, the ISSM strategies are promising for both food security and environmental protection, and the ISSM scenario of ISSM-N2 is the optimal strategy to realize high yields and high NUE together with low environmental impacts for this agricultural rice field.

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The intensive agriculture is facing environmental problems due to low nitrogen use efficiency (NUE) in China. Integrated soil-crop system management (ISSM) has been developed to increase crop yield and NUE. We investigated greenhouse gas intensity after accounting for CO2 emissions from all sources, including methane and nitrous oxide emissions, agrochemical inputs and farm operations and sinks. We found that the ISSM strategies are promising for both food security and environmental protection.
The intensive agriculture is facing environmental problems due to low nitrogen use efficiency...
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