Assessing alternatives for mitigating net greenhouse gas emissions and increasing yields from rice production in china over the next twenty years
Assessing alternatives for mitigating net greenhouse gas emissions and increasing yields from rice production in china over the next twenty years
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DOI：
10.2134/jeq2005.0208
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发表时间：
2006-07-01
影响因子：
2.4
通讯作者：
Rose, Steven
中科院分区：
文献类型：
--
作者：
Li, Changsheng;Salas, William;Rose, Steven
对水稻系统温室气体减排效果的评估通常是在实地研究的基础上进行的。空间明确的过程模型，如反硝化和分解（DNDC）模型，可以加强从实地研究到国家尺度的替代管理做法的缓解潜力的外推。我们的目标是分析缓解替代方案、水、肥料和稻草管理对温室气体净排放（二氧化碳、甲烷和一氧化二氮通量）、产量和用水的影响。在构建了土壤、气候、水稻种植面积和系统以及管理实践的GIS数据库后，我们对中国约2500个县进行了21年替代管理方案的DNDC。结果表明，尽管大规模采用季中排水，中国稻田仍有很大的潜力在2000-2020年期间减少20%至60%的甲烷。然而，减少CH4排放管理的变化同时影响土壤碳动态和N2O排放，从而可以重新排列技术减缓效果的排名。温室气体净减排效果的排序为旱稻bb0浅淹>硫酸铵>季中排水>淡季秸秆>缓释肥料>连续淹水。大多数管理备选方案产生的收益率与基线相当；然而，持续的洪水和旱稻显著降低了产量。水管理战略似乎是技术上最有希望的温室气体缓解替代方案，浅层洪水提供了节约用水和提高产量的额外好处。
Assessments of the efficacy of mitigation of greenhouse gas (GHG) emissions from paddy rice systems have typically been analyzed based on field studies. Extrapolation of the mitigation potential of alternative management practices from field studies to a national scale may be enhanced by spatially explicit process models, like the DeNitrification and DeComposition (DNDC) model. Our objective was to analyze the impacts of mitigation alternatives, management of water, fertilizer, and rice straw, on net GHG emissions (carbon dioxide, methane, and nitrous oxide fluxes), yields, and water use. After constructing a GIS database of soil, climate, rice cropping area and systems, and management practices, we ran DNDC with 21-yr alternative management schemes for each of the approximately 2500 counties in China. Results indicate that, despite large-scale adoption of midseason drainage, there is still large potential for additional methane reductions from Chinese rice paddies of 20 to 60% over 2000-2020. However, changes in management for reducing CH4 emissions simultaneously affect soil carbon dynamics as well as N2O emissions and can thereby reorder the ranking of technical mitigation effectiveness. The order of net GHG emissions reduction effectiveness found here is upland rice > shallow flooding > ammonium sulfate > midseason drainage > off-season straw > slow-release fertilizer > continuous flooding. Most of the management alternatives produced yields comparable to the baseline; however, continuous flooding and upland rice significantly reduced yields. Water management strategies appear to be the most technically promising GHG mitigation alternatives, with shallow flooding providing additional benefits of both water conservation and increased yields.