CO_2 mitigation potential in farmland of China by altering current organic matter amendment pattern
XIE ZuBin1, LIU Gang1, BEI QiCheng1,2, TANG HaoYe1, LIU JinShan1,2, SUN HuiFeng1,2, XU YanPing1,2, ZHU JianGuo1 & CADISCH Georg3 1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; 2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China; 3 Institute of Plant Production and Agroecology in the Tropics and Subtropics, University of Hohenheim, Stuttgart 70593, Germany
The estimation of the global warming mitigation potential in terrestrial ecosystems is of great importance for decision makers to adopt measures to increase soil organic carbon (SOC) as well as to reduce greenhouse gas (GHGs) emissions. In this paper, we compiled data published in peer-reviewed journals, and conducted a holistic analysis of the effects of organic matter amendment on soil organic carbon sequestration, methane (CH4) and nitrous oxide (N2O) emissions in paddy and upland systems. Results showed that organic matter amendment increased soil organic carbon content, and apparent conversion rate of organic matter carbon to soil organic carbon in paddies was constant, while that in uplands decreased along with amendment years at 25 years time scale. Organic matter amendment during the rice season led to large CH4-C emissions, e.g on average 99.5 g CH4-C per kg organic carbon input under intermittent flood conditions, and 191.7 g CH4-C per kg organic carbon input under continuous flood conditions, respectively. By alteration of organic matter amendment from rice season to off-rice upland crop season, estimated CH4-C emissions in China could be cut by 3.5 Tg yr-1, accounting for 63% of current CH4-C emissions (5.5 Tg). If organic matter amendment percentage was increased from current 30% to future 50% of organic matter production and by alteration of organic matter amendment from rice season to off-rice upland crop season, the equivalent CO2-C mitigation potential in farmland of China would be 49.2 Tg yr-1 at the 10th year organic matter amendment and 36.0 Tg yr-1 at the 30th year amendment. These findings are important not only for China but also for the other rice production countries to increase farmland global warming mitigation.
【Fund】： supported by National Natural Science Foundation of China (Grant Nos.40871146 40571157);; Ministry of Science and Technology of China (Grant No. 2008BAD95B05);; Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No.KZCX2-YW-Q1-07);; Ministry of Agriculture of China (Grant No.200803033-B0204)
【CateGory Index】： S154
【CateGory Index】： S154