title: Mitigating effects of ex situ application of rice straw on CH4and N2O emissions from paddy-upland coexisting system.
abstract: The in situ application of rice straw enhances CH4emissions by a large margin. The ex situ application of rice straw in uplands, however, may mitigate total global warming potential (GWP) of CH4and N2O emissions from paddy-upland coexisting systems. To evaluate the efficiency of this practice, two field trials were conducted in rice-rice-fallow and maize-rape cropping systems, respectively. Year-round measurements of CH4and N2O emissions were conducted to evaluate the system-scaled GWP. The results showed that CH4accounted for more than 98% of GWP in paddy. Straw removal from paddy decreased 44.7% (302.1 kg ha-1yr-1) of CH4emissions and 51.2% (0.31 kg ha-1yr-1) of N2O emissions, thus decreased 44.8% (7693 kg CO2-eqv ha-1yr-1) of annual GWP. N2O accounted for almost 100% of GWP in upland. Straw application in upland had insignificant effects on CH4and N2O emissions, which increased GWP only by 91 kg CO2-eqv ha-1yr-1. So, the transfer of straw from paddy to upland could decrease GWP by 7602 kg CO2-eqv ha-1yr-1. Moreover, straw retention during late rice season contributed to 88.2% of annual GWP increment. It is recommended to transfer early rice straw to upland considering GWP mitigation, nutrient recycling and labor cost.
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, Hunan, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wu
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China.
authors.forename: Anlei
authors.initials: A
authors.lastname: Chen
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Xie
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China.
authors.forename: Yunqiu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China.
authors.forename: Chunmei
authors.initials: C
authors.lastname: Yin
mesh_terms: D000383:Agriculture; D057232:Global Warming; D008697:Methane / Q000032:analysis*; D009609:Nitrous Oxide / Q000032:analysis*; D012275:Oryza / Q000737:chemistry*; D011891:Rain; D012987:Soil; D013696:Temperature; D014866:Waste Products / Q000032:analysis*
chemical_list: D012987:Soil; D014866:Waste Products; D009609:Nitrous Oxide; D008697:Methane