Many researches showed a comprehensive assessment of the cropping practice effect on greenhouse gas （GHG） emissions per unit yield （yield-scaled） rather than per the land area （area-scaled）, and it was noteworth...Many researches showed a comprehensive assessment of the cropping practice effect on greenhouse gas （GHG） emissions per unit yield （yield-scaled） rather than per the land area （area-scaled）, and it was noteworthy that cropping practices decided to increase or decrease grain yield, and reduce or promote greenhouse gas emissions. In this study, a meta-analysis was conducted to quantify the effects of rice basic seedlings （BS） on the global warming potential （GWP） of GHG emissions at the yield-scale in China. The results suggested that significant difference was observed in yield-scaled GWP of BS. The lowest yield-scaled GWP occurred at 80-100 BS （415.65 kg CO2 equiv/mg）. The yield-scaled GHG emission from high to low was that of the hybrid rice varieties （1 028.86 kg CO2 equiv/mg）, the conventional rice varieties （634.15 kg CO2 equiv/mg） and the super rice varieties （576.57 kg CO2 equiv/mg）. Consequently, the model of conventional rice varieties and super rice varieties at 80-100 BS could be a scientifc method of matching inthe rice cropping system. A further assessment of rice density and variety impacts on GHG emissions at yield-scale was urgently needed to develop, so as to achieve win-win policies of rice production for higher yield with lower emissions.展开更多
文摘Many researches showed a comprehensive assessment of the cropping practice effect on greenhouse gas （GHG） emissions per unit yield （yield-scaled） rather than per the land area （area-scaled）, and it was noteworthy that cropping practices decided to increase or decrease grain yield, and reduce or promote greenhouse gas emissions. In this study, a meta-analysis was conducted to quantify the effects of rice basic seedlings （BS） on the global warming potential （GWP） of GHG emissions at the yield-scale in China. The results suggested that significant difference was observed in yield-scaled GWP of BS. The lowest yield-scaled GWP occurred at 80-100 BS （415.65 kg CO2 equiv/mg）. The yield-scaled GHG emission from high to low was that of the hybrid rice varieties （1 028.86 kg CO2 equiv/mg）, the conventional rice varieties （634.15 kg CO2 equiv/mg） and the super rice varieties （576.57 kg CO2 equiv/mg）. Consequently, the model of conventional rice varieties and super rice varieties at 80-100 BS could be a scientifc method of matching inthe rice cropping system. A further assessment of rice density and variety impacts on GHG emissions at yield-scale was urgently needed to develop, so as to achieve win-win policies of rice production for higher yield with lower emissions.
