[Objective] This study aimed to investigate the effect of direct-seeding with non-flooding and wheat residue returning patterns on greenhouse gas emission from rice paddy. [Method] Two rice cultivars currently used in...[Objective] This study aimed to investigate the effect of direct-seeding with non-flooding and wheat residue returning patterns on greenhouse gas emission from rice paddy. [Method] Two rice cultivars currently used in the production, Yangdao 6 （an indica） and Yangjing 4038 （a japonica）, were field grown using a direct-seeding method, and four treatments, wheat straw incorporation into soil and traditional flooding （SlF）, non-flooding and wheat straw mulching （NSM）, non-flooding and wheat straw incorporation into soil （NSl） and traditional flooding （no straw returned, Control, TF）, were imposed after sowing to maturity. Effects of direct-seeding with non-flooding and wheat residue returning patterns on CH4, N20 and CO2 emissions were investigated by using the method of static chamber-gas chromatographic tech- niques. [Result] Grain yield showed no significant difference between non-flooding and flooding treatments, but was significantly higher under the SlF than under any other treatments. The emission flux of CH4 and CO2 under TF and SlF exhibited a single peak curve, while changed little under the NSl and NSM The emission flux of N2Oshowed multiple perk curves for all the treatments. Compared with TF, SlF significantly increased mean emission flux of CH4 or N2O, decreased emission of N20, while NSl and NSM significantly decreased the mean emission flux of OH4, and increased emission flux of N2O and CO2. SIF also increased Green Warm Potential （GWP） of CH4, N2O and CO2 and the GWP per unit grain yield by 47.3%- 53.7% and 32.2%-39.4%, respectively. Both NSl and NSM decreased GWP by 24.2%-29.6% and 30.1%-35.5%, and the GWP per unit grain yield was decreased by 21.7-27.2% and 25.6%-31.1%, respectively. [Conelusion] both NSl and NSM could significantly reduce greenhouse effect of CH4, N2O and CO2 meanwhile maintain a high grain yield.展开更多
CH4, N2O and CO2 emissions from northeast Chinese rice fields were measured in the fallow season （November to March） to investigate the effects of freezing-thawing on the emissions. Both CH4 emission from and atmosp...CH4, N2O and CO2 emissions from northeast Chinese rice fields were measured in the fallow season （November to March） to investigate the effects of freezing-thawing on the emissions. Both CH4 emission from and atmospheric CH4 oxidation by the soil occurred, but the flux was small. During the fallow season, rice fields acted as a minor source of atmospheric CH4, which accounted for about 1% of the CH4 emission during the rice growing period. The field was also a substantial source of atmospheric N20, which ranged between 40 to 77 mg m-2 and eu=counted for 40%-50% of the annual N20 emission. The largest N20 flux was observed in the thawing period during the fallow season. Laboratory incubation tests showed that the largest N20 flux came from the release of N20 trapped in frozen soil. Tillage and rice straw application （either mulched on the soil surface or incorporated in the soil） stimulated the CH4 and CO2 emissions during the fallow season, but only straw application stimulated N2O emission substantially.展开更多
Rice paddies are increasingly being converted to vegetable production due to economic benefits related,in part,to changes in demand during recent decades.Here,we implemented a parallel field experiment to simultaneous...Rice paddies are increasingly being converted to vegetable production due to economic benefits related,in part,to changes in demand during recent decades.Here,we implemented a parallel field experiment to simultaneously measure annual emissions of CH_4and N_2O,and soil organic carbon(SOC)stock changes,in rice paddies(RP),rice paddy–converted conventional vegetable fields(CV),and rice paddy–converted greenhouse vegetable fields(GV).Changing from rice to vegetable production reduced CH_4emissions by nearly 100%,and also triggered substantial N_2O emissions.Furthermore,annual N_2O emissions from GV significantly exceeded those from CV due to lower soil p H and higher soil temperature.Marginal SOC losses occurred after one year of cultivation of RP,CV,and GV,contributing an important share(3.4%,32.2%,and 10.3%,respectively)of the overall global warming potential(GWP)balance.The decline in CH_4emissions outweighed the increased N_2O emissions and SOC losses in CV and GV,leading to a 13%–30%reduction in annual GWP as compared to RP.These results suggest that large-scale expansion of vegetable production at the expense of rice paddies is beneficial for mitigating climate change in terms of the overall GWP.展开更多
基金Supported by National Natural Science Foundation of China(31371562,31301276)Special Fund for Fundamental Scientific Research Business of Central Public Research Institutes(Agriculture)(201103003+2 种基金201203079)Key Projects in the National Science&Technology Pillar Program during the 12thFive-year Plan Period(2012BAD04B08)Fund for Independent Innovation of Agricultural Sciences in Jiangsu Province(CX(14)5021)~~
文摘[Objective] This study aimed to investigate the effect of direct-seeding with non-flooding and wheat residue returning patterns on greenhouse gas emission from rice paddy. [Method] Two rice cultivars currently used in the production, Yangdao 6 （an indica） and Yangjing 4038 （a japonica）, were field grown using a direct-seeding method, and four treatments, wheat straw incorporation into soil and traditional flooding （SlF）, non-flooding and wheat straw mulching （NSM）, non-flooding and wheat straw incorporation into soil （NSl） and traditional flooding （no straw returned, Control, TF）, were imposed after sowing to maturity. Effects of direct-seeding with non-flooding and wheat residue returning patterns on CH4, N20 and CO2 emissions were investigated by using the method of static chamber-gas chromatographic tech- niques. [Result] Grain yield showed no significant difference between non-flooding and flooding treatments, but was significantly higher under the SlF than under any other treatments. The emission flux of CH4 and CO2 under TF and SlF exhibited a single peak curve, while changed little under the NSl and NSM The emission flux of N2Oshowed multiple perk curves for all the treatments. Compared with TF, SlF significantly increased mean emission flux of CH4 or N2O, decreased emission of N20, while NSl and NSM significantly decreased the mean emission flux of OH4, and increased emission flux of N2O and CO2. SIF also increased Green Warm Potential （GWP） of CH4, N2O and CO2 and the GWP per unit grain yield by 47.3%- 53.7% and 32.2%-39.4%, respectively. Both NSl and NSM decreased GWP by 24.2%-29.6% and 30.1%-35.5%, and the GWP per unit grain yield was decreased by 21.7-27.2% and 25.6%-31.1%, respectively. [Conelusion] both NSl and NSM could significantly reduce greenhouse effect of CH4, N2O and CO2 meanwhile maintain a high grain yield.
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No.G1999011805).
文摘CH4, N2O and CO2 emissions from northeast Chinese rice fields were measured in the fallow season （November to March） to investigate the effects of freezing-thawing on the emissions. Both CH4 emission from and atmospheric CH4 oxidation by the soil occurred, but the flux was small. During the fallow season, rice fields acted as a minor source of atmospheric CH4, which accounted for about 1% of the CH4 emission during the rice growing period. The field was also a substantial source of atmospheric N20, which ranged between 40 to 77 mg m-2 and eu=counted for 40%-50% of the annual N20 emission. The largest N20 flux was observed in the thawing period during the fallow season. Laboratory incubation tests showed that the largest N20 flux came from the release of N20 trapped in frozen soil. Tillage and rice straw application （either mulched on the soil surface or incorporated in the soil） stimulated the CH4 and CO2 emissions during the fallow season, but only straw application stimulated N2O emission substantially.
文摘Rice paddies are increasingly being converted to vegetable production due to economic benefits related,in part,to changes in demand during recent decades.Here,we implemented a parallel field experiment to simultaneously measure annual emissions of CH_4and N_2O,and soil organic carbon(SOC)stock changes,in rice paddies(RP),rice paddy–converted conventional vegetable fields(CV),and rice paddy–converted greenhouse vegetable fields(GV).Changing from rice to vegetable production reduced CH_4emissions by nearly 100%,and also triggered substantial N_2O emissions.Furthermore,annual N_2O emissions from GV significantly exceeded those from CV due to lower soil p H and higher soil temperature.Marginal SOC losses occurred after one year of cultivation of RP,CV,and GV,contributing an important share(3.4%,32.2%,and 10.3%,respectively)of the overall global warming potential(GWP)balance.The decline in CH_4emissions outweighed the increased N_2O emissions and SOC losses in CV and GV,leading to a 13%–30%reduction in annual GWP as compared to RP.These results suggest that large-scale expansion of vegetable production at the expense of rice paddies is beneficial for mitigating climate change in terms of the overall GWP.
