title: [Effects of different rotation systems on greenhouse gas (CH₄ and N₂O) emissions in the Taihu Lake region, China].
abstract: We conducted a greenhouse gas emissions study of different rice-based cropping systems in the Taihu Lake region. The results indicated that the seasonal CH₄ emission initially increased, but declined over time. CH₄emission mainly occurred during the early stages of rice growth and decreased after the paddy soil dried. N₂O emission mainly occurred during the fertilizer application and paddy field drying stages. Compared with N20 emission, CH₄ emission contributed significantly more to the global warming potential (GWP) during the rice season. The proportion of CH4 emission to the total greenhouse gas emissions, which this study aimed to reduce, ranged from 94.7%-99.6%. CH₄emissions and their GWP during the rice season varied significantly under different rotation systems, with the order of wheat-rice rotation>Chinese milk vetch-rice rotation>fallow-rice rotation, while the N2O emissions and their GWP exhibited no significant differences. Compared with no nitrogen fertilization, applying N fertilizer significantly reduced CH₄ emission and GWP of the Chinese milk vetch-rice rotation. However, CH₄ emission and GWP did not vary with N application rates. The rice yield was largest when the N application rate was 240 kg · hm⁻². Taking economic and environmental benefits into account, we found that a N application rate of 240 kg · hm⁻² and a straw-return application of Chinese milk vetch not only reduced greenhouse gas emissions but also achieved the highest rice grain yield, which was recommended as a suitable cropping system for the Taihu Lake region.
authors.forename: An-yong
authors.initials: AY
authors.lastname: Hu
authors.forename: Xing
authors.initials: X
authors.lastname: Sun
authors.forename: Qin
authors.initials: Q
authors.lastname: Liu
mesh_terms: D000383:Agriculture / Q000379:methods*; D002681:China; D005308:Fertilizers; D005740:Gases / Q000032:analysis; D057232:Global Warming; D008697:Methane / Q000032:analysis*; D009584:Nitrogen; D009609:Nitrous Oxide / Q000032:analysis*; D012275:Oryza; D012621:Seasons; D012987:Soil; D014908:Triticum; D031306:Vicia
chemical_list: D005308:Fertilizers; D005740:Gases; D012987:Soil; D009609:Nitrous Oxide; D009584:Nitrogen; D008697:Methane