Chen You-de, Zhao Yang, Gao Du-Juan, Luo Xian-Fu, Cui Ting, Tong Zhong-Quan, Wu Jia-Mei
Hunan Rice Research Institute, Changsha 410125, China.
Nanxian Agricultural and Rural Bureau, Nanxian 413200, China.
Huan Jing Ke Xue. 2020 Oct 8;41(10):4701-4710. doi: 10.13227/j.hjkx.202002107.
A field experiment was carried out to investigate the effects of different rice-rape rotation systems on methane and nitrous oxide emissions, which were measured using the static chamber/gas chromatography method, prediction of their global warming potentials (GWP), and greenhouse gas intensity (GHGI) in paddy fields. The results showed that the average cumulative emissions of CHfrom a double cropping paddy field, single season rice field (including middle or late), rape field, and leisure land were 135.25, 55.64, 5.05, and 1.89 kg ·hm, respectively. The CH emission during the rice season accounted for 91.8%-98.5% of the annual CH emission in different rotation years, and the contents of dissolved organic carbon in paddy soil exhibited a significantly positive correlation with CH emission. The CH emission in conventional late rice paddy was 18.7% higher than that of hybrid late rice paddy (<0.05). The average cumulative emissions of NO from double cropping paddy field, single season rice field (including middle or late), rape field, and leisure land were 0.94, 0.64, 1.38, and 0.24 kg ·hm, respectively. Out of the total annual NO emission, 57.2% to 70.2% was from the rape field; 17.8% and 30.6% was due to the winter fallow treatments with previous crop type of double corpping rice and single season rice, respectively. There was no significant difference in NO emission between hybrid rice and conventional rice paddy fields. The GWP of double cropping rice-winter fallow and double cropping rice-rape was higher than that of rice-rape and rice-winter fallow, and the GWP of CH in rice season accounted for 71.2% to 90.9% of the annual GWP of rotation. The highest treatment of GHGI was rice-rice-rape, and the treatment of rice-oil and rice-winter slack was lower. According to the comprehensive environmental and economic benefits, the late hybrid rice-rape patterns should be selected to reduce greenhouse gases in multiple cropping rice fields of South China.
开展了一项田间试验，以研究不同稻油轮作系统对甲烷和氧化亚氮排放的影响，采用静态箱/气相色谱法对其进行测量，并预测其全球变暖潜能值（GWP）以及稻田温室气体强度（GHGI）。结果表明，双季稻田、单季稻田（包括中稻或晚稻）、油菜田和休闲地的CH平均累积排放量分别为135.25、55.64、5.05和1.89 kg·hm。在不同轮作年份，水稻季的CH排放量占全年CH排放量的91.8% - 98.5%，稻田土壤中溶解有机碳含量与CH排放量呈显著正相关。常规晚稻田的CH排放量比杂交晚稻田高18.7%（<0.05）。双季稻田、单季稻田（包括中稻或晚稻）、油菜田和休闲地的NO平均累积排放量分别为0.94、0.64、1.38和0.24 kg·hm。在全年NO排放总量中，57.2%至70.2%来自油菜田；17.8%和30.6%分别归因于前茬作物为双季稻和单季稻的冬闲处理。杂交稻田和常规稻田的NO排放无显著差异。双季稻-冬闲和双季稻-油菜的GWP高于稻-油和稻-冬闲，水稻季CH的GWP占轮作年GWP的71.2%至90.9%。GHGI最高的处理是稻-稻-油菜，稻-油和稻-冬闲处理较低。根据综合环境和经济效益，应选择晚熟杂交稻-油菜模式以减少中国南方多熟制稻田的温室气体排放。
