| 不同施肥措施对热带地区稻菜轮作体系土壤CH4和N2O排放的影响 |
| 摘要点击 1267 全文点击 422 投稿时间：2021-12-21 修订日期：2022-03-12 |
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| 中文关键词 固碳减排 全球增温潜势 有机肥替代化肥 稻菜轮作 热带地区 |
| 英文关键词 C sequestration and mitigation global warming potential substitution of chemical fertilizer with manure rice-vegetable rotation tropical region |
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| 中文摘要 |
| 研究稻菜轮作模式下土壤甲烷（CH4）和氧化亚氮（N2 O）排放对不同施肥措施的响应，对补充我国热带地区CH4和N2 O排放研究的不足具有重要的指导意义.在辣椒季设置4种施肥处理：磷钾肥（PK）、氮磷钾肥（NPK）、等氮条件下50%有机肥替代化肥（NPK+M）和100%有机肥替代（M），水稻种植季未设置施肥处理，研究辣椒季不同施肥条件下CH4和N2 O的排放规律以及对早稻生长季水稻产量、CH4和N2 O排放的后续影响.采用密闭静态箱-气相色谱法测定稻菜轮作土壤CH4和N2 O，同时测定作物产量，并估算全球增温潜势（GWP）和温室气体排放强度（GHGI）.结果表明：①辣椒季和早稻季4种施肥处理下土壤CH4的累积排放量分别为0.9~2.7 kg ·hm-2和5.5~8.4 kg ·hm-2，与NPK处理相比，辣椒季NPK+M和M处理CH4累积排放量分别减少35.3%和7.6%；而早稻季NPK+M和M处理CH4累积排放量均增加37.5%和55.1%，其中早稻季M处理达到显著水平.②辣椒季和早稻季4种施肥处理下N2 O的累积排放量分别为0.5~3.0 kg ·hm-2和0.3~0.5 kg ·hm-2，相对NPK处理，辣椒季NPK+M和M处理降低33.7%和16.0%的N2 O累积排放量，其中NPK+M处理达到显著差异，早稻季NPK+M处理N2 O累积排放量降低23.5%，M处理却增加9.1%，但均未达到显著水平.③ 4种施肥处理下辣椒和早稻的产量分别为3055.6~37722.5 kg ·hm-2和5850.9~6994.4 kg ·hm-2，与NPK处理相比，NPK+M和M处理显著增加辣椒产量.各施肥处理GWP为508.0~1864.4 kg ·hm-2，NPK+M和M处理相对NPK处理分别下降25.7%和5.7%，其中NPK+M处理达到显著差异.辣椒季各处理的GWP对总GWP的贡献率为69.2%~78.1%，N2 O对总GWP的贡献率为77.3%~85.3%.辣椒季和早稻季GHGI分别为0.03~0.09 kg ·kg-1和0.04~0.24 kg ·kg-1，与NPK处理相比，辣椒季M和NPK+M处理使GHGI显著下降71.5%和54.7%，早稻季NPK+M和M处理GHGI值分别下降44.0%和20.8%，其中NPK+M处理达到显著差异.综合作物产量及温室气体减排效果考虑，化肥和有机肥配施（NPK+M）可推荐为海南稻菜轮作模式下一种最优的减排稳产的施肥措施. |
| 英文摘要 |
| The study of the effects of different fertilization treatments on soil methane (CH4) and nitrous oxide (N2O) emissions in rice-vegetable rotation systems is of great significance to supplement the research gap on greenhouse gas emissions in tropical regions of China. In this study, four fertilization treatments were set up during the pepper season:phosphorus and potassium fertilizer application (PK); nitrogen, phosphorus, and potassium (NPK) application; half application of nitrogen, phosphorus, and potassium plus half application of organic fertilizer (NPK+M); and application of organic fertilizer (M). There was no fertilizer application during the following early rice season. The objective of our study was to investigate the rules of CH4 and N2O emissions under different fertilization treatments in the pepper growth season, and the effects of different fertilization treatments in the pepper growth season on rice yield, and CH4 and N2O emissions in the following early rice growth season. The close static chamber-gas chromatography method was applied to determine soil CH4 and N2O emissions. We measured crop yield, estimated global warming potential (GWP), and calculated greenhouse gas emission intensity (GHGI). Our results showed that:① the cumulative CH4 emission under the four fertilization treatments ranged between 0.9 kg·hm-2 to 2.7 kg·hm-2 during the pepper growth season and between 5.5 kg·hm-2 to 8.4 kg·hm-2 during the early rice growth season. Compared with NPK, NPK+M and M reduced the cumulative CH4 emission in the pepper growth season by 35.3% and 7.6%, respectively; however, NPK+M and M increased the cumulative CH4 emission in the early rice season by 37.5% and 55.1%, respectively. There was a significant difference in cumulative CH4 emission between M and NPK in the early rice growth season. ② The cumulative N2O emission under the four fertilization treatments varied from 0.5 kg·hm-2 to 3.0 kg·hm-2 in the pepper growth season and from 0.3 kg·hm-2 to 0.5 kg·hm-2 in the early rice growth season. The cumulative N2O emission was significantly decreased by 33.7% in NPK+M and by 16.0% in M, compared with that in NPK. In the early rice growth season, the cumulative N2O emission was decreased by 23.5% by NPK+M but was increased by 9.1% by M. There was no significant difference in the cumulative N2O emission among the four fertilization treatments. ③ The yields of pepper and early rice under the four fertilization treatments were 3055.6-37722.5 kg·hm-2 and 5850.9-6994.4 kg·hm-2, respectively. Compared with that in NPK, NPK+M and M significantly increased pepper yield. The GWP under the four fertilization treatments in the pepper-early rice rotation system varied from 508.0 kg·hm-2 to 1864.4 kg·hm-2. Compared with NPK, NPK+M significantly decreased GWP by 25.7% and M insignificantly decreased GWP by 5.7%. The pepper growth season with the four fertilization treatments contributed to 69.2%-78.1% of the total GWP, and N2O contributed to 77.3%-85.3% of the total GWP. The GHGI ranged between 0.03 kg·kg-1 and 0.09 kg·kg-1 in the pepper growth season and between 0.04 kg·kg-1 and 0.24 kg·kg-1 in the early rice growth season. Compared with that in NPK, both M and NPK+M significantly reduced the GHGI by 71.5% and 54.7%, respectively, in the pepper growth season. In the early rice season, NPK+M significantly decreased the GHGI by 44.0%, but M non-significantly decreased the GHGI by 20.8%. The peak in N2O emission in the tropical pepper-early rice rotation system appeared after fertilization, and N2O emissions primarily occurred in the pepper growth season. However, CH4 emission was mainly concentrated in the early rice season. Considering the overall enhancing effects on crop yield and mitigation of greenhouse gas emissions, the co-application of chemical and organic fertilizers (NPK+M) can be recommended as an optimal fertilization practice to mitigate greenhouse gas emissions and maintain crop yield in pepper-rice rotation systems of Hainan, China. |
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