| 优化施肥模式对我国热带地区水稻-豇豆轮作系统N2O和CH4排放的影响 |
| 摘要点击 1555 全文点击 579 投稿时间：2019-05-14 修订日期：2019-06-25 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 优化施肥 热带地区 水稻-豇豆轮作 N2O CH4 增温潜势 |
| 英文关键词 optimizing fertilization tropical region paddy-cowpea rotation N2O CH4 global warming potential |
|
| 中文摘要 |
| 选择海南典型的水稻-豇豆轮作系统进行氧化亚氮（N2O）和甲烷（CH4）排放的原位监测，探究不同施肥模式下该系统土壤温室气体排放特征.试验设当地常规施肥对照（CON）、优化施肥量（OPT）、有机无机配施（ORG）、缓控肥替代优化（SCOPT）及不施氮对照（CK）共5个处理，采用静态箱-气相色谱法监测整个种植季土壤N2O和CH4排放，并估算增温潜势（GWP）和温室气体排放强度（GHGI）.结果表明，各处理水稻季N2O累积排放量为0.19~1.37 kg·hm-2，相较于CON处理，优化施肥处理N2O减排50%~86%；豇豆季N2O累积排放量为1.29~3.55 kg·hm-2，除ORG增加14%，其他处理减排16%~59%.各处理水稻季CH4累积排放量为4.67~14.23 kg·hm-2，CK、OPT和ORG处理分别较CON增加116%、22%和102%，而SCOPT减少了29%；豇豆季CH4累积排放量为0.03~0.26 kg·hm-2，期间出现CH4吸收.比较两个作物季和休闲期对农田土壤直接排放的温室气体GWP的贡献率，豇豆季在CH4排放极低的情况下，仍有44.7%~54.5%的占比；两种温室气体比较中，N2O对GWP的贡献率为66.7%~77.2%.SCOPT处理的GWP和两季作物GHGI均显著低于CON处理.3个优化施肥处理中，SCOPT的增产减排效果最显著，为最优的施肥方案. |
| 英文摘要 |
| In-situ measurement of nitrous oxide (N2O) and methane (CH4) emissions in a typical paddy-cowpea rotation system in Southern Hainan was conducted to determine the characteristics of greenhouse gas emissions under different optimum fertilization treatments. The experiment consisted of 5 treatments:conventional farming fertilization (CON), optimized fertilization (OPT), organic-inorganic fertilization (ORG), slow-controlled optimization fertilization (SCOPT), and no nitrogen as the control (CK). The N2O and CH4 emissions were measured using static chamber-gas chromatography during the all the paddy-cowpea rotation seasons. Global warming potential (GWP) and greenhouse gas intensity (GHGI) were also estimated in this study. The cumulative N2O emission during the rice growth season was 0.19-1.37 kg·hm-2. Compared with the CON treatment, other treatments reduced N2O emission by 50% to 86%. The cumulative N2O emission during the cowpea growth season was 1.29-3.55 kg·hm-2. In addition, N2O emission increased by 14% as a result of the ORG treatment, whereas that of the remaining treatments decreased by 16% to 59%. The cumulative CH4 emissions during the paddy growth season were 4.67-14.23 kg·hm-2. The CH4 emissions following the CK, OPT, and ORG treatments were higher by 116%, 22%, and 102%, respectively, whereas that of SCOPT was lower by 29%, than that following the CON treatment. Moreover, the cumulative CH4 emission during the cowpea growth season was 0.03-0.26 kg·hm-2, and CH4 absorption occurred during the same period. With regard to the contribution rate of different periods to GWP, the cowpea growth season still had a proportion of 44.7%-54.5%, despite extremely low CH4 emission. Regarding the two greenhouse gases, N2O contributed 66.7%-77.2%. During the entire rotation system, both GWP and GHGI processed by SCOPT were significantly lower than those of the CON treatments. To sum up, the SCOPT treatment was determined to be the optimal fertilization scheme in this study and had the most significant effects on increasing production and reducing greenhouse gas emissions. |
|
|
|
