| 刘全全,王俊,付鑫,刘文兆,Upendra M. Sainju.不同覆盖措施对黄土高原旱作农田N2O通量的影响[J].干旱地区农业研究,2016,34(3):115~122 |
| 不同覆盖措施对黄土高原旱作农田N2O通量的影响 |
| Effects of different mulching measures on soil N2O flux in rainfed winter wheat fields in the Loess Plateau of China |
| |
| DOI：10.7606/j.issn.1000-7601.2016.03.18 |
| 中文关键词: 冬小麦 旱作农田 覆盖 N2O通量 土壤温度 土壤水分 |
| 英文关键词:winter water dryland farming mulching N2O flux soil temperature soil moisture |
| 基金项目:国家自然科学基金项目(31270484，41171033)；西北大学研究生自主创新项目（YZZ13006） |
|
| 摘要点击次数: 1379 |
| 全文下载次数: 696 |
| 中文摘要: |
| 为研究秸秆和地膜覆盖条件下旱作冬小麦田N2O通量变化及水热状况，在中国科学院长武农业生态试验站采用静态箱-气相色谱法测定了冬小麦种植期间无覆盖处理（CK）、地膜覆盖处理（PM）、全年覆盖秸秆处理4 500 kg·hm-2（M4500）和全年覆盖秸秆9 000 kg·hm-2处理（M9000）土壤N2O排放通量，并同步测定了土壤水分、土壤温度和气温。研究表明：CK、PM、M4500和M9000处理生育期内N2O通量范围分别为17.24～321.86、19.03～388.00、21.57～344.53 μg·m-2·h-1和24.77～348.42 μg·m-2·h-1，生育期内N2O平均排放通量分别为110.64、146.48、131.31 μg·m-2·h-1和142.26 μg·m-2·h-1，与CK相比，PM、M4500和M9000处理N2O平均排放通量分别提高了32.29%、18.68%和28.57%，其中，PM和M9000处理与CK之间差异达极显著水平（P＜0.01）。PM处理N2O累积排放量（7.25 kg·hm-2）较CK处理（5.18 kg·hm-2）提高了40%（P＜0.05），秸秆覆盖处理M4500（6.30 kg·hm-2）和M9000（7.17 kg·hm-2）N2O累积排放量较CK处理分别提高23%和38%（P＜0.05），PM和M9000处理N2O累积排放量显著高于M4500，PM和M9000处理之间无显著差异。不同覆盖条件下生育期N2O通量表现出明显的季节变化特征，小麦生长季始末期较高中期较低，N2O排放受降水影响明显。生育期N2O累积通量主要源于冬小麦拔节期至收获期，PM、M4500和M9000处理拔节期至收获期N2O排放量分别占整个生育期的41%、40%和43%，均高于CK（38%）处理。土壤温度变化可以解释69%～76%土壤N2O通量变化，土壤水分仅解释了37%～51%的土壤N2O通量变化。回归分析表明无覆盖时，土壤水分是影响土壤N2O排放的关键因子，秸秆覆盖和地膜覆盖条件下土壤温度是影响土壤N2O排放的关键因子。覆盖秸秆4 500 kg·hm-2是黄土旱塬区较为适宜的冬小麦栽培模式。 |
| 英文摘要: |
| Soil N2O flux and its responses to soil moisture and soil temperature under different mulching measures during the period of winter wheat growth were investigated at Changwu Agro-Ecological Research Station in the Loess Plateau of Changwu County, Shaanxi Province, China. The soil N2O flux rate, soil moisture and soil temperature were determined by the static chamber technique in the winter wheat field, with four mulching practices, including the control without mulching (CK), plastic film mulching (PM), two rates of 4 500 kg·hm-2 and 9 000 kg·hm-2 with straw mulching (M4500 and M9000) year-round. The results showed that the range of N2O flux during growth period for CK, PM, M4500 and M9000 were 17.24～321.86, 19.03～388.00, 21.57～344.53 μg·m-2·h-1 and 24.77～348.42 μg·m-2·h-1, respectively. The average N2O flux rates were 110.64, 146.48, 131.31 μg·m-2·h-1 and 142.26 μg·m-2·h-1 for the CK, PM, M4500 and M9000 treatments during the growth period, respectively. Compared to the CK treatment, the average N2O flux rates were increased by 32.39% for PM, 18.68% for M4500 and 28.57% for M9000. The cumulative N2O emissions for PM (7.25 kg·hm-2), M4500 (6.30 kg·hm-2) and M9000 (7.17 kg·hm-2) treatments were increased by 40%, 23% and 38% compared to CK (5.18 kg·hm-2), respectively, and PM and M9000 treatments significantly (P<0.05) increased the cumulative N2O emissions compared to M4500. No significant difference was found between PM and M9000. The obvious seasonal variation characteristics in the N2O flux were observed under all mulching measures, and the N2O flux was relative higher at the beginning and the end of the winter wheat growth peroid than that in the middle of the growth period. The cumulative N2O emission from jointing stage to harvest accounted for 41%, 40% and 43% of the total emission for PM, M4500 and M9000 treatments, which were higher than that in CK. Soil temperature itself could explain more than 69%～76% (R2＞0.43) variations in soil N2O flux, and soil water content only explained 37%～51% variations in soil N2O flux. The regression models including both soil temperature and soil moisture demonstrate that soil moisture is the dominant factor affecting soil N2O flux under the control without mulching, and soil temperature was the dominant factor affecting soil N2O flux under plastic film mulching and straw mulching. Straw mulching at a rate of 4 500 kg·hm-2 might be an appropriate way in the Loess Plateau. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
| | |