摘要
以黏土为研究对象,利用地表灌水（SI）和不同深度的地下灌水（SDI12、SDI15和SDI18）实现了不同的水分垂直非均匀分布,研究了不同水分分布下的旱地土壤CO2日排放特征。结果表明：不同的处理的CO2排放呈现相同的日变化规律,但不同处理间排放量存在差异;两次灌水后CO2日平均排放通量之间的大小关系均表现为SI〉SDI12〉SDI15〉SDI18,且SI处理在初次灌水后的排放通量显著大于SDI15和SDI18处理,而第二次灌水后各处理之间均有明显的差异性。各处理在两次灌水后同一观测日内,其0-12 cm土层的土壤水分WFPS之间的大小关系分别为：SI〉SDI12〉SDI15〉SDI18和SI〈SDI12〈SDI15〈SDI18。对同一处理来说,其土壤0-12 cm土层的平均含水率在不同观测日均呈现出逐渐递减趋势,相应的初次灌水后CO2日平均排放通量呈现出逐渐递增的趋势,而第二次灌水后SI和SDI12处理呈现出逐渐递增的趋势,SDI15和SDI18则呈现出先递减后递增的趋势。此外,比较第一次和第二次灌水后的CO2排放,发现季节温度变化是影响CO2日排放重要因素,CO2的排放随着温度的升高而增加,而温度过高时,CO2的排放随温度升高出现降低的趋势。
Both surface irrigation （SI） and subsurface irrigation at three different depths （SDI12, SDI15 and SDI18） were applied twice on a clay soil, to achieve different vertical non-uniform soil moisture distribution patterns. Then the CO2 emissions were measured to analyze the diurnal variation characteristics of CO2 emission from upland soil that under the different soil moisture distribution patterns. The CO2 emission from different soil moisture distribution patterns varied diurnally in similar pattern, but it resulted in different in CO2 emission fluxes among different treatments. The CO2 emission fluxes form different treatments were generally in the sequence of SI〉 SDI12〉SDI15〉SDI18 after both irrigation events. The CO2 fluxes form different treatments are significantly different to each other after the second irrigation, and the CO2 fluxes form SI treatment significantly higher than those from SDI15 and SDI18 treatments after first irrigation. The soil WFPS in 0- 12 cm soil layer were generally in the sequence of SI〉SDI12〉SDI15〉SDI18 after the first irrigation, and SI〈SDI12〈SDI15〈SDI18 after the second irrigation. The soil WFPS generally decreased gradually along with the time after both irrigation. The CO2 fluxes from each treatment decreased with the decrease in soil moisture after first irrigation, but the CO2 fluxes from SI and SDI12 increased with the decrease in soil moisture after the second irrigation. The difference in the CO2 fluxes between the results after first and second irrigation also indicated that the seasonal tem- perature variation is the predominate factor in determining the soil CO2 emission form soil. The CO2 emission generally increased as the temperature rises, but when the temperature is too high （ higher than 35 ℃ ）, the CO2 emission decrease with temperature rise.
作者
徐俊增
张庆
王艳华
王飞
孙勇
卫琦
XU Jun-zeng ZHANG Qing WANG Yan-hua WANG Fei SUN Yong WEI Qi(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China Water Diversion and Irrigation Engineering Technology Center,Yellow River Institute of Hydraulic Research,Xinxiang 453003, Henan Province, China Water Conservancy Bureau of Gaoyou, Gaoyou 225600, Jiangsu Province, China)
出处
《中国农村水利水电》
北大核心
2016年第11期125-129,132,共6页
China Rural Water and Hydropower
基金
国家自然科学基金项目(51179051)
国家重点实验室自主研究项目(20145027912)
江苏高校优势学科建设工程资助项目
关键词
水分垂直非均匀分布
CO2排放通量
日变化
土壤充水孔隙度
灌水方式
moisture vertical non-uniform distribution
CO2 emission fluxes
diurnal pattern
water filled porosity
irrigation methods
