川中丘陵水旱轮作土壤—小麦系统CO_2排放及其影响因素

CO_2 EMISSION FROM SOIL-WHEAT SYSTEM IN A PADDY-DRYLAND ROTATION AREA IN THE CENTRAL SICHUAN BASIN AND ITS INFLUENCE FACTORS

利用静态箱/气相色谱法对川中丘陵区水旱轮作区的小麦进行全生长季CO_2排放观测。结果表明:①土壤—小麦系统的CO_2排放通量存在着明显的日变化。凌晨4:00～6:00排放量最低,随着温度的升高,CO_2的排放量逐渐增大,在午后1:00～3:00达到峰值。分析表明,气温和地表温度与土壤—小麦系统CO_2排放通量之间存在显著的相关关系。②土壤—小麦系统CO_2排放都有明显的季节变化。分析表明,小麦生物量和气温与土壤—小麦系统CO_2排放季节变化之间存在显著的相关关系。③在小麦各个生育期中,CO_2平均排放通量常规处理>无氮处理>空白>裸地。水早轮作区小麦常规处理、无氮处理、空白点和裸地的CO_2排放通量的平均值分别为574.51、362.23、239.92、129.47 mg/(m^2·h)。

CO_2emission from soil-wheat system in a paddy field-dryland rotation area in purple soil were measured by static chamber-gas chromatographic techniques in the central Sichuan Basin. Results showed: ① CO_2 emission from soil-wheat system varified remarkably daily. The emission of CO_2 was at the lowest stage between 4: 00 and 6:00 before dawn, and it was crescent and reached peak value between 1:00 and 3:00 in the afternoon with the rising of temperature. Analyses showed that there were significant relation...