不同耕作措施下冬小麦生长季农田二氧化碳排放通量及其与土壤温度的关系

利用长期定位试验研究了华北平原不同耕作措施下冬小麦生育期农田CO2排放通量,并对CO2排放通量和土壤温度进行了回归模拟.结果表明冬小麦生育期CO2排放速率表现为翻耕＞旋耕＞免耕,平均分别为343.69、337.54和190.47 mg·m-2·h-1.各处理冬小麦生育期CO2排放通量与土壤温度呈显著正相关;翻耕地CO2排放通量与10 cm地温相关性最高,旋耕地和免耕地则与10 cm和20 cm地温相关性较高.CO2排放通量和土壤温度呈指数函数关系(P＜0.01),利用10 cm地温对冬小麦生育期农田CO2排放通量进行估算表明,翻耕、旋耕和免耕地CO2排放分别为1.88、1.89和1.03 kg·m-2.

CO2 flux and its correlation with soil temperature in winter wheat growth season under different tillage measures

Based on a long-term experiment, this paper investigated the CO2 flux in winter wheat growth season under different tillage measures, and simulated the correlation between the flux and soil temperature by regression method. The results indicated that under different tillage measures, the average CO2 emission rate in winter wheat growth season was in the order of moldboard plow tillage (F) > minimum tillage (X) > no-tillage (M), with the value being 343.69, 337.54 and 190.47 mg x m(-2) x h(-1), respectively. There was a significant exponential correlation between CO2 flux and soil temperature, which was most significant for the soil temperature at the depth of 10 cm under F, and relatively significant for the soil temperature at the depth of 10 and 20 cm under X and M. Simulating with the soil temperature at the depth of 10 cm, the CO2 flux in winter wheat growth season was estimated as 1.88 kg x m(-2) under F, 1.89 kg x m(-2) under X, and 1.03 kg x m(-2) under M.