沟埋还田方式下不同埋草量对冬季稻田CO2排放的影响

采用了碱液吸收法对冬季稻田CO2排放进行了田间原位测定,探讨了水旱轮作水稻季秸秆沟埋还田方式下不同埋草量对越冬稻田土壤CO2排放的影响,分析了不同处理单位草量与CO2排放通量之间的关系,并对不同单位沟埋草量的越冬稻田裸田CO2季节排放量进行了估算。结果表明：CO2通量和季节排放量与埋草量的变化规律基本一致,各处理平均CO2通量在51.25 mg.m-2.h-1~84.92 mg.m-2.h-1之间,不同处理之间差异不显著。各处理季节排放量为1 591.40mg.m-2.h-1~1 936.12 kg.hm-2,各处理平均CO2通量和CO2季节排放量均小于空白对照。单位草量CO2通量随埋草量的增加而下降,变化范围为10.63 mg.m-2.h-1~30.69 mg.m-2.h-1,处理Ⅰ与其它处理之间差异显著（P〈0.05）。

Effects of Different Amount of Ditch -buried Straw on CO2 Flux from Paddy Field in Winter

The static chamber alkali-absorption method was used to measure CO2 flux in winter paddy field.The objectives of this study were to：（1） determine the influence of different amount of ditch-buried straw in a paddy-upland rotation system on CO2 flux in winter paddy field;（2）analyze the relation between different amount of straw and CO2 flux;（3） calculate the seasonal CO2 emissions from winter bare paddy field in different amount of straw buried.The results showed that the variation of CO2 flux and seasonal emissions with the amount of straw buried were basically the same,and measured CO2 flux ranged from 51.25 to 84.92 mg·m-2 per hour.However,differences in CO2 flux between different straw amount treatments were not significant.Measured CO2 seasonal emissions ranged from 1591.40 to 1936.12 kg·hm-2,and yet the CO2 flux and seasonal emissions of straw amount treatments were less than the control treatment.The results also indicated that the CO2 flux per unit of straw with the increased amount of straw buried decreased.The measured CO2 flux ranged from 10.63 to 30.69 mg·m-2 per hour,particularly,the difference between 0.5-times treatment and other treatments were significant（P0.05）.