本文根据NaOH溶液吸收CO2的方法,对西安南郊和陕北长武地区土壤CO2释放量进行了昼夜观测。观测结果表明,不同地区土壤CO2释放量存在差异,气候偏冷偏干地区土壤CO2释放量较小,气候偏热偏湿地区土壤CO2释放量较大。陕北长武土壤CO2释放量变化再次证明,从当日早晨至次日早晨,CO2释放量具有由低变高再变低的规律;CO2释放量相对于大气温度的日变化具有滞后性,滞后时间为4～6小时;土壤CO2释放量白天较少,夜间较多;CO2释放量变化显示,在土层深厚的地区,土壤微生物夜间活动强度总体应比白天大。 According to the method of absorbing CO2 by NaOH solution, this paper studied the day and night of soil CO2 emission from the southern suburb of Xi’an and Changwu of northern Shaanxi. The results showed that there was a difference in soil CO2 emission in different areas. Soil CO2 emission was relatively small in the areas with colder and colder climates, and larger in the areas with partial climatic warming. The change of soil CO2 emission in Changwu County in northern Shaanxi proved once again that from the morning of the next morning to the next morning, the CO2 emission had the law of low to high and then low; the diurnal variation of CO2 emission relative to the atmospheric temperature lagged, and the lag time For 4 to 6 hours; soil CO2 emission less during the day and night more; changes in the amount of CO2 released in the deep soil areas, soil microorganisms at night activity intensity should be larger than at daytime.