中文摘要：

为揭示烤烟生长期土壤呼吸变化特征及其影响因素，采用田间试验，设置不施肥（CK）、施化肥（NPK）和化肥配施有机肥（NPKOM，有机氮替代30％化学氮）3种处理，采用静态箱-红外CO2法测定土壤呼吸速率，并分析了土壤温度、含水率及根系生物量对土壤呼吸速率的影响。结果表明：①在烤烟大田生长期，不同施肥处理的土壤呼吸速率均呈“M”形变化，两个峰值分别出现在移栽后第81天和第107天，与CK相比，NPK和NPKOM处理可以显著提高烤烟还苗期后的土壤呼吸速率，且两种施肥处理间无显著差异。②烤烟生长期土壤呼吸的变化受土壤温度和根系生物量的影响，土壤呼吸与土壤温度呈显著正相关，5和10cm地温可以分别解释土壤呼吸速率变化的60．4％～67．6％和67．9％～76．1％。施肥和土壤深度增加均能增加土壤呼吸的温度敏感性（Q10）。③在整个大田生长期，土壤呼吸速率随烤烟根系生物量的增大而呈现先增加后减小的趋势，在烤烟生育后期土壤温度对土壤呼吸速率的影响更大。

英文摘要：

In order to investigate the variations and factors influencing soil respiration rate in tobacco field during tobacco growing, a field experiment was conducted with three fertilization treatments, including no fertilizer （CK）, inorganic fertilizer （NPK） and inorganic plus organic fertilizer （NPKOM）. Soil respiration rate was determined by closed chamber-infrared method, and the effects of soil temperature, soil moisture content and tobacco root biomass on soil respiration rate were analyzed. The results showed that： 1） The variation of soil respiration rate presented an M-shape curve during tobacco growing under all three treatments, with two peaks appearing on the 81th and 107th days after tobacco seedling transplanting respectively. Comparing with CK, soil respiration rate was significantly increased by NPK and NPKOM treatments 14 days after tobacco seedling transplanting, and there was no significant difference between NPK and NPKOM treatments. 2） The variation of soil respiration rate was affected by soil temperature and tobacco root biomass during tobacco growing. Soil respiration rate positively correlated to soil temperature to a significant degree, the contribution rates of soil temperature at the depth of 5 and 10 cm to the variation of soil respiration rate were 60.4%-67.6% and 67.9%-76.1%, respectively. Both fertilization and soil depth increased the temperature sensitivity （Q10） of soil respiration. 3） Soil respiration rate increased first then decreased with the increase of tobacco root biomass during the whole tobacco growing period in field, however soil temperature influenced soil respiration rate more significantly at later growing stage.