重庆丘陵山区石灰性黄壤呼吸特征及影响因素

Characteristics and affecting factors of calcareous yellow soil respiration in hilly fields in Chongqing

采用静态暗箱-二氧化碳红外分析仪法研究了重庆丘陵山区石灰性黄壤土壤呼吸特征及影响因素。结果表明，土壤呼吸速率呈现季节性动态变化特征，冬季较低，夏季较高，与地温的季节动态变化基本一致；土壤呼吸与地温之间呈指数关系，其中与5cm地温的相关性最好；不同土层、不同处理的Q10值不同，变化范围为1，67．2．69。不同田间管理措施对土壤呼吸速率有明显影响，表现为施肥土壤）未施肥处理。种植作物土壤）裸地；化肥使种植作物土壤的年平均呼吸速率增加70．8％，化肥、粪肥共同作用增加129％；与裸地相比，单种作物不施肥不能显著增加土壤CO2排放。裸地春、秋、冬季的土壤呼吸速率与土壤水分呈直线关系，决定系数R^2=0．414，P〈0．01。在夏季．种植作物未施肥和施化肥处理两者也呈直线关系。R^2分别为0.5361和0.4261（P〈0.05），其他季节两者来表现出明显的规律性。

The given article is inclined to present the authors＇ experimental measurements with the soll respiration rate and its characteristics and influencing factors with the calcareous yellow soil in the hilly fields in Chongqing context. The whole study is designed in 4 kinds of treatment known as PCFM （planting and controlled-using manure ＋ fertilizer）, PCF （planting and controlled-using fertilizer）, PNF （planting and none fertilizer） and NPNF （no planting and none fertilizer）. The plant to be experimented with is cabbage. The measurements we conducted proceeded in three times a month from 9：00 am to 12：00 am in planting seasons by means of a static-dark-chamber/ INFRARED CO2 CONTROLLER. The results of our experimental measurements indicate that the soil respiration rate proves to be a similar seasonal dynamic variation tendency with soil temperatures. It would increase exponentially with the increase of soil temperatures and be correlated with the soil temperatures optimally at the depth of 5 cm. Thus, the correlation can be described in a Q10 model, which varies from 1.67 to 2.69. To be sure, the four treatments have different Q10 values seemingly known exponentially ascending as Qlo （PCFM） 〈 Q10（PCF） 〈 Q10（PNF） 〈 Q10（NPNF） . The fertilizer and manure prove to make the soil respiration increase noticeably in every treatment, though the variation of the extent or value of increase remains inaccurate for the time being. Compared with the planting-nofertilizer treatment, fertilizer proves helpful to make the soil respiration rate increase by 70.8% and fertilizer-manure would make it increase by 129%. When compared with bare soil, planting but no fertilizer application didn＇t seem to show remarkable increase of CO2 emission flux. Furthermore, it can also be proved that the increase of the soil respiration rate takes a linear form with the increase of soil moisture in summer in PNF and PCF treatment, but with little or no increase in the bare soil during the rest seasons but summer.