【作者】 陈述悦；

【导师】 陆佩玲； 李俊；

【作者基本信息】 北京林业大学 ， 生态学， 2004， 硕士

【摘要】 2002年10月-2003年10月在中科院山东禹城综合试验站采用静态箱／气相色谱（GC）法测定了华北平原典型农田的土壤呼吸速率。结果表明：冬小麦田土壤呼吸速率日变化呈单峰曲线，最高峰出现在中午13点左右，最低点在凌晨4点左右；夏玉米田土壤呼吸速率日变化呈双峰曲线，峰值一般出现在11：00～15：00和次日1：00～7：00，谷值出现在22：00～1：00；棉田土壤呼吸速率日变化较复杂，有时呈单峰曲线，最高峰出现在中午13点左右，最低点在凌晨4点左右；有时呈双峰曲线，峰值一般出现在15：00～17：00和次日22：00～1：00，谷值出现在凌晨4点左右；冬小麦田生长季土壤呼吸速率平均冬季较低，夏季较高，与地温的季节变化趋势基本一致；夏玉米田土壤呼吸速率的季节动态基本上呈单峰曲线；棉田土壤呼吸季节变化分为休闲期和种植作物期，土壤呼吸速率平均冬季较低，夏季较高，与地温的季节变化趋势基本一致；尽管随氮肥用量增加土壤呼吸增强，但增幅不大，秸秆还田处理的土壤呼吸作用明显高于秸秆不还田处理和氮肥处理（冬小麦田）；土壤呼吸同地温存在着显著的指数关系，其中5 cm地温同土壤呼吸相关性最好，不同处理，不同深度土层具有不同的Q₁₀值，Q₉10)值随土壤的性状、地温测量的深度和微生物活动的土层深度变化而改变，它本身是温度的函数，随着温度的升高，Q₁₀值呈下降趋势；土壤呼吸与土壤水分的关系较弱，没有表现出明显的规律性；冬小麦平均净光合速率与土壤呼吸速率有相似的变化趋势，从返青到腊熟，冬小麦田表现为CO₂的汇。更多还原

【Abstract】 Experimental studies were done at the Yucheng comprehensive experimental station of the Chinese Academy of Sciences during 2002-2003. Respiration of a pulverous sandstone soil was studied under cultivation of winter wheat, summer maize and cotton over a growth season and under fallow. The results indicated that diurnal variation of soil respiration rate showed a single peak in farmlands of winter wheat, double peak in farmlands of summer maize, both single peak and double peak in farmlands of cotton. In the winter wheat fields, soil respiration rate reached the highest at about 13 o’clock, and the lowest at about 4 o’clock in the early morning, and in the summer maize fields, soil respiration rate reached the highest at about 11:00~15:00 and 1:00~7:00 in the morrow, and the lowest at about 22:00-1:00, and in the cotton fields, soil respiration rate reached the highest at about 13 o’clock, and the lowest at about 4 o’clock in the early morning when it showed a single peak, and when it showed a double peak, the soil respiration rate reached the highest at about 15:00-17:00 and 22:00-1:00 in the morrow, and the lowest at about 4 o’clock in the early morning. The soil respiration rate of winter wheat, summer maize and cotton, showing a similar seasonal variation tendency with soil temperature. Among all treatments, the straw manure had the most distinct soil respiration, though soil respiration also increased slightly with increasing nitrogenous fertilizer. Soil respiration increased exponentially with increasing soil temperature, and the correlation of soil temperature at the depth of 5 cm was the best. This relationship was usually described with the Q10 model, which represented the sensitivity of soil respiration to temperature. Q10 was not a fixed value, it varied with the depth at which the temperature was measured and the depth of the active soil layer and soil temperature. At same time, the Q10 value decreased with increased soil temperature. Soil water content was another important factor influencing the soil respiration rate, but in this region, the relationship between soil respiration and soil moisture was poor, and no distinct rules was shown. Average net photosynthesis rate of winter wheat had a close relation with soil respiration rate, differences between them showed that photosynthetic uptake of CO2 was beyond emission of soil respiration during the period from return green to mature, and the farmland of winter wheat was a sink of CO2.更多还原