修剪频率对混播草坪土壤呼吸特征的影响

Effect of Mowing Frequency on Characteristics of Soil Respiration of Mixed Turfgrass

以草地早熟禾(Poa pretensis)和高羊茅(Festuca arundinacea)混播草坪为研究对象,采用开路式土壤碳通量测量系统Li-8100对不同修剪频率下草坪的土壤呼吸昼夜变化特征进行研究,旨在探讨修剪对城市草坪土壤呼吸特征的影响。结果表明:草坪在1周修剪1次、2周修剪1次和常规修剪(对照)这3种情况下,其土壤呼吸速率昼夜变化均呈单峰曲线模式,且3种情况下草坪土壤呼吸速率日最高值均出现在12:00-14:00,而日最低值出现的时间不一;从草坪土壤日呼吸总量来看,6月与7月草坪在1周修剪1次处理、2周修剪1次处理和对照之间差异均不显著,8月草坪在1周修剪1次处理下与对照之间差异不显著,而两者与草坪2周修剪1次的处理之间差异显著(P<0.05);从整体来看,3种情况下草坪的土壤呼吸速率均与5cm土层地温成显著正相关(P<0.05),与其他温度指标的相关性因不同月份和不同处理而不同,而草坪土壤呼吸的Q10值的大小基本上都随着土层深度增加而增加。

Mixed turfgrass consisting of Poa pretensis and tall fescue in front of the Herbage Seed Pavilion at Chinese Agricultural University was researched.Diurnal dynamic characteristic of turfgrass soil respiration rate among different mowing frequencies was measured using Li-8100 system.Results showed that the diurnal variation of soil respiration rate presented a monopeak curve for mowing once a week,mowing once every two weeks and common practice（control）.The maximum soil respiration rate appeared at 12：00-14：00 for all treatments,whereas the minimum soil respiration rate appears inconsistent for all treatments.Annual total soil respiration output of turfgrass had no significant difference among all treatments in June and July.Annual total soil respiration output of turfgrass mowed once every two weeks had significant difference in August compared with that of turfgrass when mowed once a week and the control.There was no significant difference between the turfgrass mowed once a week and control.There was a significant positive correlation as a whole between soil respiration rates and soil temperatures at five cm depth in all treatments.However,the correlation between soil respiration rates and other temperature indicators varied for different months and different treatments.Q10 value of turfgrass soil respiration was increased with soil depth increasing.