玉米秸秆覆盖免耕对土壤呼吸的影响

Effect of no-tillage with maize straw mulching on soil respiration

土壤呼吸是大气CO2的重要来源,而我国华北平原玉米秸秆覆盖免耕对土壤呼吸的影响的研究报道较少。该文的研究目的主要在于揭示玉米秸秆覆盖免耕对土壤呼吸的影响,为农作措施对碳循环的影响的研究提供理论依据。覆盖免耕试验结果表明,玉米秸秆覆盖免耕土壤CO2全年平均释放量为13.2g·m-2·d-1,分别比还翻处理和清翻处理增加8.38%和27.6%。所有测定时间中,除去2007年4月24日外,在其余取样时间里处理之间CO2释放量均呈差异显著。不同处理土壤呼吸均表现出显著的季节性动态变化,7月是全年的呼吸高峰期,覆盖免耕在5月多出一次高峰期。玉米秸秆覆盖免耕全年土壤呼吸的最低峰值比最高峰值降低77.1%,显著高于清茬翻耕和还田翻耕,表明玉米秸秆覆盖免耕土壤呼吸季节性变化较为强烈。

The carbon dioxide produced by soil respiration is one of important sources of atmospheric CO2, which always received much more attention as indicators of some soil properties. Research about effect of zero-tillage with maize straw mulching （NSM） on soil respiration was rarely reported in North China, so the purpose of the study is to make it clear to provide theoretical basis for the further investigation of influence of agricultural management on carbon cycling. The results of the experiment showed that the annual release content of CO2 from soil in treatment of NSM on average was 13.2 g·m^-2·d^-1 and rised by 8.38% and 27.6% compared with tillage with maize straw incorporation （TSI） and tillage with no maize straw return （TNS） respectively. Soil respiration had significant difference between treatments in all the investigation time except for 24 Apr. 2007. Significant seasonal dynamic change of soil respiration was found in all treatments. Three tests all had their soil respiration peak in July, nevertheless there was more one in NSM in May. The lowest value of releasing of CO2 decreased by 77.1% compared with the highest value in NSM all over one year, which was significant higher than other two treatments and indicated that soil respiration changed greatly.