果园土壤有机碳及呼吸速率对豆科和禾本科草类的差异反应

Responses of Soil Organic Carbon and Respiration Rates to Legumes and Gramineous Grasses in Orchards

在行间长期(连续6年)种植豆科植物毛苕子和禾本科植物黑麦草的苹果园,调查土壤不同深度的有机碳组分和表层土壤呼吸速率日变化。结果表明:间作2种植物后,行间土壤0—20,20—40cm土层总有机碳(TOC)、轻质有机碳(LFOC)、可溶性有机碳(DOC)、颗粒有机碳(POC)、易氧化有机碳(ROC)和微生物生物量碳(MBC)含量均显著提高;在40—60cm土层,仅DOC含量明显提高;0—20cm土层的TOC和全部有机碳组分及20—40cm土层的TOC、DOC、POC和ROC的含量在种植毛苕子后均明显高于种植黑麦草。TOC与LFOC、TOC与POC、DOC与LFOC、DOC与MBC、DOC与ROC、MBC与ROC、ROC与POC、LFOC与ROC之间均呈显著正相关,土壤呼吸速率与LFOC、DOC、MBC和ROC之间也呈显著正相关。种植2种草类均显著提高土壤呼吸速率,并使呼吸速率日变化峰型更突出,其中毛苕子的作用效果比黑麦草更显著。

The gramineous Lolium perenne L.and leguminous Vicia villosa Roth had been intercropped in apple orchard for6years.The organic carbon fractions in different depth of soil and the daily variation of the respiration rate in surface soil were investigated in the orchard.The results showed that the L.perenne and V.villosa intercropped significantly increased the content of total organic carbon(TOC)and the content of organic carbon components,such as light organic carbon(LFOC),dissolved organic carbon(DOC),particulate organic carbon(POC),readily oxidation of organic carbon(ROC)and microbial biomass carbon(MBC),in0-20cm and20-40cm soil layer in apple orchard,and the increase degree caused by V.villosa both was higher than that by L.perenne.In40-60cm soil layer,only soil DOC content was increased by intercropping.The content of all organic carbon fractions in0-20cm layer soil and TOC,DOC,POC and ROC in20-40cm layer soil in the orchard intercropped V.villosa were significantly higher than that in the orchard intercropped L.perenne.There were positive relationships between TOC and LFOC,TOC and POC,DOC and LFOC,DOC and MBC,DOC and ROC,MBC and ROC,ROC and POC,and between LFOC and ROC.The rate of soil respiration had the positive relationships with LFOC,DOC,MBC,and ROC.The rate of soil respiration was increased significantly by intercropping L.perenne and and V.villosa;the characteristics of the peak type were more obvious under the intercropping condition during the day,while the effect of intercropping V.villosa was better than that of L.perenne.