Surface Soil Properties Influence Carbon Oxide Pulses After Precipitation Events in a Semiarid Vineyard Under Conventional Tillage and Cover Crops  

作　　者：Fernando PEREGRINA 

机构地区：[1]CSIC-CAR-UR, Instituto de Ciencias de la Vid y el Vino(ICVV)

出　　处：《Pedosphere》2016年第4期499-509,共11页土壤圈（英文版）

基　　金：supported by the Spanish Ministry of Science, INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria), Spain;European Social Fund (INIA-RTA 2009-00101-00-00);the INIA and European Social Fund for his postdoctoral grant

摘　　要：In semiarid regions of the Mediterranean basin, a rainfall event can induce a respiratory pulse that releases a large amount of soil carbon dioxide （CO2） into the atmosphere; this pulse can significantly contribute to the annual ecosystem carbon （C） balance. The impacts of conventional tillage and two different cover crops, resident vegetation and Bromus catharticus L., on soil CO2 effiux were evaluated in a Vitis vinifera L. vineyard in La Rioja, Spain. Soil CO2 efflux, gravimetric water content, and temperature were monitored at a depth of 0-5 cm after rainfall precipitation events approximately every 10 d in the period from May 17 to July 27, 2012, during which the cover crops had withered. Additionally, on June 10, 2012, soil organic C, microbial biomass C, and I^-glucosidase activity were determined at soil depths of 0-2.5, 2.5-5, 5-15, and 15-25 cm. The results show that pulses of soil CO2 were related to the increase in soil water content following precipitation events. Compared to the conventional tillage treatment, both cover crop treatments had higher soil CO2 efflux after precipitation events. Both cover crop treatments had higher soil organic C, microbial biomass C, and β-glucosidase activity at the soil surface （0-2.5 cm） than the conventional tillage treatment. Each pulse of CO2 was related to the surface soil properties. Thus, this study suggests that the enhancement of soil organic C and microbiological properties at the soil surface under cover crops may increase soil CO2 efflux relative to conventional tillage immediately after precipitation events during the dry season.In semiarid regions of the Mediterranean basin, a rainfall event can induce a respiratory pulse that releases a large amount of soil carbon dioxide(CO_2) into the atmosphere; this pulse can significantly contribute to the annual ecosystem carbon(C) balance.The impacts of conventional tillage and two different cover crops, resident vegetation and Bromus catharticus L., on soil CO_2 efflux were evaluated in a Vitis vinifera L. vineyard in La Rioja, Spain. Soil CO_2 efflux, gravimetric water content, and temperature were monitored at a depth of 0–5 cm after rainfall precipitation events approximately every 10 d in the period from May 17 to July 27, 2012,during which the cover crops had withered. Additionally, on June 10, 2012, soil organic C, microbial biomass C, and β-glucosidase activity were determined at soil depths of 0–2.5, 2.5–5, 5–15, and 15–25 cm. The results show that pulses of soil CO_2 were related to the increase in soil water content following precipitation events. Compared to the conventional tillage treatment, both cover crop treatments had higher soil CO_2 efflux after precipitation events. Both cover crop treatments had higher soil organic C, microbial biomass C, and β-glucosidase activity at the soil surface(0–2.5 cm) than the conventional tillage treatment. Each pulse of CO_2 was related to the surface soil properties. Thus, this study suggests that the enhancement of soil organic C and microbiological properties at the soil surface under cover crops may increase soil CO_2 efflux relative to conventional tillage immediately after precipitation events during the dry season.

关 键 词：microbial biomass C β-glucosidase activity soil CO2 effiux soil water content soil temperature 

分 类 号：S663.1[农业科学—果树学] S151.9[农业科学—园艺学]