Earthworm cast as nitrifiers' paradise in terrestrial ecosystems: a hot spot of N2O production

• 作 者: TakamaruKobayashi[1]KeisukeKoba[1]NobuhiroKaneko[2]MuneokiYoh[1]
• 机 构: Tokyo University of Agriculture and Technology,Tokyo 183-8509,Japan
• 出 处: International Symposium on Forest Soils(2013年森林土壤国际研讨会)
• 发表日期: 2013年期

　　Soil fauna can be an agent to create a hot spot of N2O production in soil but its quantitative importance has been poorly understood. Here, we studied total dose of N2O production and the nitrogen cycling in casts from earthworm. Casts in different size collected from earthworms were incubated for two weeks till the processes virtually ceased.Overall, large quantity ofNH4+ initially contained in fresh casts was totally oxidized to NO3- via nitrification. which was principally responsible for active N2O production during this period. Denitrification also took place in casts, leading to N loss and partly contributing to N2O production, especially in larger casts (>8mm). N2O production was 28-fold t0 229-fold intensive in casts relative to the soil. According to our preliminary estimate, casts from earthworm contribute to about 7%of the global N2O flux from natural soils.