摘要
The soil nitrogen cycle is primarily driven by microbial communities and provides reactive nitrogen for all organisms.With the increasing impact of human activities and climate change,biogeographical explicit patterns of soil microbial nitrogen-cycling genes and their associations with nitrogen fluxes are still unknown at the global scale.By conducting a global analysis of 1198 soil metagenomic samples,we verified that agricultural land displayed lower microbial richness and diversity values than did the other habitats.We generated a global map of the genetic potential of N cycle processes in soil and revealed that denitrification and dissimilatory nitrate reduction processes are greater in agricultural centers than in non-agricultural areas and are mainly driven by the mean annual temperature and nitrogen fertilizer application.Soil nitrous oxide(N2O)emissions are greater in agricultural land than in other habitats and are mainly driven by nitrogen fertilizer application,which is consistent with the genetic potential of N2O synthesis.Our study improves the theoretical framework for predicting global soil nitrogen cycling potential under complex variables and highlights the influence weight of human activities and climate factors.We strongly emphasize the importance of rationally applying nitrogen fertilizers to balance agricultural production,ecological health and climate change.
基金
supported by the National Natural Science Foundation of China(Grant Nos.42377107,22376187 and 42307158).
