Effect of Elevated Carbon Dioxide on Nitrogen Dynamics and Greenhouse Gas Emissions in Grain Crop and Legume Pasture Systems: FACE Experiments and a Meta-Analysis

Abstract

By 2070, atmospheric carbon dioxide concentration [CO2] is expected to be double that observed in 1950. In this higher [CO2] world, the sustainability of global crop production may be in jeopardy unless current nitrogen (N) management strategies are changed because of potential interactions between elevated atmospheric [CO2] and soil N dynamics. However, these interactions are poorly understood especially in semi-arid cropping systems. In this paper, experimental results are presented on the effects of elevated [CO2] on crop N demand, fertilizer N recovery, symbiotic N2 fixation and greenhouse gas emissions from cropping systems in southern Australia and northern China using free-air CO2 enr..