Tillage and nitrogen fertilization enhanced belowground carbon allocation and plant nitrogen uptake in a semi-arid canola crop-soil system.

Carbon (C) and nitrogen (N) allocation and assimilation are coupled processes, likely influencing C accumulation, N use efficiency and plant productivity in agro-ecosystems. However, dynamics and responses of these processes to management practices in semi-arid agro-ecosystems are poorly understood. A field-based CO and urea-N pulse labelling experiment was conducted to track how C and N allocation and assimilation during canola growth from flowering to maturity were affected by short-term (2-year) tillage (T) and no-till (NT) with or without 100 kg urea-N ha (T-0, T-100, NT-0, NT-100) on a Luvisol in an Australian semi-arid region.