Interaction between soil and fertiliser nitrogen drives plant nitrogen uptake and nitrous oxide (N2O) emissions in tropical sugarcane systems

Summary

Abstract Aims High nitrogen (N) fertiliser inputs in intensive sugarcane systems drive productivity but also significant emissions of nitrous oxide (N 2 O), a potent greenhouse gas. Fertiliser and soil N availability for both plant N uptake and N 2 O emissions across different N rates remain unknown, hindering efficient N management. This study investigated the contribution of fertiliser and soil N and their interaction to plant N uptake and N 2 O emissions in two intensively managed tropical sugarcane systems. Methods High temporal resolution N 2 O measurements were combined with 15 N recoveries across four N fertiliser rates, (100, 150, 200 and 250 kg N ha − 1 ) in soil, plant and N 2 O emissions. Results Cumulative N 2 O emissions ranged from 0.3 to 4.1 kg N ha − 1 , corresponding to em