Nitric and nitrous oxide fluxes from intensifying crop agriculture in the seasonally dry tropical Amazon–Cerrado border region

Abstract Rapid expansion and intensification of crop agriculture in the tropics may accelerate ecosystem losses of reactive nitrogen (N). We quantified emissions of nitric oxide (NO) and nitrous oxide (N2O) in forest, single‐cropped soybean [Glycine max (L.) Merr.], and N‐fertilized double‐cropped soybean–maize (Zea mays L.) at three N fertilizer levels within the largest area of recent cropland expansion on earth, in the Amazon and Cerrado biomes in Brazil. The NO emissions were 2.1 kg N ha‒1 yr‒1 in forest, 0.6 kg N ha‒1 yr‒1 in soybean, and 1.3 kg N ha‒1 yr‒1 in soybean–maize. The N2O fluxes were