N-fertiliser application or legume integration enhances N cycling in tropical pastures

Understanding the effects of N application or the introduction of a legume on N cycling is critical for achieving productive and sustainable grassland systems. This 2-year study assessed the N cycling of three pasture treatments: (1) mixed Marandu palisadegrass ( Brachiaria brizantha ) and forage peanut ( Arachis pintoi ) without N fertiliser (GRASS + LEGUME); (2) monoculture Marandu palisadegrass fertilised with 150 kg N ha −1 year −1 (GRASS + N); and (3) monoculture Marandu palisadegrass without N fertiliser (GRASS). Continuous stocking was used with a target canopy height of 0.20 to 0.25 m. Litter responses, forage and N intake, N livestock excretion and N cycling were measured. Existing litter and litter deposition rate were greatest in GRASS pasture (3030 and 84.3 vs. 2140 kg ha −1 and 64.8 kg OM ha −1 d −1 ; average of GRASS + N and GRASS + LEGUME pastures, respectively; P