Nitrogen dynamics of urine in pasture, 2: Fate of cattle urine-N labelled with 15N-urea in bahiagrass (Paspalum notatum Fluegge) pasture

15N-labelled cattle urine was applied to small plots (20 cm diameter enclosed in polyvinyl chloride cylinders, 35 cm deep) in bahiagrass (Paspalum notatum flugge) pasture on 4 June, 24 July and 14 October 1991, to trace the fate of urine-N in the soil-plant system. After one year, recovery of 15N in measured components was similar for each application date. Between 27.5-35.4% of the applied 15N was recovered in the plant parts with a further 8.8-12.2% remaining in the soil and 1.3-1.6% in litter (both above and below ground). Of the 15N applied, 53.6-59.9% was unaccounted for in the soil-plant system after one year. It was suggested that a bahiagrass pasture in this region (south Kyushu) was a open system for the nitrogen cycle, allowing for above 50% losses of urinary N from soil-plant system