Nutrient cycling via livestock excreta is an important grassland ecosystem service.This study was conducted in 2016 and 2017 and determined nutrient excretion from cattle grazing three systems: (a) N-fertilized bahiagrass (Paspalum notatum Flüggé) overseeded with rye (Secale cereale L.) and oat (Avena sativa L.) during winter (Grass+N), (b) unfertilized bahiagrass overseeded with rye-oat-clover (Trifolium sp.) mixture (Grass+clover), and (c) rhizoma peanut (Arachis glabrata Benth.)bahiagrass mixture overseeded with a rye-oat-clover mixture (Grass+CL+RP). Urinary volume excreted in the warm season ranged from 122 to 182 L ha −1 d −1 , more than double that in the cool season (56-70 L ha −1 d −1 ). Urinary N concentration during the warm season was greater in Grass+CL+RP compared with Grass+N (4.4 vs.3.1 g kg −1 , respectively). In addition, fecal dry matter and organic matter output was greater for Grass+N than for steers grazing Grass+CL+RP during the warm season (3.8 and 3.2 vs. 2.8 and 2.2 kg hd −1 d −1 , respectively). Total annual feces excretion concentrations of P, K, Mg, and N were greater in the Grass+N than in Grass+CL+RP system. The introduction of legumes increased the proportion of N returning via urine. However, when summed across seasons, total N excretion (feces and urine) was greater in Grass+N than in Grass+CL+RP (89 vs. 71 kg ha −1 yr −1 ), mainly due to the greater stocking rate in the former. Grass-legume systems receiving 34 kg N ha −1 yr −1 recycled 80% of the N recycled in the grass system receiving 224 kg N ha −1 yr −1 , indicating the potential of forage legumes to add N to grasslands.In grazing systems, nutrient cycling is a complex network of interactions between plant growth, type of livestock grazing, grazing intensity, and soil fauna and flora (Burns & Sollenberger, 2001). Nutrients such as C, N, P, and S reside temporarily in various reservoirs or different pools in the Abbreviations: DM, dry matter; IVDOM, in vitro digestible organic matter; OM, organic matterThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.