Nutrient excretion from cattle grazing nitrogen‐fertilized grass or grass–legume pastures

Nutrient cycling via livestock excreta is an important grassland ecosystem service. This study was conducted in 2016 and 2017 determined nutrient excretion from cattle grazing three systems: (a) N-fertilized bahiagrass (Paspalum notatum Flüggé) overseeded with rye (Secale cereale L.) oat (Avena sativa during winter (Grass+N), (b) unfertilized rye–oat–clover (Trifolium sp.) mixture (Grass+clover), (c) rhizoma peanut (Arachis glabrata Benth.)–bahiagrass a (Grass+CL+RP). Urinary volume excreted the warm season ranged 122 to 182 L ha−1d−1, more than double that cool (56–70 ha−1 d−1). N concentration greater Grass+CL+RP compared Grass+N (4.4 vs. 3.1 g kg−1, respectively). In addition, fecal dry matter organic output for steers (3.8 3.2 2.8 2.2 kg hd−1 d−1, Total annual feces concentrations of P, K, Mg, were system. The introduction legumes increased proportion returning urine. However, when summed across seasons, total (feces urine) (89 71 yr−1), mainly due stocking rate former. Grass–legume systems receiving 34 yr−1 recycled 80% grass system 224 yr−1, indicating potential forage add grasslands.