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Grazing cover crops can improve land‐use efficiency and diversification, making agricultural enterprises more resilient to market fluctuations. We investigated how grazing intensity affects cover crop forage responses and cotton (Gossypium hirsutum L.) lint yield. Cover crops were a rye (Secale cereale L.)–oat (Avena sativa L.) mixture managed as follows: no grazing + 34 kg N ha–1 (NG34), no grazing + 90 kg N ha–1 (NG90), heavy grazing (HG), moderate grazing (MG), and light grazing (LG), compared with a no cover crop control. All grazed treatments received 90 kg N ha–1. Average postgrazing herbage mass (HM) for HG, MG, and LG was 520, 1,350, and 2,120 kg dry matter ha–1, respectively. Herbage accumulation (HA) rate was greater for LG than HG, with MG being intermediate. Forage crude protein (CP) and in vitro digestible organic matter (IVDOM) concentrations decreased as the season progressed and were usually greater for HG than MG and LG. Stubble residue before cover crop termination was greatest for NG34 and NG90 in 2018 and 2020, however, in 2019 NG90 had greater stubble residue before termination than NG34 (7540 vs. 6650 kg dry matter ha–1). Heavy grazing resulted in greater weed proportion (17 vs. 6.5%) and lesser soil cover (49 vs. 70%) than nongrazed cover crops. Cotton lint yield was low and unaffected by treatment, reaching a maximum of 520 kg ha–1 in 2019. Although lint yield was not affected by cover crop fertilization or grazing during 3 yr, HG reduced soil cover and increased weed presence. Core Ideas: Herbage accumulation rate was greater for light grazing than heavy grazing.Heavy grazing resulted in lesser soil cover and greater weed proportion than no‐grazing.Forage nutritive value was greater for heavy grazing than light grazing and decreased with maturity.Applying different grazing intensities on cover crops did not affect cotton lint yield. [ABSTRACT FROM AUTHOR]

Replacing N fertilizer with forage legumes may increase sustainability of grazing systems. The objectives were to evaluate herbage and animal responses and to quantify the water footprint associated with beef production in N‐fertilized grass or grass–legume systems during 4 yr under continuous stocking. The three year‐round forage systems were: Grass+N which included N‐fertilized bahiagrass (Paspalum notatum Flüggé) during summer which was overseeded with N‐fertilized cereal rye (Secale cereale L.) and oat (Avena sativa L.) during winter; Grass+Clover included bahiagrass without N fertilizer during summer which was overseeded with rye, oat, and a mixture of clovers (Trifolium spp.) during winter; and Grass+Clover+RP included rhizoma peanut (Arachis glabrata Benth.)–bahiagrass mixture during summer which was overseeded with a similar rye–oat–clover mixture as for Grass+Clover. Clover inclusion improved uniformity of herbage distribution throughout the winter. Including rhizoma peanut increased cattle average daily gain (ADG) by 74% during summer. The ADG in Grass+Clover+RP was 0.61 kg d−1 compared with 0.35 kg d−1 on Grass+N and Grass+Clover. The water footprint during summer was less in Grass+Clover+RP than Grass+Clover (18 and 25 m3 kg−1 bodyweight, respectively). Gain per area (GPA) was similar across all treatments through the year, indicating similar productivity in grass–legume and N‐fertilized grass systems. The N‐fertilizer inputs were reduced from 224 to 34 kg N ha−1 yr−1 in Grass+Clover+RP, compared to Grass+N. Inclusion of rhizoma peanut and clovers contributes to developing sustainable grazing systems with reduced levels of off‐farm inputs. Core Ideas: Inclusion of legumes can offset N‐fertilizer inputs in grazing systems.Beef water footprint was reduced during the warm season with legume inclusion.Legume inclusion enhanced delivery of ecosystem services from grasslands. [ABSTRACT FROM AUTHOR]

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−1d−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. Core Ideas: Nutrient cycling and ecosystem services could increase in grass–legume mixtures.The introduction of legumes could reduce N inputs in beef‐forage systems.The introduction of legumes in grass pastures increase the N available for plant absorption. [ABSTRACT FROM AUTHOR]

Plant litter deposition and decomposition play important roles in grassland nutrient cycling. The objective was to evaluate plant litter responses and estimate the N returns via plant litter in contrasting grazing systems, since legume inclusion is hypothesized to result in similar quantities of N return compared with N‐fertilized grass systems. Systems were (a) N‐fertilized bahiagrass (Paspalum notatum Flüggé) during summer with a mixture of N‐fertilized cereal rye (Secale cereale L.) and oat (Avena sativa L.) during winter (Grass+N); (b) bahiagrass (no N fertilizer) during summer and a rye–oat–clovers (Trifolium spp.) mixture + N in winter (Grass+Clover); and (c) bahiagrass (no N fertilizer in summer) with strip‐planted rhizoma peanut (Arachis glabrata Benth.) during summer with a rye–oat–clovers mixture + N during winter (Grass+CL+RP). Litter mass was greatest for Grass+N during October (4,430 kg organic matter [OM] ha−1) and least for Grass+CL+RP in June (490 kg OM ha−1). Litter N concentrations were greatest in Grass+N (16 g kg−1), with similar N concentration for Grass+Clover and Grass+CL+RP litter (14 g kg−1). Contribution of C3 species to litter mass increased from May to July but decreased thereafter. Overall, there was a net return of 47 kg N ha−1 yr−1 via litter across the three systems, and litter decomposition was similar in the three systems. Inclusion of forage legumes during cool and warm seasons in grazing systems has the potential to return similar amounts of N through plant litter deposition as grasses receiving moderate levels of N fertilizer. [ABSTRACT FROM AUTHOR]