Warm‐climate grasslands are often N limited. Legume litter decomposition can contribute significantly to N input in grazing systems, but its contribution depends on litter deposition, decomposition, and chemical composition. We evaluated these responses for 2 yr in unfertilized (BG) and fertilized (BGN; 50 kg N ha−1) bahiagrass (Paspalum notatum Flügge) monocultures and in mixed swards of bahiagrass plus the legume rhizoma peanut (Arachis glabrata Benth.). Legume–grass mixture litter had greater initial N concentration (26 g N kg−1 organic matter [OM]) and lower C/N ratio (22) than BG and BGN, which did not differ from each other (18 g N kg−1 OM, C/N ratio of 31). Litter biomass relative decay rate was greater for mixtures than for bahiagrass monocultures. As a result, less biomass and N remained at the end of incubation in mixtures (62 and 76%, respectively) than in monocultures (69 and 80%, respectively). Litter deposition rate was similar across treatments, but faster decomposition and greater N concentration for legume–grass mixtures resulted in larger litter N release than in monocultures (44 and 26 kg ha−1, respectively). At the end of incubation, remaining litter biomass and remaining N decreased with increasing litter legume proportion, whereas litter N concentration and litter decay rate increased. Results indicate that legume–grass mixtures are an alternative to N fertilizer for increasing N cycling through plant litter in grasslands, and although litter deposition rates were similar across treatments, increasing legume proportion in mixtures is likely to be associated with greater litter N release.

Forage kochia (Bassia prostrata L.) can persist in disturbed areas and provide high‐quality forage even during fall and winter months. However, information is needed on the effect of planting time and subsequent environmental conditions on forage kochia establishment. A field study was initiated in 2014 in Wyoming to determine the optimum planting time for successful forage kochia establishment and examine its performance in seeded mixtures with perennial cool‐season grasses in areas dominated by annual weeds. The experiment was carried out using split‐plot in a randomized complete block design with four replications. The main plots consisted of three planting times (late winter, early spring and summer), and subplots included eight seeding mixture treatments. Species included in mixtures were forage kochia, four native grasses and two nonnative grasses. The summer (May) planting failed completely, and early spring (April) planting resulted in greater plant density for forage kochia and grasses than late winter (March) planting. Although, forage kochia monoculture had greater forage kochia density than other treatments, forage kochia stands were satisfactory when seeded in mixtures with perennial grasses. By the year after planting, plant density of forage kochia and grasses was reduced to about one‐third of 2014 density. During initial establishment stage, it is thought that forage kochia and perennial grasses were affected by dense cover of annual weeds. However, greater plant density was observed for April compared to March plantings, and forage kochia monoculture had good stands despite dense stands of annual weeds, even in 2015. The results suggest that successful establishment of forage kochia is possible when it is planted in early spring under conditions of this study. However, monitoring stands the following years is needed to determine the persistence and forage production of different seeding mixtures of forage kochia and perennial grasses.

Rhizoma peanut (RP, Arachis glabrata Benth.) is an important perennial forage legume, but its adoption can be limited by relatively slow establishment. Genotype and temperature after planting of rhizomes likely affect partitioning of stored and new photoassimilates, but their impact on establishment rate is not known. To assess these relationships, planting date and RP entry effects were measured on biomass partitioning and growth responses. Treatments were all combinations of two planting dates (spring and summer) and four entries (‘Florigraze’, ‘UF Peace’, ‘UF Tito’, and the germplasm Ecoturf) replicated four times, with new plots planted in each of 2 yr. Spring‐planted Florigraze outperformed UF Peace in shoot count, shoot biomass, and root‐rhizome biomass through much of the year of planting. When planted in summer, UF Tito and UF Peace generally had earlier and greater shoot emergence, lesser root‐rhizome/shoot ratio, taller canopy height, and lesser leaf/stem ratio than Ecoturf or Florigraze. Across years, shoot biomass in the year after planting was greater for UF Peace and UF Tito than for Ecoturf and Florigraze when planted in summer (490, 387, 265, and 157 g m−2, respectively) and greater for UF Peace than Ecoturf or Florigraze planted in spring (349, 243, and 201 g m−2, respectively). UF Tito and UF Peace had greater shoot biomass in the year after planting for summer than for spring plantings, but there was no season effect for Ecoturf and Florigraze. Summer planting favored rapid establishment of upright cultivars UF Tito and UF Peace, but Ecoturf and Florigraze were less affected by season.

Rhizoma peanut (RP; Arachis glabrata Benth.) is an important species for hay production in the U.S. Gulf Coast region; however, frequent summer rains and high humidity often preclude optimal harvest intervals. Extended regrowth periods are common on‐farm but data are limited assessing their impact on plant responses. The objective was to compare above‐ and belowground responses of 14 RP entries to defoliation frequency during 3 yr. Frequencies were one (1×) and two (2×) harvests per year, reflecting common producer practice. Annual herbage accumulation (HA) was approximately twice as great for 2× than 1× (10.5 vs. 5.4 Mg ha−1 yr−1, respectively). An exception was experimental line Beta for which HA did not differ between frequencies, perhaps because of Beta's greater disease tolerance that minimized leaf shedding. The 2× frequency also had greater herbage crude protein concentration than 1× (150 and 125 g kg−1, respectively). Reductions in HA and nutritive value for 1× vs. 2× were generally greatest for upright‐growing entries. Plots cut once per year had 54% more root–rhizome mass than those cut twice (8.5 vs 5.5 Mg ha−1, respectively) but defoliation frequency did not affect root–rhizome total nonstructural carbohydrate (TNC) concentration. Results indicated RP hay producers should harvest both summer and fall (2×) at minimum. If rhizomes are to be dug for subsequent vegetative propagation, defoliation should be limited to once annually to avoid reduction in root–rhizome mass.

The ingrowth core method for measuring root accumulation has several advantages over sequential soil cores or mini‐rhizotrons. However, current ingrowth core designs are not well suited for use with rhizomatous perennial forage species or when defoliation occurs during the measurement period. Our objective was to develop a modified ingrowth core device and to evaluate its use for measuring root‐rhizome accumulation of a rhizomatous perennial forage in a hay management context. The modified ingrowth cores were constructed of 4‐mm polyester mesh surrounding a 7.5‐cm diameter cylinder constructed of cage wire. Field testing of the core design involved placing three ingrowth cores in each of four replicates of six treatments arranged in a randomized complete block design. Treatments consisted of six rhizoma peanut (Arachis glabrata Benth.) entries, and they were evaluated during 2017 and 2018. The ingrowth core design facilitated ease of placement, maintenance of core structural integrity throughout 100‐d deployment periods, rapid location of cores using a metal detector at the end of deployment periods, and precision to detect differences among treatments. We conclude that this modified ingrowth core design is well suited for measuring root‐rhizome accumulation rate of perennial forage species. Core Ideas Root or root‐rhizome biomass is the dominant C supply to grassland soils. There is little information on root‐rhizome accumulation rates under perennial forage crops. A modified root ingrowth core device was developed and tested in a field study. The modified core maintained structural integrity and successfully detected differences among treatments.