Improving bermudagrass in the Southeastern United States with alfalfa as an alternative nitrogen source in grazing systems

Abstract

Background Bermudagrass (Cynodon spp.) is one of the most common perennial warm‐season forages grown in the Southeastern United States. The incorporation of alfalfa (Medicago sativa) into bermudagrass pastures could serve as an alternative source of nitrogen (N) while also improving the nutritive value of the forage base. Methods A 2‐year grazing evaluation arranged in a randomized complete block design was conducted from May to September 2018 (Year 1) and May–August 2019 (Year 2) in Tifton, GA, USA. The objective was to compare the production of alfalfa–bermudagrass mixed pastures (BGA) with bermudagrass monoculture pastures with (BGN) or without (BG) the application of synthetic nitrogen on forage production and stocker cattle performance. Results Differences were observed for average daily gain (p = 0.10), gain per hectare (p = 0.02) and stocking rate (p = 0.01), in that BGA was greatest compared to BGN and BG, which did not differ from each other. Furthermore, BGA had increased forage crude protein (p = 0.01) and total digestible nutrients (p = 0.01) compared to BGN and BG. Finally, BGA provided the greatest economic return per hectare compared to BG or BGN. Conclusions These data illustrate improved animal performance and forage nutritive value using alfalfa–bermudagrass systems and offer a viable option for producers seeking alternatives to synthetic N sources for bermudagrass pastures in the Southeastern United States.

Understanding the agronomic impacts of defoliation strategies in “Bulldog 805” Alfalfa + “Tifton 85” bermudagrass mixed stands

“…Overall, the reported TDN values from both locations were comparable to Beck et al (2017b), Hendricks et al (2020) for ABG mixtures harvested for grazing or stored forage on a 28-35 days HF. Conversely, the TDN values of the current evaluation for both the HH and HF treatments are greater than those reported by Burt et al (2022) and Rushing et al (2022) for ABG mixtures (both approximately 55% TDN).…”

“…It is not surprising that the observed CP from the Alabama samples was numerically greater than those reported in Georgia considering the difference in the alfalfa content discussed in the previous section. Despite the differences in the alfalfa component in the stand for both locations, the observed CP for both locations was greater than those reported by Marks (2020), Burt et al (2022), andHarling et al (2023) for ABG mixtures. In contrast, Beck et al (2017b) and Hendricks et al (2020) observed higher CP values than those in the current study at both locations.…”

“…Other forage nutritive values such as ADF were greater than the ADF reported by , Hendricks et al (2020), andBurt et al (2022) for both HH and HF treatments. It should also be noted that Harling et al (2023) reported ADF values higher than those observed in the current study at both locations for HH and HF.…”

“…The increase in the cost of synthetic N fertilizer has producers seeking alternatives for their forage systems (Quinn, 2022; United States Department of Agriculture: Economic Research Service [USDA-ERS], 2019). The interest in legume+grass mixtures has increased in recent years to alleviate the need for synthetic N applications (Biermacher et al, 2012;Burt et al, 2022;Rouquette & Smith, 2010;USDA-ERS, 2019;Vasco et al, 2023).…”

“…Growing forage legumes in mixtures with grasses is not a novel concept and is considered a viable and often desirable alternative to synthetic N fertilizer application (Burt et al, 2022). Outside of interseeding clovers ( Trifolium spp.…”