Enhancing the sustainability of temperate pasture systems through more diverse swards

Authors: Jaramillo, David; SHERIDAN, HELEN - UNIVERSITY COLLEGE DUBLIN; Soder, Kathy; DUBEUX, JOSE - UNIVERSITY OF FLORIDA

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2021
Publication Date: 9/24/2021
Citation: Jaramillo, D.M., Sheridan, H., Soder, K.J., Dubeux, J. 2021. Enhancing the sustainability of temperate pasture systems through more diverse swards. Agronomy. 11(10):1912. https://doi.org/10.3390/agronomy11101912.
DOI: https://doi.org/10.3390/agronomy11101912

Interpretive Summary: Temperate grazing systems can be highly productive, but are generally reliant on high inputs of nitrogen fertilizers. The use of legumes in these pasture systems has the potential to reduce reliance on nitrogen fertilizers. Recent research has evaluated the use of increased forage diversity in pasture systems, which contain species from different functional groups, including grasses, legumes, and forage forbs. To date, chicory and plantain have been the most common forage forbs utilized in these systems. Highly diverse pasture systems grown under reduced nitrogen-fertilizer inputs have the potential to produce as much biomass as high nitrogen-fertilized monocultures. The nutritive value of these swards may potentially be greater than grass-only pastures, especially since forage forbs contribute additional micro and macro minerals to the livestock diet. While challenges associated with managing diverse pasture systems may include weed management and sustaining persistence of forbs, the overall evidence suggests that well-managed diverse pastures can improve sustainable intensification by enhancing productivity while maintaining or improving environmental sustainability of grazing systems.

Technical Abstract: Temperate grasslands can be highly productive. However, those that are highly productive are generally heavily dependent on high inputs of nitrogen (N) fertilizer . Including legumes such as white clover (Trifolium repens L.) in the sward can reduce reliance on N fertilizer. Recent investigations have evaluated the potential of multispecies swards, which are defined as agronomically improved grasslands that include multiple plant functional groups, e.g., grasses, legumes, and forage forbs. To date, the most prominent forb species included in multispecies swards are chicory (Cichorum intybus L.) and ribgrass/ribwort plantain (Plantago lanceolata L.). Multispecies swards grown under reduced N-fertilizer input conditions can produce as much biomass as high N-fertilized monocultures. The nutritive value of multispecies swards may potentially be greater than grass-only swards , especially since forbs may contribute additional micro and macro-minerals to livestock diet. While challenges associated with multispecies swards may include weed management and facilitating persistence of the forb species in particular, the overall evidence suggests that well managed multispecies swards can enhance the productivity as well as envi-ronmental sustainability of grazing systems.