Designed and naturalized sward response to management: 1. Patterns of herbage production

Authors: BELESKY, DAVID - West Virginia University; Halvorson, Jonathan; RUCKLE, JOYCE - Retired ARS Employee; MATA-PADRINO, DOMINGO - West Virginia University

Submitted to: Annals of Applied Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/23/2019
Publication Date: 5/29/2019
Citation: Belesky, D.P., Halvorson, J.J., Ruckle, J.M., Mata-Padrino, D.J. 2019. Designed and naturalized sward response to management: 1. Patterns of herbage production. Annals of Applied Biology. 175:42-53. https://doi.org/10.1111/aab.12512.
DOI: https://doi.org/10.1111/aab.12512

Interpretive Summary: Pastures in the Appalachian region of the United States, like those growing in West Virginia, include a mix of grasses, legumes and forbs. While a pasture might be established to achieve a desired botanical composition, the original mixture of plants can change due to environment, management, time and natural variability. Change in pasture composition allows it to adapt to changing conditions but at the same time adds a measure of risk to a forage-livestock production system. Stable productivity, within and among growing seasons, can help reduce the uncertainty associated with producing livestock on pasture. We designed forage mixtures for specific functions, e.g., dry matter productivity, seasonal distribution of production and nutritive value, and compared these to a naturalized pasture plant community. Productivity differed among years reflecting patterns of sward establishment and environmental variations. Clipping influenced the proportion but not always the occurrence of species or dry matter productivity. The number of species in fertilized, frequently clipped plots decreased with time suggesting that increased diversity was not always related to greater productivity. Maximum productivity was influenced by sward composition and less so by management. The relative yield of designed communities did not always exceed that of unfertilized, naturalized pasture clipped at 6-wk intervals, but were greater when fertilized, regardless of clipping frequency. The naturalized pasture plant community tended to have the greatest sustained herbage productivity, except in a relatively dry growing season when the warm-season community produced the most herbage. Forage plant communities integrate the effects of the biological and physical environment. While specialized forage mixtures can be favored by some conditions, diverse naturalized swards offer a means to sustain productivity because they can respond to uncertain environmental stressors over time.

Technical Abstract: Pasture in the Appalachian region of the United States, typified by those growing in West Virginia, includes a mix of native and naturalized grasses, legumes and forbs. While pasture might be established to achieve a desired botanical composition, the original mixture of plants respond to environment, management, time and the stochastic nature of complex biotic systems and often differ from the originally sown proportions. The result is a dynamic floristic composition that adapts to changing conditions but at the same time adds a measure of risk to a forage-livestock production system. Stable productivity, which might be considered as resilience or resistance to change induced by biotic and abiotic stresses, within and among growing seasons can help reduce the uncertainty associated with producing livestock on pasture. We designed forage mixtures for specific functions, e.g., dry matter productivity, seasonal distribution of production and nutritive value, and compared these to a naturalized pasture plant community. Productivity differed among years reflecting ontogenetic and environmental variations. Clipping influenced the proportion but not always the occurrence of species or dry matter productivity of the sward. The number of species in fertilized, frequently clipped swards decreased with time suggesting that increased sward diversity was not always related to greater productivity. Maximum productivity was influenced by sward composition and less so by management. The relative yield of designed communities did not always exceed that of unfertilized, naturalized pasture clipped at 6-wk intervals, but were greater when fertilized, regardless of clipping frequency. Naturalized swards tended to have the greatest sustained herbage productivity, except in a relatively dry growing season when the warm-season community produced the most herbage. Forage plant communities integrate the effects of the biological and physical environment. While designed forage swards can be favored by some conditions, diverse naturalized swards offer a means to sustain productivity because they can respond to uncertain environmental stressors over time.