Managing interspecies competition to improve spring pasture

Authors: Mercier, Kelly; Billman, Eric; Soder, Kathy; Jaramillo, David; Goslee, Sarah; Adler, Paul

Submitted to: Grassland International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/23/2023
Publication Date: 12/29/2023
Citation: Mercier, K.M., Billman, E.D., Soder, K.J., Jaramillo, D.M., Goslee, S.C., Adler, P.R. 2023. Managing interspecies competition to improve spring pasture. Grassland International Congress Proceedings. p. 1.

Interpretive Summary: Pastures and hayfields can get over-mature, which reduces their nutritional quality, if not harvested early enough in the spring due to wet field conditions. This study investigated whether the shade from chicory, a tall-growing forage, could delay the rate of orchardgrass maturity and affect pasture nutrition during the spring, as has previously been documented in on understory forages in agroforestry systems. In the first year of the study, chicory did delay orchardgrass maturity and increased pasture production. However, chicory died out over the winter. Although there was very little chicory in the second year, pastures that were initially planted with orchardgrass-chicory-white clover mixtures still showed greater yield and nutritional quality as compared to planting orchardgrass by itself. Further research is needed to increase chicory longevity in pastures to obtain a clearer picture of long-term effects on orchardgrass maturity and pasture production and quality.

Technical Abstract: Orchardgrass (Dactylis glomerata L.) is one of the earliest maturing pasture grasses utilized in the northeastern United States. However, wet springs can delay forage harvesting resulting in advanced forage maturity and reduction in nutritive value. Chicory (Cichorium intybus L.) is a tall, upright-growing forb that shows promise as a high-energy companion crop to orchardgrass and may delay orchardgrass maturity through shading effects on plant morphology. The objective of this study was to evaluate monocultures and mixtures of orchardgrass, chicory, and white clover (Trifolium repens L.) over two consecutive springs to determine the effects of species diversity on plant maturity, nutritive characteristics, and botanical composition of forage mass. Forage monocultures and mixtures were planted in central Pennsylvania in August 2018 and were observed for two years with three harvests occurring each year (one each in spring, summer, and fall). In the first spring, orchardgrass demonstrated nine days delay in maturity when grown with chicory as compared to when grown in monocultures or in OG:WC mixtures. Although orchardgrass was at an earlier developmental stage, fiber concentrations were similar when grown with or without chicory. Additionally, in the first spring, orchardgrass mixtures containing chicory had 1.5x greater forage mass than OG monocultures and OG:WC mixtures. Chicory biomass was low in the second spring, likely due to winterkill following a late fall harvest the previous year, resulting in a negligible effect on orchardgrass. However, orchardgrass-chicory-white clover mixtures (even with low amounts of chicory in the second year) had the greatest forage mass and nutritive value yield over both years, indicating that these mixtures can provide greater agronomic benefits than orchardgrass monocultures.