Evaluating warm-season annual forages to fill summer forage gaps in short-season climates

Authors: Billman, Eric; ALEXANDRE DE SOUZA, IGOR - Universidade Federal Dos Vales Do Jequitinhonha E Mucuri; SMITH, RICHARD - University Of New Hampshire; Soder, Kathy; WARREN, NICHOLAS - University Of New Hampshire; BRITO, ANDRE - University Of New Hampshire

Submitted to: Crop, Forage & Turfgrass Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2021
Publication Date: 1/20/2022
Citation: Billman, E.D., Alexandre De Souza, I., Smith, R.G., Soder, K.J., Warren, N.D., Brito, A.F. 2022. Evaluating warm-season annual forages to fill summer forage gaps in short-season climates. Crop, Forage & Turfgrass Management. 8(1):e20152. https://doi.org/10.1002/cft2.20152.
DOI: https://doi.org/10.1002/cft2.20152

Interpretive Summary: Summer may be the most challenging season for dairy and beef producers to provide adequate quantities of high-quality forage to grazing livestock. Oats have typically filled this niche, but warm-season annual forages may offer a better alternative option for producers in climates such as New England where the period of warm weather is typically short (June - August) and limits forage production. Research conducted in New Hampshire over a 2-year period compared the productivity and forage quality of four warm-season annual forages (Brown midrib sudangrass, buckwheat, Japanese millet, and teff) to two cool-season annual forages (oats and chickling vetch). Results of this work indicated species that produced more forage mass, such as buckwheat, exhibited very poor forage quality, while forages with greater forage quality, such as chickling vetch and teff, produced less forage mass. Species with better median performance, such as Japanese millet, were more suitable for summer forage production in New England than oats due to maintaining a more balanced ratio of forage mass to nutritional value.

Technical Abstract: Annual warm-season forages have been used to fill productivity and nutritional gaps during summer months throughout the southeastern United States. However, their performance and nutritive value in cooler, short-season temperate climates above 40°N has been less well studied. This study evaluated the forage mass and nutritive values of four warm-season annual forages (brown midrib (BMR) sudangrass [Sorghum bicolor ssp. Drummondii (L.) Moench;], buckwheat (Fagopyrum esculentum Moench), Japanese millet [Echniochloa esculenta (A. Braun) H. Scholz], and teff [Eragrostis tef (Zuccagni) Trotter]) compared to a standard cool-season summer small grain forage, oat (Avena sativa L.), and a cool-season annual forage legume, chickling vetch (Lathryus sativus L.). Monocultures of the six annual forage species, along with a mixture of all six species, were evaluated over two years in southeastern NH. Forage mass and nutritive values were assessed at weekly intervals over three weeks in July-August, approximately four-to-five weeks post-germination. Across all three harvests, buckwheat, Japanese millet, and the summer mix produced greater forage mass than oat, while chickling vetch and teff produced the least. Conversely, CP of chickling vetch was greater, and ADF and NDF were lower compared to oat, while buckwheat had the lowest CP, IVTDMd, and IVNDFd of all the species assessed. Japanese millet produced greater forage mass while providing similar nutritive value as oats, making it a good alternative warm-season annual forage for use in cool, short-season growing regions.