Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/25/2006
Publication Date: 5/11/2007
Citation: Deak, A., Hall, M., Sanderson, M.A. 2007. Forage production and nutritive value of complex forage mixtures under rotational grazing. Agronomy Journal. 99:814-821. Interpretive Summary: Complex mixtures composed of species with marked differences in seasonal growth pattern may provide higher yields than simpler mixtures. In this research we compared forage production, nutritive value, and botanical composition of forage species combined in simple mixtures (2 and 3 species) and in more complex mixtures (6 and 9 species) under rotational grazing management. Mixtures containing 6-species produced more forage compared to the simple mixtures. However, forage production varied within species richness groups. Thus forage production was influenced more by species composition than by mixture complexity. We conclude that species selection is more important than mixture complexity in achieving high yields and forage quality with forage mixtures. The assemblage of forage mixtures containing the best adapted species to a particular environment and management will provide the highest yield and quality.
Technical Abstract: Sustainability of forage production in the Northeast USA is negatively affected by environmental and climatic variability. Complex forage mixtures may be better adapted to variable environments and produce more dry matter (DM) more evenly throughout the growing season than simple mixtures. We evaluated forage production, nutritive value, and botanical composition dynamics of well adapted and commonly sown species combined in simple mixtures (2- and 3- species) and in more complex mixtures (6- and 9- species) under rotational grazing management. Dry matter distribution during the growing season was highly influenced by the weather and independent of mixture complexity. Mixtures containing 6-species produced more forage (9894 kg DM ha-1) compared to simple mixtures (8671, and 8444 kg DM ha-1 for the 2- and 3-species mixtures respectively). However, forage production varied within species richness groups. Orchardgrass, tall fescue, and white clover were the dominant species in several mixtures by the end of the study regardless of the initial number of species. Crude protein (CP) and neutral detergent fiber (NDF) were highly correlated with legume and grass proportion respectively. We conclude that species selection is more important than mixture complexity in achieving high yields and forage quality with forage mixtures.