Seeding date effects on yield and nutritive value of cool-season annual forage mixtures

Increasing the grazing season and improving distribution of cool-season ann ual forages would benefit pasture-based dairy systems in North Florida. Six cool-season forage mixtures, rye (Secale cereale L.)- oat (Avena sativa L. ), rye-oat-crimson clover (Trifolium incarnatum L.), rye-oat-red clover (T. pratense L.), and each of these plus ryegrass (Lolium multiflorum Lam.) we re seeded at 4-wk intervals from September to December of 1996 and 1997 on loamy, silicious, thermic Grossarenic Paleaquult and hyperthermic Grossaren ic Paleudult soils near Gainesville, FL. Forage yield, seasonal distributio n of yield, and nutritive value were measured. The rye-oat-ryegrass mixture was highest yielding in both years, but it was not different from rye-oat- crimson in 1996. October and November seedings resulted in greatest dry mat ter (DM) yield for most mixtures, but the rye-oat mixture tended to have gr eatest yield when planted in September. The rye-oat mixture was productive through early April, but adding ryegrass or clovers to it extended the prat ing season. Forage nutritive value was high although it declined during lat e spring as plants completed their growth cycle. These data support the use of complex mixtures for best seasonal distribution of yield and nutritive value. Small grains contributed early production, ryegrass provided high sp ring yields and high nutritive value, and the clovers, especially red clove r, provided late-spring growth to extend the grazing season. Choice of appr opriate mixtures may allow production of forage for grating from late-Decem ber/early January to May (5 mo), a period in which perennial warm-season gr asses lack both the yield and nutritive value necessary for lactating dairy cows.