Forage Systems for the Upper Transition Zone that Utilize Bermudagrass and Cool-Season Annual Grasses.

Bermudagrass [Cynodon dactylon (L.) Pers.] cultivars are commercially available that have the cold hardiness to persist in the colder climate of the upper transition zone. The grass has a short growing season of 4 to 5 months in the region, which requires that pastures be over-seeded with cool-season annual grasses to increase total forage production and extend the grazing season.  A 3-yr, small-plot experiment was conducted to compare cumulative dry matter yields for ‘Wrangler’ bermudagrass that was drilled with either rye (Secale cereale L.), ryegrass (Lolium multiflorum L.), wheat (Triticum aestivum L.), rye-ryegrass, or rye-wheat.  Plots were harvested with cutting heights of either 5 or 10 cm.  Bermudagrass production also was compared between a bermudagrass-only control and the cool-season grass treatments.  Harvests were from late April or early May to late-August or late September with an approximately 21-d harvest interval that simulated rotational stocking.  Highest (P < 0.05) cumulative dry matter yield was obtained by the rye (3-yr mean = 6815 kg DM ha^-1), ryegrass-rye (3-yr mean = 6840 kg DM ha^-1), and rye-wheat (3-yr mean = 6161 kg DM ha^-1) treatments.  Although ryegrass was lower in total forage production than rye and the two mixtures, it (3-yr mean = 5639 kg DM ha^-1) consistently had greater (P < 0.05) total production than wheat (3-yr mean = 3001 kg DM ha^-1).   Cutting height effects were generally detected for summer harvests when bermudagrass yields were higher (P < 0.05) with the 5-cm height.  Cumulative bermudagrass growth was consistently highest (P < 0.05) for the control plots, but there was no visible deterioration of bermudagrass from competition with the cool-season annuals.  For the upper transition zone, overseeding bermudagrass with cool–season annual grasses can increase total forage production and length of the grassing season, but at the expense of bermudagrass production.