Using a warm season grass (bottom photo) or a grass-legume mixture (top photo) helps give year-round, high quality pasture for livestock in a pasture rotation.
Keep your goals in mind as you consider forage options for a pasture system. Also consider how you plan to rotate and rest the pastures. Most productive grazing systems allow for resting of pastures for regrowth and include a mix of species that leave no gaps in production.
The production chart on the right shows that no single grass produces high all year round. The gap created in the hot summer months with cool season grasses can be filled with warm-season grasses or with a mixture of cool season grasses and legumes.
For ease of management and best use when starting a grazing program, mixtures should have no more than two grasses with similar growth habits. You can increase diversity of stands as you become more experienced in grazing management.
Common grass-legume mixtures in Iowa are alfalfa with bromegrass, orchardgrass or tall fescue; ladino clover with orchardgrass, timothy or smooth bromegrass; red clover with orchardgrass; and birdsfoot trefoil with Kentucky bluegrass, smooth bromegrass or timothy.
Choosing forages for a year-long system
These recommended guidelines are for beef cattle and may vary for different livestock.
Winter January 1-March 20
The forage is likely to be hay crop residues or stockpiled forages. It should be good quality because the nutrient level requirements are high for beef cows during this period, just prior to spring calving.
Stored pasture March 20-April 20
A cool season pasture with forage from the previous year works well here. Kentucky bluegrass, bromegrass or tall fescue produce a heavy sod that would work well in the spring thaw. It may be necessary to supplement stored forage with good quality hay.
Spring pasture April 20-June 15
Cool season grasses begin their growth as temperatures rise in the spring. Reed canarygrass and Kentucky bluegrass are the two earliest producing grasses. Smooth bromegrass, orchardgrass and tall fescue can also be used. Consider mixing legumes with these grasses to improve forage quality and supply nitrogen for the grasses.
Summer pasture June 15-September 15
This period has traditionally produced the poorest pasture. One option is to use mixtures of cool-season grasses and legumes, such as smooth bromegrass/alfalfa; orchardgrass/birdsfoot trefoil; and tall fescue/red clover. Another option is to use warm season grasses. Switchgrass, which matures earliest of the three primary native grasses, can be used in June. Big bluestem and Indiangrass mature two to three weeks later.
Fall pasture September 15-November 10
Use cool season grasses again and stockpile some for early spring use. Rest grass-legume mixtures through the first half of this period to maintain a healthy legume stand.
Early winter November 10-January 1
Cornstalks and second growth cool season forage all work well here. Excess warm season grass forage may be another option, which is usually lower in quality but still suitable.
Use these guidelines to establish pastures:
Lime and fertilize according to soil tests.
For conventional seeding, work a seedbed on the contour to a depth of 3 inches.
If erosion or weeds are a problem, seed a companion crop of oats at a bushel-plus an acre.
Drill seed at a depth of 1/4 to 1/2 inch deep.
Consider no-till seeding on steep slopes.
To interseed grasses or legumes into low producing pastures, graze or clip closely. You may need to apply a burndown herbicide to suppress existing growth.
Interseed at only half the rate of full seeding.
Optimum seeding times for cool-season grasses are March 1-May 15 and Aug. 1-Sept. 15. For warm season grasses, seed from April 1-June 1. Dormant seeding dates for both are from Nov. 1 to freeze-up.
Frost seeding of some legumes, especially red clover and birdsfoot trefoil in late February or early March can help improve a pasture.
Inoculate legume seeds by the wet method, with inoculants specific to the legume seeded.