A four-year Texas Ag Experiment Station study found that adding a cool-season clover to a warm-season perennial grass was more profitable than applying high amounts of nitrogen for increasing calves' average daily gain. The clover extended the grazing season, had higher nutritive value and provided summer weed control, in addition to adding nitrogen to the pasture system, according to Gerald Evers, experiment station researcher.
Evers compared three systems:

• A high-input system on dallis grass pastures using 150 lbs/acre of nitrogen and herbicides for weed control.
  
  
• A medium-input dallis grass system where winter clover was overseeded into a stand of warm-season grass pasture.
  
  
• A no-input pasture system using no nitrogen, no herbicide and no clover.

Evers, now based at Texas A&M University's Overton research center, originally conducted the study at a site near Angleton in the 1980s. At that time, however, nitrogen fertilizer was relatively cheap. And other than summer weed control, the economic benefits to using a cool-season clover were not clear. With nitrogen costs topping 55 cents per pound in 2007, that situation has changed, Evers says.

Average daily gains for the calves were 1.57, 1.82 and 1.66 lbs/day for the high-, medium- and no-input systems. "Using 2007 costs for pasture and animal inputs, production costs per pound of calf gain were $1.12, 58 cents and 81 cents for the high-, medium- and no-input pasture systems, respectively," Evers states. Additionally, using clover in the medium-input system proved "as effective as applying herbicide in April for controlling summer weeds" in the high-input system, he says.

The original study was using dallis grass and white clover, both of which are well-adapted to the upper Texas Gulf Coast region. The system is just as applicable to more-northern regions of Texas, though different grasses and legumes would need to be used, he suggests. North of Interstate 10, soils are sandier and better drained. Bahia grass and bermuda grass are better adapted to these areas than dallis grass or white clover, he says. As for the clover component, arrowleaf, crimson and ball clovers are better adapted. Instead of only planting pure clover, Evers recommends mixing annual ryegrass with the clover to help alleviate concerns about bloat.

"By adding clover we started grazing five weeks earlier than if we didn't have clover, so that helped us by about $60/cow," Evers says. "So if you add ryegrass to the clover we could even start grazing another four to five weeks earlier than when we started grazing clover, and that would give you another $50-60 in winter feed cost savings per cow."

Evers cautions producers to take note of soil acidity before overseeding clover this fall. "You like to see the pH at 6 or higher," he says.

Contact Evers at 903-834-6191 or g-evers@tamu.edu