From patch-burn grazing, grubbing cedar and roller-chopping cactus to spraying young mesquite, “brush sculpting” is an art that can carve out good grazing on marginal land.
Brush sculpting is also the planned, selective control of brush to enhance wildlife habitat consistent with other land uses.
Whether you're interested strictly in pounds of gain per acre or blending cattle with wildlife conservation, rugged areas of the Southwest and other regions present opportunities to do both. And with the added value many ranchers are seeing in leasing land for hunting rather than beef production, one can be just as important as the other as profit centers.
For livestock production, Texas A&M University range and wildlife management specialists say brush sculpting might include reducing mesquite, prickly pear cactus or juniper coverage on the best soils, or clearing a calving pasture to make it easier to view the animals. For quail and other birds, it could mean leaving some existing cover to create “usable space.”
Specialists say whitetail deer management may benefit most from selective brush sculpting that increases the diversity of forbs and quality browse while reducing unused brush and maintaining sufficient screening and escape cover.
Dale Rollins, Texas AgriLife wildlife specialist and director of the Rolling Plains Quail Research Ranch at Roby, says a combination of mechanical brush removal and periodic herbicide treatments for mesquite and other nuisance plants is likely needed in a successful brush-sculpting program.
“As a colleague says, ‘Brush sculpting is a process, not a project.’ One should always have a maintenance plan to extend the treatment life,” he says.
A cost of up to $200/acre may be needed if rangeland is heavily populated in mesquite, cedar, juniper and cactus. But the treatment life can be extended for decades with a solid individual plant treatment (IPT) program or well-timed prescribed burns, depending on the brush community involved.
Rod Hench winters about 400 stocker cattle east of Snyder, TX. He also uses about every sculpting tool available. While cattle are important to the West Texas operation, it's more contoured for quail, deer and other wildlife. Where many producers would control-burn 1,000 acres to generate spring and summer grass, he creates 100-acre sections.
“We'll divide the 100 acres into quarters numbered 1, 2, 3 and 4,” he says. “In the first year, we'll burn and/or chop the 1s, while plowing and seeding strips with wheat, vetch and yellow sweat clover in sections 2, 3 and 4. In section 1, we'll roller-chop as much as possible as to not top-kill our ‘quail houses,’ then burn the areas too thick to chop. The second year, we rotate to another quadrant, etc., until all quadrants are chopped and/or burned in a four-year rotation.”
In his stocker program, cattle are usually placed on grass in previously burned fields. That's in November and they're grazed until April, when they're sold at regional auction sales. He could run many more cattle longer periods of time, but he would rather spend his retirement raising and protecting wildlife and hunting with family and friends.
A former outfitter for hunting leases, high school football coach and businessman, he and his wife bought the ranch seven years ago. Seeing the vast amount of work needed for his dream of a wildlife haven, he acquired an excavator, a D5G dozer, a skid steer and a roller chopper.
He and two employees sculpt the land. Besides removing unwanted trees, bushes and cactus, they also mold watersheds to catch rainfall in rare downpours. He's also added solar-powered pumps for water wells. “Water that would normally run off is now stored on the ranch for up to three years through our watershed and well program,” he says.
Hench sculpts land to where quail can reach shrub cover every 25 yards away to escape predators like a hawk. These “quail houses” (less dense patches of mesquite or cactus) also allow for loafing and thermal protection during hot or inclement weather.
The 25-yard rule is similar to Rollins' “softball” approach to managing quail at the Rolling Plains ranch. “There should be quail houses separated by about as far as you can throw a softball,” says Lloyd LaCoste, research technician at the Rolling Plains Quail Research Ranch.
Like Rollins, Hench also uses a patch-burn program geared more toward quail habitat. But Rollins' patch-burn trial is to assess the impact of such focused grazing on quail habitat, and hopefully a quail-friendly approach to prickly pear control.
The experimental ranch has two pastures used in the patch-burn-grazing trials. Each is stocked with a small herd of cows — one with 28 cows, another with 18 cows and a bull. Two cows in each pasture wear GPS collars to track their grazing whereabouts by satellite.
“The system takes a point of the cow locations every half hour,” says LaCoste. “We know where they're grazing virtually all of the time.”
While a typical rotational grazing program would seek to limit grazing for short periods of time by fencing and other means, the patch-burn program seeks to keep cattle grazing a particular area for longer periods of time. This leaves the unburned portions of the pasture lightly grazed while the burns get grazed intensively, thus shifting the vegetation from grasses to weeds, which quail prefer for food. The result is a mosaic of nesting habitat and feeding areas, Rollins says.
“Through the GPS readings, we see that the cows and their calves spend most of their time on the patch-burned area,” LaCoste says.
In the patch-burn program, 10% of a pasture is burned annually, usually in February or March. Scientists will monitor how the intensive grazing affects cactus survival, vegetation dynamics, insect populations and quail use.
Mesquite regrowth is the primary brush problem on the quail research ranch and for most ranchers in the Rolling Plains of Texas. To stymie that growth, an IPT program is used. In this foliar herbicide program, mesquite that's about a head tall or shorter is sprayed from ATVs with a mix of Remedy and Reclaim herbicides from Dow AgroSciences.
Applicators work to assure that all leaves are covered with the herbicide mix. The foliar method handles the vast multiple-stem growth seen in mesquite. An annual spraying program keeps most of the mesquite in check.
“We try to target two pastures (about 800-1,000 acres) each summer for IPT,” Rollins says. “We sprayed about 5,300 mesquite trees in 2008 using the ‘Brush Buster’ IPT foliar method of Reclaim and Remedy mixed with water and a surfactant. If we deem some areas too open for quail, we simply leave the mesquite unsprayed over areas the size of a basketball court. We refer to these unsprayed trees as ‘strategic mesquites.’”
Other Texas AgriLife research adds to theories that brush density affects grazing distribution. In the tests in South Texas, sensor-tagged cattle had access to areas with or without mechanical brush suppression treatments.
GPS satellite fixes were four times higher in treated vs. non-treated areas, where forage quality was also reported to be higher. AgriLife studies also show that cattle in a more hilly area spent 98% of their time on areas with slopes of l1% or less. These trials show it's important to recognize and account for true pasture usage.
Steven Whisenant, head of the A&M Ecosystems Services and Management in College Station, says these and other research programs illustrate that grazing distribution problems can be improved with brush control. Water distribution and access, fencing layout, road and trail development in steep topography and other measures can also impact grazing.
“Other situations may not easily lend themselves to management or improvement,” he says. “But still, they need to be accounted for when determining stocking rates in those pastures.”
He adds that, in general, “brush-sculpting methods that treat individual plants are more practical in areas with lower plant densities. Broadcast-applied methods, such as aerial spraying, are often restricted by reduced selectivity.
“Since greater brush changes require more effort [time, money and labor], brush sculpting activities that occur during the preventive maintenance or early intervention stages are most effective.”
Larry Stalcup is a freelance writer based in Amarillo, TX.