Growing Sod With Manure
|A farm crew harvests Tifway bermudagrass sod grown with manure in an experimental field in Texas. Manure-grown sod can reduce phosphorus runoff. |
Photo by Don Vietor
Growing Sod with Manure Teams Two Texas Commodities
Fertilizers such as phosphorus, which may run off into streams and rivers, continue to raise environmental concerns. Texas researchers are promoting a crop that can, literally, take phosphorus away from livestock operations. SARE-funded Texas A&M University researchers grew high-end sod with manure on two large dairy operations and, when they harvested it, removed the phosphorus from the area.
Growing sod with dairy manure both reduced phosphorus loads and potential runoff from the dairies—up to 77 percent of applied phosphorus was removed in a sod harvest—and eliminated phosphorus fertilizer inputs used to grow conventional sod. Since manured fields, particularly when located near streams, create a phosphorus run-off hazard, “we hatched the idea that we could capture more nutrients with sod than any other crop,” said principal investigator Don Vietor of Texas A&M.
Vietor and his collaborators grew recent releases of warm-season and cool-season perennial grasses—high-end sod prized by developers—established in soil topped with raw manure or composted manure, which reduced odor concerns. They also seeded lower-end “sports” turf on sloping soils to study phosphorus runoff. The benefits were clear: They captured much of the phosphorus that would otherwise run off or leach from manure in a value-added product—a far more profitable alternative than hauling manure. When the sod was replanted or used in commercial settings, phosphorus run-off was reduced 9 percent compared to sod grown with commercial fertilizer. Moreover, manure improves water infiltration during turf establishment.
Using an economic model, collaborator Darrell Bosch at Virginia Tech estimated that a dairy farmer who used manure to grow 50 acres of sod could earn an additional $46,000 per year. That new profit was based on returns from sod minus the cost of buying corn silage, a new input for the farmer who took 50 acres of silage out of production to raise sod.
Vietor publicized the sod/dairy project at Texas grower meetings and will also reach out to extension educators. One dairy operator who collaborated on the project has already adopted the new crop, growing sod on part of the waste field for his large-scale replacement dairy heifer operation.
Vietor hopes that sod producers will consider forming partnerships with dairy farmers. “Sod producers now haul high-end sod to Dallas from as far as the Texas Gulf Coast,” he said. “Central Texas is a lot closer to Dallas. As sod producers look for new land, we’re encouraging them to look in these areas where dairies are concentrated.”
[For more information about this Southern Region project, go to www.sare.org/ projects and search for LS00-117.]