VENUS — When Archbold Biological Station teams up with the U.S. Department of Agriculture to study agroecology in the coming year, scientists will focus on cattle lands, but not how to stock more cows.
Research will focus on improving grazing grasses, habitat and plant diversity, but also on reducing greenhouse gases by trapping them in the soil and keeping them there, said Betsy Boughton, agroecology project director for the Venus-based research facility.
Archbold received a $499,921 USDA grant as part of a project to improve food production by studying and improving agroecosystems — the interaction of soil, water, sun, plants, animals and people. Agroecology research requires collaboration across several different fields. Archbold will work with the USDA, the University of Illinois at Urbana-Champaign and Cornell University. Cornell scientists will measure nitrous oxide produced from soils. Boughton said the USDA will measure methane, and University of Illinois scientists will study carbon dioxide.
Cattle ranching is a large land use in Florida, Boughton said. Of 3 million acres of Everglades watershed, from Orlando to Okeechobee, 1 million acres are ranch land.
Ranches are pasture, she said, but also scrub, wetlands, prairie and other native habitat for the caracara, burrowing owl and sandhill crane, as well as migration and open forage land for Florida black bear and panther. Ranches also provide water retention, she said. Keeping ranches helps keep the habitat and retention areas.
“This is an incredible opportunity for conservation,” Boughton said.
As it so happens, one of Archbold’s “research labs” is the MacArthur Agricultural Research Center, a 10,500-acre full-scale cattle ranch leased in 1988. Through it, Boughton said, scientists have learned “real world” facts on how ranches influence the environment and stay economically and environmentally viable.
“We have to stay in the black, (but) we don’t stay in the black every year,” Boughton said.
Archbold’s work at the ranch functions best at an average of three acres per cow, Boughton said: “That’s a good stocking density for us.”
Sometimes, Boughton said, Archbold has lifted and sold sod as a sideline, but for the most part, the ranch runs on cattle.
Agroecosystem research comes in because ranching — a large land use in Florida — needs to balance livestock production with the environmental goals of biodiversity, wetland restoration, greenhouse gas reduction and carbon sequestration — locking carbon in the soil, Boughton said. One area of study will look at grazing and fire.
“This project will look at how prescribed fire can manipulate the way cattle use pasture,” Boughton said.
Ranchers already use fire to clear pastures of shrubs and improve forage. Boughton said cows gravitate toward more recently burned areas, which reduces methane emissions from wet soil. When cows reduce the height of existing grasses, soil moisture increases, Boughton said. Wetter soil releases more methane.
Of methane measured on the ranch, just 30-40 percent comes from cows, she said. With “patch-burning,” ranchers could get cows to leave tall grasses alone.
Burning should also help re-establish Florida prairie, Boughton said. Shrub encroachment reduces it and it’s in decline. At present, Florida only has 1 percent of its original prairie lands left.
In the early days of Florida cattle ranching, floods and fires kept shrubs out, Boughton said. Ranchers were among the few using fire to clear land. Development changed that somewhat. Reduction in floods and fires changed let in shrubs.
“Archbold isn’t suggesting to go back to a flooded landscape,” Boughton said. “We want to manage habitat for ranch lands and scrub lands so species don’t go extinct.”
Using fire to improve grasslands and change the way cattle graze could also reduce the need for feed and fertilizer, Boughton said. Both are costly, and fertilizer spikes nutrient levels downstream in the Everglades. Manure, especially from ranching, has far less of an impact.