Research project benefits both ducks, rice farmers

Contact: Bob Ratliff

While some practices that protect the environment and benefit wildlife don't yield economic benefits, a Mississippi State research team is finding that what's good for ducks also can boost rice farmers' profits.

Beginning in the winter of 1995-1996, scientists at the university's Forest and Wildlife Research Center studied 72 Mississippi rice fields covering more than 3,000 acres in four Delta rice-producing counties: Bolivar, Leflore, Sunflower, and Washington. In particular, they looked at the impact of rebuilding levees and flooding rice fields following the fall harvest.

Called winter flooding, the practice currently is used only on about 10 percent of the more than two million acres of rice land in the Delta region of Arkansas, Missouri, Mississippi, and Louisiana.

MSU wildlife and fisheries professor Rick Kaminski said the practice offers benefits for farmers, wildlife and the environment.

"We knew the winter flooding of rice fields has tremendous potential for providing wetland habitat for ducks and other waterfowl," he said. "What we needed to determine was whether the practice might positively impact the environment and the management of the land for rice production."

The four-year research project was conducted by then-doctoral candidate and Ducks Unlimited regional biologist Scott Manley under the direction of Kaminski and associate professor of forestry Stephen Schoenholtz. Manley, of Stuttgart, Ark., graduated in December.

Kaminski said rice producers at several Delta locations allowed the scientists to use their fields for the research. Included in the project was a comparison of soil loss from winter flooded fields and those where water was allowed to drain freely following winter rains.

MSU scientists found that in fields where soil was disked after harvest and rainfall was allowed to drain freely, an average of 1,000 pounds of soil per acre was lost during the winter. In fields where rice stubble was left undisturbed after harvest and water was impounded, an average of only 31 pounds of soil was eroded.

"The research shows that the reduced erosion helps hold nutrients in the fields and improves the quality of run-off water," Manley said.

An additional benefit of winter flooding is reduced problems with winter growth of weeds and help with decomposing rice straw.

"During the winter, farmers must contend with problems such as growth of weeds and disposal of rice straw left after harvest," Manley observed. "Our research indicates that winter flooding significantly reduces rice straw and growth of cool-season grasses and weeds, which can reduce the need for herbicide treatment of weeds before spring planting."

MSU scientists estimate the combination of increased decomposition of rice straw by winter flooding, plus the inhibited growth of weeds, can save farmers up to $22 an acre in spring field preparation costs.

And what about benefits for the ducks?

"The birds consume rice and aquatic invertebrates in flooded rice fields," Kaminski said. "Flooded fields were found to support high populations of invertebrates, like snails and earthworms, which are important foods for waterfowl and other birds.

"With the decrease of natural wetlands throughout the South, rice fields also can provide critical habitat for migrating waterfowl and shorebirds."

Manley said the research confirms the value of programs by government organizations and private conservation groups promoting the use of rice fields for winter waterfowl habitat.

"The study shows that winter flooding is an opportunity to integrate wildlife management into an existing land-use system with significant benefits for landowners and waterfowl," he added.