"Drainage Management Pays Off"
by Bob Oertel
Don Pitts and Richard Cooke host members of the Ag Drainage Management Task Force on a tour of a University of IL Controlled Drainage research site.
When Paul Pullins and his Dad, David, were installing subsurface drainage systems in western central Ohio, they kept wondering if sometimes the tile might be draining off too much water. Especially in the summer when crops were growing. "Maybe, just maybe", Paul remembers thinking, "it is just common sense to keep some of that water in the ground for the crops to use."
They probably didn't realize then how deep they were getting into the whole subsurface drainage management field. They probably also didn't realize how this might change the way they installed systems and how they might improve systems already in the ground.
While searching through a catalog from Agri Drain, a supplier of water management products, Paul and David noticed that inline water level control structures were available. "These might be a good thing," they reasoned, so ordered one and installed it in an existing system. That was a start. Since then, they've installed about 40 such structures in west central Ohio.
Hundreds, perhaps thousands, of similar structures have been installed by drainage contractors, particularly throughout the North Central Region of the USA. Study of the practice is yielding valuable research on water management aimed at agricultural production as well as addressing environmental problems resulting from drainage water.
First One On Boerger Farm.
Stoplogs, made of 1/2" thick PVC sheet, were placed in the structure to adjust to whatever level of drainage is desired. In operation, water from the tile line enters the box, flows over the stoplogs and out the downstream side of the structure. Barry sets his stoplogs for a 12" drainage level for corn and 18" level for soybeans. There is a feeling among some farmers that the 18" level can be set for all crops.
Generally, stoplogs are not placed in the box until crops are 6" to 8" tall. Once in, some feel that the level of control should not be changed. Paul has observed that some farmers, however, are tempted to adjust the levels when heavy rains occur. An automated control box being developed by AgriDrain is expected to be available in late 2003.
"We cannot expect the end user to go to each water level control structure and manually adjust stoplogs 4 or 5 times per year," says Charlie Schafer, President and owner, AgriDrain. "Our new Water Level Control Structure is a solar-powered unit that is computer controlled to raise and lower the water table at various times of the year to meet the needs of the producer and the crop."
Charlie adds, "We are excited about the economic benefits that drainage water management can provide for our contractor customers and the land owners they serve and for the environmental benefits through improved water quality in our lakes, rivers and oceans. We are pleased to play a role in the promotion and implementation of this worthwhile practice."
Barry says he sees slight increases in yields from the 75 acres where he has boxes installed. He has 5 boxes, each controlling about 15 acres of drainage. Barry says the biggest benefits will likely come in dry years.
Louis McFarland, President, LICA, who has been installing water level control boxes for some 7 years, says that their use does bring better crop yields, but exactly how much is uncertain. "Yield monitoring is either generally missing or inadequate," he says. "We need better data. There is still much we need to know about controlling drainage."
USDA Research, Education and Extension Service, in Science & Education Impact' reports on controlled drainage benefits in North Carolina. A controlled drainage system developed by scientists at North Carolina State "increases crop yields and cuts water pollution. Thanks to NC Extension programs, controlled drainage is now used on 600,000 acres. One result: increased corn and soybean yields have added $5 million annually to the state's gross agricultural income."
Drainage Water Quality: A Major Concern
"Most research in the past has concentrated on removing groundwater rather than also on the quality of that water," says Dr. Gary Sands, University of Minnesota, St.Paul Campus. Sands is Assistant Professor and Extension Engineer-Water Resources.
He says, "The loss of nitrates carried away by drainage water is a national concern, particularly in the Upper Midwestern states of Minnesota, Iowa and Illinois. In those states, there are large cultivated areas tiled because of poorly drained soils. The Upper Mississippi River Basin alone contributes 22% of the flow and 31% of the nitrates in the entire Mississippi River system. We hope our research findings may help us design future systems that will cut down that nitrate loss, thus improving the quality of drainage water."
Ron Turco, Director, Purdue Environmental Sciences and Engineering Institute, says, "A first step to reduce the amount of nitrate runoff would be to improve tile drainage-water management on farms. I maintain that a good chunk of water that is discharged into the Mississippi River and the Gulf of Mexico starts as tile water from agricultural drainage systems. I'm more convinced of this every day."
The University of Minnesota established the Agricultural Ecology Research Farm (AERF) in 1999 on a previously undrained dairy farm near Waseca, MN. In addition to the research aimed at improving water quality and increasing crop responses, there are studies on the performance of alternative surface drainage inlets and on the economic feasibility of controlling drainage on farms similar to the systems already in use in the Carolinas.
The Minnesota Land Improvement Contractors Association (LICA) is one of the Project Partners in this ambitious research effort. Many of them donated their equipment and time to help install the various drainage increments during a 3-day Field Day in August, 1999.
Most drainage flow occurs during the fall, winter and early spring when there are no crops on the land. Significant N losses occur during this time as compared to the crop growing seasons. It follows then that reducing the amount of drainage flow will in turn cut down N losses. The University of Minnesota Extension Service reports that "Numerous studies indicate that controlled drainage has a potential to reduce Nitrate-N losses by up to 60%".
Don Pitts, an agricultural engineer and water quality specialist, with the Natural Resource Conservation Service (NRCS) in Illinois, is concerned about drainage management. NRCS is working with more than 30 Illinois farmers to install water level control structures, most of which are placed in existing tile systems.
Pitts says, "We're using drainage management so as to minimize the water flow through the tile when we don't have crops in the ground. The loss of nitrates in farm fields is greater when there are no crops in the field, so why have drainage when we don't need it."
A Strong Drainage Management Supporter
His main equipment includes 2 Interdrain 2050 drainage plows and backhoes. Two years ago, he began using GPS (Global Positioning System) on both plows. He estimates he has increased his production by at least a third since using GPS.
Paul is convinced that the use of water level control structures is a good thing, not only for farmers but also for the environment. "I've seen first hand what they can do and I urge every drainage contractor to get acquainted with them if they don't already know how they can help farmers."
For more information, contact: Paul Pullins, Pullins Drainage 12662 Shanley Rd., Quincy, OH 43343. Ph: 937-362-2665 . Email: email@example.com or; Charles Schafer, Agri Drain, P.O. Box 458, Adair, IA 50002 Fax: 800-282-3353, Email: firstname.lastname@example.org Ph: 1-800-232-4742
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