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Finding Answers to Drainage Questions

by Bob Oertel

Until a year ago, it was just another 160-acre tract of farmland, much like the other hundreds of thousands of acres of similar lands in southern Minnesota. Well, not exactly the same, for this land near Waseca had never been drained by field tile. And the dairyman-owner had used ‘alternative’ farming practices for many years.

One could drive by the farm without even noticing it. But all that changed in the summer of 1999. Now it’s no longer just another dairyfarm. Instead, it has a new, up-to-date, fancy sounding name and its mission has changed completely.

It is now the Agro-Ecological Research Farm (AERF), operated by the University of Minnesota Southern Research and Outreach Center located at Waseca. It’s being devoted to research to find answers to a number of lingering drainage and water management questions. The Center, one of 6 located around Minnesota to carry on site-specific research, represents one-sixth of the state’s area, but that produces one-third of the state’s cash farm sales.

An Unusual Research Site
The University purchased the farm in 1991. “We recognized that here was a rare and unique opportunity to look for answers to some of our continuing drainage questions,” says Dr. Gary Sands. He is Assistant Professor and Extension Engineer-Water Resources, Biosystems & Agricultural Engineering Department, U of MN - St. Paul Campus.

The farm was indeed different from its neighbors. Foremost, it had never been tile-drained and its scattered wetlands had been preserved. Its soil structure was less dense and there was less compaction caused by farm equipment.

“Most research in the past has concentrated on removing groundwater rather than also on the quality of that water,” explains Dr. Sands. “The loss of nitrates carried away by drainage water is a national concern, particularly in the upper Midwest 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 percent of the flow, and 31 percent of the nitrates in the entire Mississippi River system. We hope that our research findings here may help us design future systems that will cut down that nitrate loss, thus improving the quality of drainage water.”

In addition to the new research aimed at improving water quality and increasing crop responses, there are studies on the performance of alternative surface drainage inlets and on controlling the levels of drainage to possibly increase crop yields.

“Wetlands, like those on this farm, are an important feature in Minnesota landscapes and may offer valuable benefits with regard to hydrology and water quality,” Dr. Sands says. “We will use our findings here to help quantify these roles of wetlands and assess impacts of drainage on them.”

The Layout
The challenge of designing a system to accomplish the stated goals on the farm rested with Dr. Sands and Dr. Lowell Busman, Extension Educator-Water Management, U of MN. They eventually came up with a plan that includes nine separate zones, varying from 2 to 6 acres in size and drained by perforated tubing (formerly known as ‘tile’). Two of these zones outlet directly into a non-perforated main that carries water off the farm. The other 7 zones empty into non-perforated mains that drain into existing wetlands on the farm. Three grass waterways carry surface water on the farm into the wetlands. Excess water from the largest wetland is released into one of the tile mains and leaves the farm.

The 4” diameter perforated polyethylene tubing in the drainage zones is placed at varying depths and spacings. Tubing in two of the zones is at a 4’ depth, with an 80’ spacing. There is concrete tile in another zone at the 4’ depth and at the 80’ spacing. Two other zones have tubing at the 4’ depth, but with lines at only a 40’ spacing. Four other zones have tubing at a 3’ depth, two with a 60’ spacing and two with a 30’ spacing.

The quantity of underground flow from each zone is measured by ‘tippling’ buckets. The water will be tested to determine the amount of nitrogen being removed. Large manholes at the outlet ends of each zone provide access for researchers to the buckets and recording devices.

One of the zones (4’ depth and 40’ spacing) is a controlled plot. Movable baffles can be added or removed to achieve different depths of drainage. This feature makes it possible to determine effects on crop yields and amounts of nitrogen loss at different levels. Researchers are anxious to find out about the economic feasibilty of controlling drainage on farms in the upper Midwest, similar to the systems already in use in the Carolinas.

“Using these variations in depth and spacings, and by controlling drainage depths, we hope to get a much more complete picture of hydrology and water management,” explains Dr. Sands.

The Workshop and Field Days
Once the elaborate plans were complete, it was time for the next step in the MN Drainage Research and Outreach Project. The three-day 1999 Agricultural and Drainage Workshop and Field Day was held August 10-12 in the 4-Seasons Arena at Owatonna, MN and on the AERF near Waseca. Sponsors included: the U of MN Southern Research Center, Waseca; Iowa State University, Ames; MN Land Improvement Contractors (LICA); and IA LICA.

A wide range of attendees came from throughout the Midwest, from Ontario and as far away as Australia and New Zealand. They heard leading researchers, scientists, business and government representatives discuss such comprehensive subjects as Drainage System Design, Drainage and Wetlands, Drainage and Watershed Management, Future Challenges and Opportunities Facing the Drainage Industry and International Drainage Issues. Attendees then viewed the various research and demonstration projects on the AERF itself.

“This farm is where the action was,” is the way Barney Fleuger, then MN LICA President, puts it. “It was amazing that so many of our LICA members donated their time and equipment to put in all the systems. Of course, I wasn’t really surprised because these folks are anxious that the public knows and understands the kind and quality of land improvement work that LICA members do.”

Pattie Krengel, 2000 MN LICA President, calls the LICA members’ turnout and work a total success. “So many of them from all over the state came on their own, brought their equipment, and donated their work to make the field day the success that it was. They shared experiences with each other and in all ways enjoyed helping on this project that will mean so much to all of us in the future.”

LICA members (all but one from Minnesota) who brought equipment and worked at the field day included: Barnett Bros., Kilkenny; Don Loken Excavating, Owatonna; Drainage Design and Survey, Claremont; Ed’s Backhoe Service, Owatonna; Ellingson Drainage Inc., West Concord; Estrem Excavating, Dennison; Gregor Tiling, Minnesota Lake; Hector Tile Co., Hector; Hodgman Drainage Co., Claremont; Krengel Bros., Mapleton; J.R. Bruender Construction, Inc, Eagle Lake; L & E Farm Drainage, Inc, West Concord; MN LICA, Owatonna; Schumacher Construction, Zumbrota; Stu Frazeur Tiling, Canby; and Iowa LICA, Independence, IA.

Matejcek’s Implement, Faribault, MN, moved dirt to help build one of two water retention basins during the field days. They used a IH MX200 to pull a Reynolds scraper. Matejceks had added a ‘buddy’ seat in the cab of the tractor to allow contractors to ride along and observe the equipment in operation.

Leonard Binstock, Executive Director, MN LICA, has high praise for all the LICA members for their work and equipment, for associate members who donated supplies and equipment and for the cooperation and resources of the Southern Research and Outreach Center. “Everybody worked so hard on this show to make it the success that it was.” He reflects on the future impacts of the project by saying, “Many of the experts that visited the site feel that this facility will become the envy of other agricultural schools across the nation.”

Off to one side of the farm attendees saw research work on alternate surface inlets being carried on by Kristina Overson, U of MN graduate student - Water Resources. “Some farmers are already using ‘blind inlets’ of various kinds,” says Kristina. “But they’re concerned about how long the inlets will work and what are the best kinds to use. We want to find out what kinds will reduce the amounts of nitrogen being lost. Which ones will trap the most pollutants coming off a field. Which ones will last the longest and be the easiest to maintain.”

Dr. John Nieber, Professor, Dept. of Biosystems, U of MN, talks about the possibilities of planting ‘Driparian’ strips above tile lines to help cut down nitrogen losses. “Roots from the plants would take up nitrogen and keep it from being drained off in tile water.”

This could perform the same function as riparian strips next to watercourses that cut down losses of soil and nitrogen.

“There’s another intriguing possibility,” says Dr. Nieber, “of cutting down nitrate losses by tile water. This involves the introduction along tile lines of some material with a source of readily available carbon, such as straw mulch or wood chips. This barrier along each side of a tile line would chemically filter out nitrates from any groundwater flowing into the line.”

Answers A’Coming
No longer will folks whiz past the little 160-acre farm without giving it a second look as they have in the past. Instead, in the months and years to come, this will likely be the most looked at, studied and statistically-prized piece of farmland in southern Minnesota. For this, the Agro-Ecological Research Farm near Waseca will likely uncover and answer many heretofore hidden secrets about hydrology and water management that may ultimately change long used and widely accepted drainage practices.

Like its neighbors, its acres are now, for the first time ever, underlain by drain tubing. Corn and soybeans will be the main crops and there will be minimum tillage. But, unlike its neighbors, its lines of tubing are buried at varying depths and spacings. And the level of drainage is being controlled in one part of the field to keep more water closer to growing plant roots and to encourage more nitrogen uptake by the plants. All the varied systems, the blind inlet studies and the wetland management are aimed at improving the quality of drainage water, while economically increasing crop yields.

The MN LICA’s interest in AERF didn’t end when they returned home with their equipment last summer after installing the systems. Their efforts to support further research bore fruit in May, 2000, when a legislative bill that they authored was signed into law. The bill appropriated $300,000 in state monies to be used for research in Minnesota. Hopefully, answers from all the research will translate into improved and more effective drainage systems throughout the Midwest, ‘breadbasket of the nation’. L&W

For more information, contact Dr. Gary R. Sands, 209 Biosystems & Agricultural Engineering Bldg., 1390 Eckles Ave., St.Paul, MN 55108, (612)625-4756, fax (612)624-3005, grsands@umn.edu; or Dr. John Nieber, Dept of Biosystems and Engineering & Agricultural Engineering, U of MN, St. Paul, MN 55108, (612)625-6724, fax (612)624-3005, nieber@gaia.bae.umn.edu; or Leonard Binstock, Exec Dir., MN LICA, 1816 Hemlock Ave., Owatonna, MN 55060, (507)455-9179, fax (507)444-0465, MNLICA@LL.net.

©2000, 1999, 1998 Land and Water, Inc.
Thursday, November 30, 2000 - http://www.landandwater.com/features/vol44no3/vol44no4_2.html