Not A Drop More

Drainage water management holds back nitrate during the winter months

By Dean Houghton

Saving the Gulf of Mexico is a big job, but Indiana farmer Doug Mills needs only about five minutes each fall to do his part. That’s about how long it takes him to drop some polyethylene stoplogs into a drainage control structure.

Once in place, these mini-dams will significantly cut back the amount of water flowing from his tile drains during the winter months. Cutting back winter flow helps to reduce the amount of nitrate-nitrogen that escapes from the field and heads downstream. Nitrate contributes to the Gulf’s large area of hypoxia (low oxygen), often called the “Dead Zone.”

Fighting hypoxia. Mills is hosting a demonstration plot on his farm, allowing Purdue University researchers to compare a 26-acre field that has a drainage control system against an adjacent 34 acres, which is served by free-draining tile. Researchers keep
track of numerous variables, from rainfall, to height of the water table, and data is automatically fed from the site through a satellite link.

His fields are part of a five-state drainage-water-management demonstration program that includes 20 sites spread across Iowa, Illinois, Indiana, Minnesota, and Iowa. The program is coordinated by the Agricultural Drainage Management Coalition, and is funded by a Conservation Innovation Grant from the USDA’s Natural Resources Conservation Service.

Golden Rule. Leonard Binstock, ADMC’s executive director, weaves through the five states each year, holding field days at the demonstration sites. He shares the latest data collected from the contrasting systems, and also a philosophy about agricultural
drainage management that he calls the Golden Rule: “Drain only enough to ensure trafficability and crop production— and not a drop more.”

Drainage water management is the practice of using a water-control structure in a main, submain, or lateral drain to vary the depth of the drainage outlet. Managing the system is straightforward. Growers add stoplogs after harvest to reduce the delivery of nitrate to ditches and streams during the off-season. The outlet level is lowered again in early spring, and again in the fall, so the drain can flow freely before tillage and harvest operations. In summer, the outlet is raised to help store water in the soil profile for the crop to use during dry spells.

Binstock says that ADMC and its land-grant partners set up the demonstration sites to help answer a number of questions about how controlled drainage might affect a farm.

The questions are wide-ranging: Does the additional water in the soil profile during winter and summer months affect the earthworm population? (Probably not, according to a preliminary study.) Will additional pressure cause blow-outs in existing tile? (Not likely using commercially available control structure installed on shallow, gravity flow drainage systems.) Will drainage water management lead to tile plugging? (Probably
not, since the high flow rates used in spring and fall to drain the soil profile likely will flush any accumulated sediment from the tile system.)

Future flow. Controlled drainage systems typically are used only on flat fields, those with a slope of less than 1%. Binstock points out that new technologies may allow fields with considerably more slope to be fitted with a system. “There are a number of
new drainage management tools that are going to become available in the farmer’s toolbox,” he predicts.

In the meantime, Indiana farmer Mills is happy to take a little time to protect the Gulf. “We take a few minutes to lower the outlet in the spring, about three weeks before we start any tillage work, so the field will hold up to traffic,” he says. “The system seems to boost yields when moisture is short. We are seeing a lot of ways that managed drainage offers advantages.”

Planning an Agricultural Subsurface Drainage System

by Jerry Wright and Gary Sands

Copyright © 2001 Regents of the University of Minnesota. All rights reserved.

GENERAL CONSIDERATIONS

Many soils in Minnesota and throughout the world would remain wet for several days after a rain without adequate drainage, preventing timely fieldwork, and causing stress on growing crops. Saturated soils do not provide sufficient aeration for crop root development, and can be an important source of plant stress. That's why artificial drainage of poorly draining soils has become integral to maintaining a profitable crop production system. Some of the world's most productive soils are drained, including 25 percent of the farmland in the United States and Canada.

Planning an effective drainage system takes time and requires consideration of a number of factors, including:

• Local, state, and federal regulations
• Soil information
• Wetland impact
• Adequacy of system outlet
• Field elevation, slope (grade), and topography assessment
• Economic feasibility
• Present and future cropping strategies
• Environmental impacts associated with drainage discharge
• Easements and right-of-ways
• Quality of the installation

The U.S. Department of Agriculture (USDA) Food Security Act and the farm bills of 1985, 1990, and 1996 created many special wetlands restrictions and mandates that all drainage projects, including upgrades, must follow. It's also very important that the landowner, system designer, and contractor understand other applicable federal laws, as well as the local watershed and state laws dealing with drainage. People considering installation of a drainage system should also know their rights and responsibilities concerning the removal of water from land and its transfer to other land. So the first steps of any installation project should always include visits to the offices of the Soil and Water Conservation District (SWCD), the Natural Resources Conservation Service (NRCS), and the local watershed administrative unit.

While developing a drainage plan and specifications, it's useful to consult a number of information sources. These include county soil and site topography surveys, the Minnesota Drainage Guide1, local drainage experts, Farm Service Agency aerial photos, and ditch and downstream water management authorities. It's also a good idea to do some surface and subsurface evaluation of a field.

ECONOMICS

To decide whether a new drainage system (or improving an existing system) makes economic sense, it's necessary to determine or estimate the following: (1) what the crop response might be for the area to be drained, (2) the impact of a system on the timeliness and convenience of field operations, and (3) changes in inputs and other costs associated with a drainage system. Needless to say, it's not easy to estimate some of these factors. Data gathered from a combine yield monitor may offer good information on the yield range and variability of a field, as well as crop response to previous drainage activities.

Other potential sources for yield response information related to improved drainage include neighbors, county Extension educators, and the SWCD office. Many county soil surveys have also identified the potential yield for each soil type for common crops using sound management practices. A detailed financial analysis using the Ohio crop response information can be found in "Minnesota Farmland Drainage: Profitability and Concerns."6 A simplified on-line profitability analysis, developed by the University of Minnesota Extension Service, can be performed at the following website: www.prinsco.com/farm.cfm. Advanced Drainage Systems (ADS) also offers a CD version of a simplified profitability analysis for drainage investments. Contact your local dealer for more information. These simplified analyses can give you a first guess at overall profitability, but lack the sophistication required to fine-tune investment decisions.

SYSTEM CAPACITY and DRAINAGE COEFFICIENT

To protect crops, a subsurface drainage system must be able to remove excess water from the upper portion of the active root zone 24 to 48 hours after a heavy rain. (See Agricultural Drainage Publication Series: Soil Water Concepts, BU-07644-S, for more information on excess, or drainable, soil water.) The drainage system capacity selected for most northern Midwest farmlands should provide the desired amount of water removal per day, commonly referred to as the "drainage coefficient." This figure is often between 3/8 and 1/2 inch of water removal per day. Table 2 shows drainage coefficients guidelines for crop production for land that has adequate surface drainage. (The figures are from Chapter 14 of the NRCS Engineering Field Handbook).

Any refinement of these drainage coefficient guidelines should be done after consulting with drainage experts and local drainage contractors. NRCS literature suggests the drainage coefficient may need to be increased where one or more of these situations occur:

• The crop has high value (e.g., sugar beets or other vegetable/truck crops)
• Soils have a coarser texture
• Crops have a lower tolerance to wetness
• The topography is flat (implying poorer surface drainage)
• Large amounts of crop residue are left on a field
• There is little or poor surface drainage
• Crop evapotranspiration is low
• Frequent and low intensity rain is common
• Planting and harvest times are critical

TOPOGRAPHY and SYSTEM LAYOUT

Where it is necessary to convey surface water to the subsurface drainage system through surface inlets. NRCS literature suggests use of the drainage coefficients in the bottom half of Table 2, depending on inlet and soil type. The selected coefficient should be applied to the entire watershed contributing runoff to the surface inlet unless a portion of the runoff is drained by other means.

The goal of drainage system layout and design is to provide adequate and uniform drainage of a field or area. Field topography and outlet location/elevation are typically the major factors considered in planning drainage system layout, with topography greatly influencing what layout alternatives are possible. It's best to create a topography map of the field showing the elevations of the potential or existing outlet(s). A number of methods may be used to create the map, including standard topography surveys, a GPS or a laser system. The topography map helps the designer assess overall grade and identify the high or low spots in a field that might pose challenges.

The system outlet, whether an open channel or a closed pipe, must be large enough to carry the desired drainage discharge from a field quickly enough to prevent significant crop damage. Drainage outlets are typically located three to five feet below the soil surface. Sometimes pumping is required to create an adequate outlet. The bottom of an outlet pipe should be located above the normal water level in a receiving ditch or waterway. It is expected that floods or high water levels may submerge the outlet briefly. Drainage outlets must be kept clean of weeds, trash, and rodents. Outlets must also be protected from erosion, damage from machinery and cattle, and ice in flowing water.

Although there may be many possible layout alternatives for a given field (see Figure 1), specific drainage goals should be evaluated to find the best layout. These goals include removing water from an isolated problem area, improving drainage in an entire field, intercepting a hillside seep, and so on. Farmers and designers should approach system layout and drainage needs in a broad, comprehensive manner, anticipating future needs where possible. Even if a drainage system is installed on an incremental basis -- some this year, more next year, and so on -- system planning should not be piecemeal. Additions to a system will be much easier to make if the established mains are already large enough and located appropriately.
Fig. 1. Various drainage system layout alternatives.

DRAINAGE SYSTEM LAYOUT

When selecting a layout pattern for a particular field or topography, lateral drains, or field laterals, should be oriented with the field's contours as much as possible. This way, laterals can "intercept" water as it flows down-slope. Mains and submains (also called "collectors"), on the other hand, can be positioned on steeper grades, or in swales, to facilitate the placement of laterals.

DRAIN DEPTH and SPACING

A close relationship exists between soil permeability and the recommended spacing and depth of drains. When a system of parallel laterals is used, the drain spacing and depth should be considered simultaneously, based on soil type, soil permeability and stratification, the crops to be grown, the desired drainage coefficient, and the degree of surface drainage. If there is an abrupt transition from lighter to heavier soil, it's better to keep the drains above the heavy layer, when possible. Spacing drains closer together results in a higher drainage coefficient and faster drainage. The answer to the question "How close is close enough?" involves balancing costs and benefits. Simply stated, the increased cost associated with narrower drain spacings can only be justified to a point. After that, the only result is decreasing profits.

An ideal drainage system would have a uniform drain depth. In the real world, topography and system layout determine the actual depths of drains. A system layout that matches poorly with field topography will result in a wide variation of drainage depths and uneven field drainage. Avoid a system layout with many points of minimum cover (2 - 2-1/2 ft) and excessively deep cuts.

Make decisions on drain spacing and depth after consulting NRCS literature and talking to people in the area with drainage experience. Table 3 shows the most general spacing and depth options that might be considered during the early planning phase of a new or improved system.

DRAIN SIZING

The maximum amount of water a drainage pipe can carry (its capacity) depends on the pipe's inside diameter, the grade or slope at which it's installed, and what the pipe is made of (e.g., smoother pipe has a greater flow capacity, all else being equal). Typically, full-flow pipe capacities for specific grades, pipe sizes, and pipe materials can be obtained from a number of sources:

Manufacturers' literature

• Nomographs (charts) in the Minnesota Drainage Guide1
• Pocket slide charts available from companies such as Prinsco, ADS, and Hancor
• On-line calculators (d-outlet.umn.edu or www.prinsco.com/farm.cfm)
• Local drainage contractors and engineers

To estimate the required flow capacity (Q) in cubic feet per second (cfs), multiply the area to be drained by the desired drainage coefficient (dc) and divide by the conversion factor (23.8).

Q(cfs) = area (acres) x dc (inches/day)
____________________________________
23.8

(To use the equation in this form, area and dc must be in units of acres and inches/day, respectively.) Once Q is determined, pipe grade, material, and (ultimately) diameter can be selected to provide the required flow capacity. Topographical constraints typically determine pipe grade, so the pipe size is determined after the material is selected (e.g., corrugated polyethylene pipe, smooth interior pipe, etc.).

Besides flow capacity, drainage systems should also be designed to provide a certain minimum velocity of flow so that "self-cleaning" or "self-scouring" takes place. Where fine sands and silt are present, the minimum recommended velocity is 1.4 feet per second to keep sediments from accumulating in the system. Drainage systems in more stable soils can tolerate slower flow velocities, as low as 0.5 feet per second. Table 4 shows the minimum grades recommended for various pipe sizes when using these flow velocities. These grades are supported by the American Society of Agricultural Engineers -- ASAE EP260 standards. Flatter grades result in slower flow and run the risk of failure, and reverse grades, of course, must always be avoided.

Example: Find the flow capacity needed to drain 80 acres with a 1/2 inch/day drainage coefficient:

Q(cfs) = 80 ac x 0.5 in/day divided by 23.8 = 1.7 cfs

Because excess water velocities could cause some pressure problems at drain joints or tube openings that might result in unwanted erosion of the soil around the drain, there are also suggested maximum grades for drain sizes and soil types. These suggestions are outlined in Chapter 4 of the Minnesota Drainage Guide1.

When computing drain size with any tool or chart, always round an intermediate size to the nearest larger commercially available size. For example, if a calculation calls for a 6.8-inch diameter pipe, select an 8-inch pipe, assuming a 7-inch pipe is not available.

USE OF DRAIN ENVELOPES (SOCKS)

A drain envelope, or "sock," is a material placed around a drain pipe to provide either hydraulic function, which facilitates flow into the drain, or barrier function, which prevents certain sized soil particles from entering the drain. Drain envelopes are not filters. Filters become clogged over time; drain envelopes do not. Many types of envelope material exist, from thick gravel and organic fiber to thin geotextiles. The useful life of a synthetic drain envelope is quite long, provided it is not left in the sun for a long time and exposed to too much ultraviolet radiation.

Fine-textured soils with a clay content of 25 to 30 percent are generally considered stable, so they don't need drain envelopes. A geotextile sock is recommended for coarse-textured soils free of silt and clay. These soils are considered unstable even if undisturbed, so that particles may wash into pipes. The need for an envelope in intermediate soils (clay contents less than 25 to 30 percent) is best left to a professional contractor or soil and water engineer because soil movement is more difficult to predict.

ENVIRONMENTAL IMPACTS

Subsurface tile drainage systems can convey soluble nitrate-nitrogen (N) from the crop root zone. Implementation of nitrogen fertilizer Best Management Practices (BMPs) can reduce the potential loss of nitrate-N. Adding perennial crops to the rotation may also reduce N losses to surface waters in addition to decreasing water drainage. Farmers installing new or improved field drainage systems should consider using crop management practices and landscape structures that reduce nitrogen, sedimentation, and water discharge rates.

SURFACE INLETS (INTAKES)

Surface inlets remove ponded water that forms in closed basins or potholes in a field. These inlets, however, can provide a direct pathway for surface waters that may carry sediment and other pollutants to drainage ditches and other downstream surface water. The general public, resource managers, and others are concerned about the potential impacts of surface inlets to both the quality and quantity of downstream waters.

From a water quality perspective, almost any inlet configuration is preferable to using an open pipe that's flush with the ground surface. Of the traditional intakes available, the slotted or perforated riser is a good option because it promotes some settling of sediments in the basin during flow events.

Farmers in some areas have begun replacing traditional inlets with "blind" or "rock" inlets. These have the advantage of being farmable, and anecdotal evidence suggests they can remove water effectively. There are still questions, however, about the effective life of rock inlets. University of Minnesota researchers are currently investigating the performance characteristics of these and other alternative surface inlet designs. This work will ultimately lead to a better understanding of their effectiveness and longevity.

NSTALLATION QUALITY

A great deal of careful consideration goes into installing a drainage system. Drain depth, grade, pipe size, and field layout are all extremely important design factors that will determine how well a system performs. But the installation method is also key to a successful system. It's why special care should be taken to ensure that every installation is on grade and of high quality.

Because quality installation is important, an experienced installer is usually an asset. It's also important to know the limitations of equipment. Although pull-type and tractor-mounted drainage plows or trenchers can often perform adequately, they face limitations in the field that, when improperly accounted for, can result in installation and performance problems. Field irregularities such as dead furrows, lines, swales and rocks can pose installation problems for these machines. In addition, operators have found it difficult to make cuts deeper than five feet.

SUMMARY

Improved surface and subsurface drainage is necessary for some Minnesota soils to optimize the crop environment and reduce production risks. To assure an effective and profitable system, it's important to couple a good design process with the thorough evaluation of suconion on-site factors as soil type, topography, outlet placement and existing wetlands. This, and a quality installation will ensure a drainage system that will perform effectively for many years to come.

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,