NORTHERN CORNBELT SAND PLAIN
MINNESOTA	NORTH DAKOTA	SOUTH DAKOTA	WISCONSIN

Minnesota's Management
Systems Evaluation Area

Bruce Giebink

Copyright ©  2009  Regents of the University of Minnesota. All rights reserved.

What is MSEA?

The Management Systems Evaluation Area (MSEA) Program exists in the five midwestern states of Minnesota, Nebraska, Iowa, Missouri and Ohio. One primary program goal is to evaluate the impact of prevailing agricultural management systems on water quality. Its other goal is to develop new crop management systems that should lessen agricultural impacts on water quality, and then evaluate the abilities of those new systems to protect the quality of our ground water resources.

Minnesota's MSEA project, the Midwest Initiative on Water Quality: Northern Cornbelt Sand Plain, covers four research sites on sand plain areas of the region. The main research site is on the Anoka Sand Plain in east central Minnesota, at Princeton. The three satellite sites are in southeast North Dakota at Oakes, east central South Dakota at Aurora, and south central Wisconsin at Arena.

Why was this MSEA research project started?

MSEA is a response to growing concerns about the nutrients and pesticides being detected in our water supplies. While we have considerable information on the contaminant levels of these agricultural chemicals, we as yet know very little about how these materials reach the ground water. Minnesota's MSEA project is an attempt to fill this information gap for the sand plain areas of the northern cornbelt.

Who is involved in this MSEA project?

The MSEA project is coordinated through the university's Center for Agricultural Impacts on Water Quality at the University of Minnesota.

MSEA research involves many federal and state agencies. These include: the state agricultural experiment stations and extension services of Minnesota, North Dakota, South Dakota and Wisconsin; the Agricultural Research Service; the Cooperative State Research, Education and Extension Service (CSREES, which incorporates both the former Cooperative State Research Service and the former Cooperative Extension Service); the Natural Resource Conservation Service; the Economic Research Service; the U.S. Geological Survey; the U.S. Environmental Protection Agency; and the Minnesota Pollution Control Agency.

Why were the MSEA project sites located in the Midwest?

The mid-continental corn belt was selected for study because this area uses about 60 percent of the nation's pesticides and nitrogen fertilizers to produce about 80 percent of the nation's corn and soybeans.

Why was Princeton selected for Minnesota's MSEA site?

Highly permeable, low fertility soils overlying shallow aquifers make balancing agriculture and the environment a challenge. This is especially true for intensively managed crops such as potatoes. The Princeton site fits this profile and:

• allows us to evaluate impacts of farming systems within the short five-year project time frame;



• has many local agencies already actively involved at the site with the Anoka Sand Plain Water Quality Demonstration Project;



• is relatively isolated from other agricultural activities that might effect its data, by the Sherburne Wildlife Refuge to the west and by Battle Brook to the north and east, and is relatively pristine by agricultural standards;



• is a two aquifer setting, where effects on the surficial aquifer should not effect the confined aquifer below.

What are the objectives of Minnesota's MSEA project?

The primary objective of Minnesota's MSEA project is to evaluate the effects of irrigated agricultural management systems on ground water quality in the surficial sand and gravel aquifers underlying much of the four states. As these impacts are measured, the second project objective comes into play: modifying current systems or developing alternatives to reduce any adverse effects.

Specific objectives of the Minnesota MSEA project are to:

• measure the effects of ridge-tillage practices in a corn-soybean system on transport rates of the herbicides atrazine, alachlor (Lasso) and metribuzin (Sencor) in the soil and aquifer;



• determine the effects of nitrogen fertilizer management on water quality;



• characterize water flow and relate it to the transport of agricultural chemicals;



• determine the relationship between ground water recharge and agri-chemical loading of ground water.

What cropping systems are being evaluated in this MSEA?

Three cropping systems are being evaluated at the Princeton site: a ridge-tillage corn-soybean rotation, continuous corn, and a potato-sweet corn rotation.

Each rotation system is paired so that both crops of the system are present every year.

A ridge-till corn-soybean rotation is the main cropping system being evaluated. It is a modified system that uses ridge-tillage, banded applications of atrazine and Lasso on corn, Lasso and Sencor on soybean, split nitrogen applications, and a checkbook system to schedule irrigation and minimize leaching. Ridge tillage was chosen for this evaluation because it provides a nearly ideal water flow system for sidedress N fertilizer and band-placed herbicides. In this system, less water infiltrates and flows through the ridge than in the furrow.

The continuous corn system, representing a more conventional cropping system, serves as a comparison and research control. It uses full width tillage, split applications of nitrogen fertilizer, broadcast applications of atrazine and Lasso, and irrigation scheduling.

The potato-sweet corn rotation represents a high input, more intensively managed crop system. It uses full width tillage, split applications of nitrogen fertilizer, banded applications of atrazine and Lasso on sweet corn, broadcast applications of Dual (metalochlor) and Sencor on potatoes, and irrigation scheduling.

This drawing shows the layout of the Minnesota Management System's Evaluation Area site at Princeton, Minnesota. The five cropped areas consist of four 4.4 acre management blocks (A-D) and one 6.5 acre block (E). Areas A and C represent both phases of the sweet corn-potato rotation. Areas B and D represent both phases of the field corn-soybean rotation. These paired arrangements allow each phase of each rotation to be present every year.

There are 36 wells installed at the site: 22 multiport wells and 14 observation wells. Multiport wells monitor ground water flowing into, beneath and out of the five cropped areas at five different depths in the aquifer. Observation wells are used to sample ground water at depths of 10- to 14-feet. These wells are sampled throughout the year to provide background levels for ground water quality.

The management blocks and multiport wells are oriented parallel to the direction of ground water flow. Ground water moves into the left sides of the blocks, out the right sides, and eventually discharges into Battle Brook and surrounding wetlands.

The research area is located on the Anoka Sand Plain near Princeton, Minnesota, about 50 miles northwest of Minneapolis.

What kind of information is the MSEA project collecting and evaluating?

Weatheris monitored hourly at Princeton by an automated weather station. Additionally, a regional rain gauge network and throughfall precipitation collectors record total precipitation and its distribution between the row.

Soil is sampled at varying depths six times a year, from preplanting to post-harvesting. Soil moisture is measured with Time Domain Reflectometry and neutron access probes. Thermocouples track wetting fronts and shaft encoders monitor water level fluctuations. Suction lysimeters measure nitrate-N at various soil depths.

Ground water is sampled four times per year (at thaw, planting, June-August, and post harvest) with a network of 22 multi-level water samplers. Other observation wells provide additional background information. Samples are analyzed for Atrazine and alachlor (Lasso) and their daughter products, and for Metolachlor (Dual) and nitrate-N.

Crop biomass is being sampled at three growth stages.

What have MSEA researchers found out so far?

Regarding farming systems influence on herbicide movement:

• Banded applications of atrazine, alachlor (Lasso), and metribuzin (Sencor) in a ridge-till, corn-soybean farming system have been found to not degrade ground water quality.



• Overlapping ammonia fertilizer (anhydrous ammonia, urea) and atrazine applications can increase atrazine movement into ground water in some areas (such as at the South Dakota site).

Regarding nitrogen management:

• In a ridge-till, corn-soybean rotation, nitrogen additions have not degraded ground water; nitrate-N concentrations in the ground water seldom exceed 20 ppm and appear to be decreasing.



• In potato-sweet corn rotations, nitrogen additions (at 1.4 times the N rate of corn) have degraded ground water. Nitrate-N concentrations have steadily increased from background levels of 6 to 20 ppm (1991) to between 30 and 35 ppm (1993).



• Placing nitrogen fertilizer in the ridge reduces leaching and increases use efficiency.



• If nitrogen fertilizer is applied in a band over the ridge, sampling three inches from the band gives you the best estimate of nitrogen needs.



• Areas of similar yield change from year to year on this soil type, making variable rate fertilizer applications difficult.



• Crop yields varied up to 15 percent each year.

Regarding water movement and use:

• After a 2-inch rain, water at the Wisconsin site moved down six feet in 12 hours. This didn't happen at the Minnesota site because numerous soil layers retarded drainage.



• Due to low water retention, nitrogen uptake and yield are lowest on backslopes. Higher water retentions on lowland locations produce much higher nitrogen uptakes and yields



• Corn used more water than soybean every year.



• A tool for evaluating management alternatives, the Root Zone Water Quality Model, predicts water and chemical movement fairly well early in the growing season, but less so late in the season.

How does this research benefit agriculture?

There are at least three major benefits coming from the MSEA project. This research may:

• Help keep farmers on the sand plain in business. Developing additional management tools and options, such as irrigation scheduling and nitrogen placement recommendations, and in-season nitrogen monitoring tools can provide farm producers with a larger range of production choices. And if MSEA research objectively shows that agriculture can be compatible with preservation of ground water quality in a sensitive area, less regulation and more finely tuned management systems should help local producers remain profitable and in business, especially growers with input intensive crops such as potatoes.



• Help shape, possibly minimize further regulation. Agricultural chemical dealers and farm producers operating on sand plains need policies and regulations that effect them to be based on relevant, factual data specific to sand plain conditions. This is especially true for questions relating to the transport and movement and crop utilization of agri-chemicals under those conditions. Without such unbiased data, regulatory actions related to chemical use could be easily made more stringent than necessary.



• Contribute to the development of more environmentally sound agri-chemicals. Many factors affect how much and how quickly any particular chemical moves through soil and gets into the ground water. Research on sandy soils improves our understanding of how soil, water, chemicals, and management systems interact. Agri-chemical manufacturers can apply such information to the design of their products, and extension educators and farm advisors can apply this knowledge to recommendations for farm production management strategies.

How can I get more information?

To obtain other MSEA project fact sheets, or if you have questions about the project, contact:

Bruce Giebink
MSEA Education Coordinator
Department of Soil Science
452 Borlaug Hall
St. Paul MN 55108
phone: 612 / 625-4749
email:bgiebink@soils.umn.edu

Production and editing by Larry A. Etkin. Diagram of Princeton site is by Jeff Delane.

Produced by Communication and Educational Technology Services, University of Minnesota Extension.

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