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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