Farming systems : impact on water quality : Management Systems Evaluation Areas (MSEA) progress report 1994

18 Pages·1995·1.4 MB·English

by  United States. Agricultural Research Service

Historic, archived document
Do not assume content reflects current
scientific knowledge, policies, or practices.

—
United States Farming Systems;.
Departmentof
Agriculture
Impact on Water
Agricultural
Research
oOearviitacea
Quality
ARS-135
Management Systems
Evaluation Areas (MSEA)
Progress Report 1994
Report of the MSEA Program of the
United States Department of Agriculture
Agricultural Research Service
Cooperative State Research, Education, and
Extension Service
Natural Resources Conservation Service
United States Geological Survey
United States Environmental Protection Agency
U.S. Department ofAgriculture, Agricultural
Research Service. 1995. Farming Systems:
Impact on Water Quality. Management Systems
Evaluation Areas (MSEA) Progress Report 1994.
U.S. Department ofAgriculture, Agricultural
Research Service, ARS-135.
While supplies last, single copies ofthis publica-
tion are available from:
Dale Bucks, National Program Leader, Water
Quality and Water Management
Room 233C, Bldg. 005. BARC-West
10300 Baltimore Ave.
Beltsville, MD 20705
Copies ofthis publication may also be purchased
from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
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Issued August 1995
Water Quality Problems in the Midwest ern States. Madison and Burnett (1985) found
that 6.4 percent ofthe 123,656 wells sampled
throughout the Nation had nitrate concentrations
The Midwestern United States is the location of greater than 10 mg/L and 13 percent between 3
the world’s most intensive agricultural production mg/L and 10 mg/L. Nitrate moves through the
system, which tends to use a large amount of
soil profile with the percolating water and can
agricultural chemicals. Over 80 percent ofthe
leach below the root zone unless taken up by
corn and 70 percent ofthe soybeans produced in
the United States are grown in the Midwest. To plants. Mueller et al. (1993) found that nitrate
concentrations in the surface waters of the
produce these crops requires 58 percent ofthe
Midwest were related to streamflow at the time of
nitrogen fertilizer (EPA 1990) and over 60 percent sampling, acreage ofthe basin in com, acreage in
ofthe herbicides (Gianessi and Puffer 1990) used soybeans, and density ofboth cattle and human
in the United States. These agricultural chemicals
populations.
are applied on more than 96 percent ofthe Mid-
west land area planted to com and soybeans
Recent herbicide monitoring efforts at nine
(USDA 1993). In 1992, the top five pesticides used
in com production in the United States were different surface water sites within the Missis-
sippi River Basin by the U.S.Geological Survey
atrazine on 69 percent ofthe corn acres planted,
for 1989 and 1990 revealed large amounts
metolachlor on 30 percent, alachlor on 27 percent,
dicamba on 2 percent, and cyanazine on 20 (pounds ofherbicides) during the first runoff
1 after herbicide application. Atrazine was detected
percent (USDA 1993). For soybeans, the top five
in 100 percent ofthe surface water samples for
pesticides in use for 1992 were trifluralin on 35
the April 1991 through March 1992 period
percent, imazethapyr on 29 percent,
(Goolsby and Battaglin 1993). The average
pendimethalin on 21 percent, imazaquin on 18
concentrations ofatrazine before planting and
percent, and ehlorimuron-ethyl on 17 percent
(USDA 1993). All these pesticides are herbicides application were less than 1 pg/L and increased
to 3.8 pg/L after planting in the 132 streams
used for weed control.
sampled during this time. The atrazine concen-
trations in the surface waters were related to the
There have been several efforts in recent years to increase in streamflow. The amount ofatrazine
measure the quality ofthe surface and ground
lost from the Mississippi River basin to the Gulf
waters ofthe United States. The U.S. Geological
ofMexico is small and represents less than 3
Survey (USGS) sampled aquifers within 15 meters
percent ofthe amount applied within the basin.
(50 feet) ofthe land surface throughout the Mid- Nitrate losses, however, may represent closer to
west and screened each sample for detection of
any herbicide and nitrate-nitrogen (Burkart and 15 percent ofthe amount applied within the
basin.
Kolpin 1993). Herbicides were found in 24 percent
ofthe 579 wells sampled. The most frequently
detected compound was the atrazine metabolite Ground water is the primary source ofdomestic
water in most ofthe Midwest. Surface water
deethylatrazine followed in order by atrazine,
supplies from lakes and reservoirs account for
deisopropylatrazine, prometron. metolachlor,
less than 10 percent ofthe drinking water within
alachlor. metribuzin, simazine, and cyanazine. these States. The MSEA (Management Systems
The reported concentrations for all compounds Evaluation Areas) program was developed to
were less than 0.5 pg/L (1 microgram per liter understand the linkages between farming prac-
eeqxucaelesdi1ngpatrhtep1e.r0b,iulgl/iLon()1 wpiptbh) amafexwismaummplceosntami- tiincgesthaensdywsatteemrfqruoamliatpypilnictahteioMnidtowetsratnsbpyorstt.udy-
nation limit (MCL) (Burkart and Kolpin 1993).
Herbicides found within the samples were among
Herbicide and nitrate detections in surface and
those extensively used throughout the Midwest. In
ground water have prompted concern about the
this study, the herbicide prometron was found in
pathway ofmovement from different farming
wells sampled near residential land or golf
practices in the surface and ground waters ofthe
courses, indicating that herbicides used for Midwest. The MSEA program was formed with a
nonagricultural purposes could also enter the
goal to identify and evaluate agricultural man-
aquifers.
agement systems that can protect water quality
in the Midwest. This progress report will describe
Nitrate has been found in shallow ground water the efforts ofthis program to understand how
samples in the Midwest. Burkart and Kolpin
(1993) found nitrate-nitrogen above the 10 mg/L different farming practices affect surface and
ground water quality.
(1 milligram per liter equals 1 part per million)
MCL
in 6 percent oftheir samples. Detections
above 10 mg/L (10 ppm) vary among the Midwest-
1
Within USDA, leadership for the MSEA program
Management Systems Evaluation is provided by ARS and CSREES in close coop-
Areas eration with SAES as well as NRCS. ARS and
CSREES are conducting a major portion ofthe
research on developing better techniques and
MSEA brings together scientists, educators, and methods for managing land use, soil, water,
technical assistance specialists from a variety of nutrients, and pests. Investigators within SAES
public sector and academic settings in an inte- and other university scientists, in cooperation
grated. multiagency program that is built on with ARS, conduct research to address needs for
unity ofpurpose. The research is cooperatively different management systems throughout the
conducted by Federal. State, and university Midwest. ARS. CSREES, SAES, and NRCS work
scientists; planning, evaluation, and oversight together to make the results available quickly to
are managed by interagency groups. other agencies. The USGS Mid-Continent Herbi-
cide Initiative provides expertise on geology,
The MSEA program is a cooperative endeavor hydrology, and ground water movement. EPA. as
among the U.S. Department ofAgriculture's part ofthe MASTER project, leads the effort to
Agricultural Research Sendee (ARS), Cooperative assess agricultural effects on ecosystems and
State Research. Education, and Extension Ser-
ecosystem protection.
vice (CSREES), and Natural Resources Conserva-
tion Service (NRCS); State agricultural experi- The MSEA program was developed around six
ment stations (SAES); and the U.S. Geological general objectives to address the program goal.
Survey. The U.S. Environmental Protection The objectives ofthe program are to:
Agency (EPA) has become a participant in the
MSEA program through the MASTER (Midwest • Measure how prevailing and modified farming
Agrichemical Surface/Subsurface Transport and
systems affect the content of nutrients and
Effects Research) project. Several State agencies pesticides in ground and surface waters.
are involved in each ofthe participating States
throughout the Midwest. Five projects with a
total of 10 sites are locations (fig. 1) within the
MSEA program.
Atthe Walnut Creekwatershed in central Iowa, technician samples surface runoff and waterflowing out oftile
lines underfarm fields to measure pesticide and nitrate levels (92BW1863-25).
2
• Identify and increase understanding ofthe • Models and decision-aid systems enable
factors and processes that control the fate scientists to better account for processes that
and transport ofnutrients and pesticides. take place when water moves through the soil
or runs offthe surface. Some ofthe processes
• Assess how nutrients, pesticides, and agricul- evaluated include: rates ofwaterflow through
tural production practices affect ecosystems macropores, effects oftillage and residue
associated with agriculture. cover on movement ofwater and chemicals,
dynamics ofherbicide degradation, nitrogen
• Assess projected benefits and costs ofimple- cycling and transformations, and evaluation
menting modified farming systems in the ofplant growth and water uptake patterns.
Midwest.
• Effects ofagricultural practices on ecosys-
• Evaluate the social and economic effects of tems are tracked to enable prediction ofhow
modified management systems. agricultural practices affect ecological re-
sources. Information on the fate and trans-
• Transfer appropriate technology for use by port ofagricultural chemicals (fertilizers and
the farming community. pesticides) in subsurface and surface waters
is integrated with information on how agricul-
MSEA brings together the scientific expertise tural practices affect entire watersheds.
needed to address concerns about current farm-
ing systems and non-point-source pollution • Socio-economic factors such as profitability,
through a variety ofapproaches and at several effects on vendors, convenience, and eco-
sites. Field studies are conducted at many sites nomic incentives play an important role in
to address these objectives. Combined with the choice ofmanagement practices. Farm-
detailed laboratory studies directed toward level evaluations ofmodified farming systems
understanding the mechanisms ofnitrogen and are conducted, not only to assess how well
pesticide movement and evaluation oftechniques they protect surface and ground water, but
for determining the nutrient status ofsoil and also to learn whether they are accepted by
plants, the MSEA program blends the basic and farmers in different areas.
targeted research toward better agricultural
systems.
Since the MSEA program has the capability to
study the entire system, separate research
projects address a wide range ofissues related to
surface and subsurface water quality. Some
examples are:
• Farming systems are customized to regional
and local conditions. Unique combinations
representing the most appropriate farming
systems are evaluated at many sites.
• Management systems are compared to deter-
mine which are most environmentally sound.
Water samples are collected in all parts ofthe
hydrologic system and analyzed for alachlor,
atrazine, metolachlor, metribuzin, and other
herbicides, as well as nitrate and phospho-
rus. These are the most common agricultural
chemicals used in the production ofcorn and
soybeans in the Midwest.
• Data quality is a high priority for the pro-
gram. Rigorous protocols have been devel-
oped for collecting samples and recording
data. Analyses ofall water quality samples
within the MSEA program are verified by an
independent laboratory.
3
MSEA Research Locations and aquifer materials ofthe Midwest. Aquifers
represented in the MSEA program are significant
sources ofwater for public use and consumption
Rdiefsfeearerncthpirsojceocntdsuwcittehdinatth1e0MsSitEesA(fpirg.o1g)rfarmo.m five (USGS 1984). More than 70 percent ofthe popu-
lation ofIowa, Minnesota, Nebraska, South
These sites cover a wide range ofthe soils and
Dakota, and Wisconsin are served by aquifers
hydrogeology ofthe Midwest. Table 1 describes studied in this program. Alluvial valley aquifers
soil and aquifer materials for the sites.
supply water for major cities in Indiana, Iowa,
Missouri, Nebraska, and Ohio. Nutrients and
Sites where intensive research is being con-
pesticides will respond differently at each of
ducted represent a wide range ofsoils and aqui-
these sites. Three sites involve watershed-scale
fer materials, about 20 percent ofthe land area
research: Treynor and Walnut Creek, Iowa, and
Goodwater Creek, Missouri. The other sites are
field-scale research areas located within a por-
tion ofa watershed.
Organic carbon content ofthe soil is a major
factor in movement ofnutrients and herbicides
through the plant root zone and into the vadose
zone (depth of soil between where the plant roots
grow and the ground water table). Organic
carbon content ranges from less than percent
1
in the sandy soils ofthe Anoka sand plain to over
4 percent in the glacial till soils ofcentral Iowa.
The NRCS National Soil Survey Laboratory has
characterized each ofthe sites for its hydraulic
properties to quantify the rate ofwater movement
through the soil, the soil structure and texture,
and the general soil characteristics. These char-
acterizations help relate information collected in
these studies to other sites in the Midwest.
Table 1. Locations and descriptions of the soil and aquifer materials for MSEA sites
Location Surface Soil Aquifer Material Aquifer Name Depth to
Material Aquifer
Treynor, IA Silt loam Loess/sandstone Loess/Pennsylvanian 30 m
Nashua, IA Loam Carbonate rock Silurian-Devonian 60 m
Walnut Creek, IA Clay loam Sand and Skunk River Alluvium/ 100 m
gravel/sandstone Mississippian
and carbonate rock
Princeton, MN Loamy sand Loamy sand over Anoka Sand Plain 3-4 m
sand
Oakes, ND Sandy loam Loamy sand to gravel Oakes 3 m
Aurora, SD Silt loam Gravel Big Sioux 4-7 m
Arena, Wl Sand Sand Wisconsin River Sand 3 m
Plain
Centralia, MO Silt loam with Silty clay Glacial Drift 0.5-5 m
a claypan
Shelton, NE Silt loam Silt, sand, gravel Quaternary Deposits 4-5 m
Piketon, OH Silt loam or Sand and gravel Scioto River Valley 2-3 m
silty clay loam
4
Monitoring Activities practice represent the conditions under which
the study was conducted, and samples are
collected according to strict protocols. Laboratory
Monitoring activities began at all sites in 1990, methods for determining concentration ofherbi-
and the installation ofequipment was completed
cides and nitrate are continually checked against
in 1991. Extensive networks ofshallow and deep an external laboratory and among sites to main-
wells from which water samples are collected
tain a high degree ofconfidence in the results.
quantify the movement ofthe herbicides and
nitrate below the root zone. Shallow lysimeters
At the watershed sites, surface runoffis collected
placed within several farming systems intercept
from both fields and plots, and stream monitor-
free water moving in preferential flow paths to
ing permits an assessment ofthe surface water
characterize herbicide and nitrate movement
quality from an agricultural area. Soil water
around and through the root systems ofcrops
during the growing season. A series ofsingle-port conditions measured in the root zone permit
investigators to understand the dynamics ofthe
or multiport wells installed at each site permit
water balance. These measurements allow for
investigators not only to collect a sample for
estimating water use by the different farming
analysis, but also to determine the rate and
systems and evaluation ofwaterflow models that
direction ofwater movement to and within the estimate how nutrients and herbicides move
aquifer. Analyses oftritium, nitrogen species,
through the root zone during the year.
and minerals within the wells are used to deter-
mine the age ofthe water at different depths and
Crop grain yield and weed control are two pri-
the processes influencing water quality as water
mary factors used to determine response to each
moves through the vadose zone to the aquifer.
farming system. Nitrogen contents ofthe plant
and soil are measured in each farming system to
dCeovnesliodpeirnagblperoecffeodrutrheassfboreetnhedmiroencitteodritnogwaorfd determine how it can be more effectively used by
the crop. Several techniques to monitor nitrogen
herbicides and nitrate in the ground water.
MSEA investigators have worked to ensure that requirements are being evaluated over the differ-
ent locations to provide potential methods for on-
the data collected from each site and farming
farm application.
At an Ohio site near Piketon, scientists and graduate students accumulate information to monitor nutrients and
pesticides in multiport and conventional wells (93BW1679-34).
5
Farming Systems Within the MSEA nicosulfuron are being applied for weed control.
Program Several observations have been made from these
farming practices.
A corn-soybean rotation is the primary cropping Iowa studies revealed that surface runoffevents
system ofthe Midwest and is being examined at shortly after application caused concentrations of
all five MSEA projects. Variations ofnitrogen atrazine and metolachlor to exceed 80 mg/L. But
management and weed management are evalu- when surface runoffevents did not occur until 60
ated at the different sites; however, sites differ days or later after application, no increase in
because local practices are dictated by climate, stream concentrations were observed.
soil, landscape, and tillage practices. At each
site, an effort was made to use a realistic system In many areas that are intensively tile-drained,
practiced by the farmers as a basis for compari- atrazine moves to the tile through the soil profile.
son to other systems. Comparisons are being Concentrations increase in the tile drainage
made among systems to determine how changes water with increased flow; however, the concen-
in fertilizer and herbicide management will affect trations do not exceed 3 pg/L (fig. 2). The same
water quality. concentration-flow relationship applied to a
single field, a sub-basin ofthe Walnut Creek
Tillage practices being studied at the research watershed, and the entire watershed.
sites are shown in table 2. Each tillage practice
represents a herbicide, fertilizer, and crop rota- Streamflow studies in Missouri showed that
tion typical for the area for the different climates atrazine concentrations from the Goodwater
and soils that exist at the various locations. Creek watershed vary over seasons, with the
Atrazine, alachlor, cyanazine, metribuzin, and highest concentrations occurring during May
metolachlor are the primary herbicides studied in and June as shown in figure 3. Some atrazine
the MSEA program. In some no-till systems, the metabolites have been detected year-round.
postemergence herbicides imazethapyr and
14
MSEA 12
Table 2. Tillage practices at
10
research sites
8
6
Tillage Practice Sites Locations
4
Moldboard Plow 1 Nashua, IA 2
0
Chisel Plow 4 Nashua, IA 200
(liters/min)
Walnut Creek, IA
MO 150
Centralia,
OH
Piketon, 100 Rate
50
Ridge-Tillage 8 Treynor, IA
Nashua, IA 0 Discharge
Walnut Creek, IA 16000
MN
Princeton,
12000
Oakes, ND
OH
Piketon, 8000
Aurura, SD
Arena, Wl 4000
0
No-Till 4 Nashua, IA “'183 193 203 213 223 233 243
Walnut Creek, IA Day of Year- 1992
MO
Centralia,
OH
Piketon, Figure 2. Atrazine concentrations (lines) versus discharge
rates (squares) at three different sites (field, 8.9 ha; sub-
Disk and Till-Plant 1 Shelton, NE basin, 366 ha; watershed stream channel, 5,130 ha) within
Walnut Creek, Iowa, during July to August 1992.
6