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Geology and Water
Data Resources



Eric A. Palas
Department of Agronomy, Iowa State University, Postville, Iowa
Jeff Tisl
Natural Resources Conservation Service, Elkader, Iowa


The Sny Magill Watershed Project is an interagency effort to improve water quality through voluntary changes in farm management practices. The project provides technical assistance, information and education, and cost share assistance to producers within a 22,780-acre agricultural watershed. The project is designed to reduce sediment, nutrient, and pesticide delivery to Sny Magill Creek, a coldwater trout stream located in Clayton County, Iowa (Figure 1).


  Figure 1. Sny Magill Creek, Clayton County, Iowa.


Since 1991, a diverse selection of Best Management Practices (BMPs) such as Integrated Crop Management (ICM), installation of terraces and water and sediment control basins, and stripcropping have been successfully applied by the majority of landowners within the watershed (Table 1). Iowa State University Extension (ISUE) reports that pesticide and nutrient loading has been reduced on 45% of the cropland acres through the delivery of an ICM assistance program. The Natural Resources Conservation Service (NRCS) estimates that sediment delivery to the stream has been reduced by over 40%. These achievements are significant, yet many acres were untreated.


Table 1: BMPs Applied 1991-1997




Conservation Cropping (Rotations)



Conservation Tillage



Contour Farming



Grade Stabilization Structures



Integrated Crop Mgmt.



Nutrient & Pest Mgmt.



Pasture and Hayland Management



Streambank Protection






Timber Management Plans



Water & Sediment Control Basins




In the mid-1990’s, the local project coordinators attempted to identify the barriers preventing additional landowners from adopting the selected BMPs. Through one-on-one inquiries, group meetings, and questionnaires, it became apparent that most of these barriers centered on economic concerns. Many landowners noted the environmental benefits of the selected BMPs, but were reluctant to adopt them due to the direct costs involved.

The agencies worked to develop alternative cost-effective BMPs which would overcome many of the identified barriers, while meeting the overall project objectives of reducing sediment, nutrient, and pesticide delivery to the stream. Primary efforts were focused on the areas of streambank stabilization and nutrient and pest management.

Development of ISUE’s Nutrient and Pest Management Incentive Education Program

It is recognized that improving the environmental sustainablility of agriculture will require producers to increase the intensity of their management. For crop nutrient and pest management, there are well established refinements which publicly supported projects in Iowa have documented to reduce excess loading of agricultural chemicals, increase the use of on-farm resources, and maintain or increase profitability.

Existing financial incentives for nutrient and pest management often depend on expert assistance provided to cooperating producers, and lack an educational component. Producers receiving incentives hire crop consultants to "deliver" plans, scouting reports, and recommendations. At the beginning of the Sny Magill project, an integrated crop management (ICM) program was offered. Involved producers enrolled over 300 acres, and reduced nitrogen applications by nearly 40,000 pounds during the 1994 crop year. While successful from a reduction standpoint, in-progress project surveys showed little evidence that this program changed producer’s long-term attitudes about more sustainable management.

The Nutrient and Pest Management Incentive Education Program (NPMI) is a local initiative developed by staff of the Sny Magill Creek Hydrologic Unit Area (HUA) and Northeast Iowa Demonstration projects. To enhance long-term adoption of practices, it requires participating farmers to learn the basics of managing their own nutrient and pest management programs. The program is targeted to an area where private consultants are either not available or are unwilling to serve small crop acreage farms, including many livestock operations. By moving through the program in a series of workshops with a group of 8 to 10 participants, the program also establishes a peer support mechanism (Figure 2).


  Figure 2. NPMI workshops allow producers to learn from each other.


Workshop sessions involve reading soil maps and soil test reports, fertilizing for realistic yield goals, as well as determining manure inventories and legume and manure fertility credits. The program allows cooperators to develop, write, and implement their own nutrient, manure utilization, and pest management plans (Figure 3).


  Figure 3. The NPMI program allows cooperators to develop and implement their own nutrient, manure utilization, and pest management plans.


Producers receive incentive payments of $1/acre up to a $250 maximum payment for: 1) all crop acres in the management program; 2) all acres covered by their manure distribution plan; and 3) all acres covered by end-of-year field records, according to a record system set up by the project. Additional payments are made at the end of the second and third years for records and for completing an annual survey of nutrient and pest management practices. Pest management planning and basics of field scouting are also introduced. In all, each participant may earn up to $750 in the first year, and $250 in each of years two and three of the program. The maximum payment levels were set high enough to compensate for time spent completing program requirements and to provide some incentive, such as partially offsetting required soil test costs, but low enough not to compete with private crop consultants’ fees.

Project staff are available to consult with participants. A biweekly newsletter with useful scouting, field, and pest management information is distributed to participants during the cropping season. Ten to twelve issues are normally provided to participants. The end-of-year workshop includes an economic evaluation of changes made. This approach is meant to give producers the knowledge and confidence to control their own nutrient and pest management programs, whether they choose to do it themselves or to work with suppliers or consultants in the future.

This program pays incentives for performance of specific program components. A flexible payment source is a critical component of this program, as timing and amounts of payments vary from one producer to another. Traditional agency programs have been set up to provide one payment per year to producers.

Since 1994, sixty-six producers in three northeast Iowa water quality project areas have participated in this program. Ten Sny Magill area producers have been enrolled. Because of the relatively small numbers of participants in this pilot program, evaluation data (baseline and annual post-workshop surveys) have been aggregated for all three water quality projects. The three projects represent different watersheds in the same topography, with a similar mix of producers, farm resources, and environmental concerns.

Comparison of baseline and annual surveys of program participants showed increased confidence in their own ability to manage fertility programs (rather than relying on suppliers), reduced use of purchased fertilizers, and improved manure management. Survey responses from 25 producers completing the first year of the NPMI program are as follows:

  • 75 percent indicated they reduced nitrogen use.
  • 76 percent indicated it was profitable to reduce N use. The improved net income ranged up to $5,500 per farm.
  • 67 percent changed manure management. Fifty-six percent of those changing manure management did so by spreading fields that could benefit most from manure. Others noted that they spread manure more uniformly to gain more nutrient credit, or spread more acres when they realized that they were overapplying nutrients.
  • 70 percent of the NPMI producers plan to change their insect or weed management programs. Reasons for adjustments include seeking improved weed control with improved timing of spray application, self spraying to avoid custom applicator skips, and seeking increased flexibility with products to match weed problems.

Responses to open-ended survey questions indicate these practices are profitable:

  • "Taking credit for the manure application saved $1000 in fertilizer."
  • "Continuing to back down nitrogen rates on sod to corn saved $480 on my farm."
  • "Changing the rate of manure per acre after calculating crop needs and credits increased the profit on this farm by $1,400 to $2,000."

The Nutrient and Pest Management Incentive Education program is being evaluated on its effectiveness to: 1) improve or maintain water quality by refining the use of pesticides and fertilizers, including manure and legume credits; 2) reach the low acreage, diversified young farmers that have the greatest potential to effectively use on-farm nutrients, thus reduce off-farm fertilizer purchases and as a result, improve farm profit; and 3) provide a cost effective incentive program that can be efficiently delivered and evaluated for performance. The goal is to insure that publicly funded management incentives result in sustainable crop management practices that participants will maintain throughout their farming careers.

This program currently represents the primary focus of alternative nutrient and pest management efforts. In order to further reduce sediment load, additional emphasis was placed on innovative streambank stabilization demonstrations.

Alternative Streambank Stabilization Initiative

The project offers landowners many alternative BMPs for reduction of sedimentation resulting from rill, sheet, and gully erosion. For example, if landowners cannot afford tile outlet terraces, other equally effective sediment reducing BMPs such as contour stripcropping could be offered. When working with streambank erosion problems, however, our available BMP list was limited to effective, albeit expensive, rock rip-rap based technologies. This problem is not isolated to this project. Several projects across the country are faced with this situation. Often landowners with farms along streams simply cannot justify spending their limited income, even with cost share, to benefit and protect such a small area.

Unfortunately, recent studies in Illinois indicate that as much as 60% of the sediment found in small-to-mid size Midwestern streams is derived through streambank erosion. Even though opinions differ on how to resolve streambank erosion problems, few fail to recognize its significance. Everyone involved with the Sny Magill Watershed Project realized that to make significant sediment reductions, the issue of streambank stabilization would have to be addressed. The use of traditional rock rip-rap based technologies was not the answer since so few landowners could afford their use. A more cost effective approach needed to be found.

In 1994, local project coordinators began exploring the use of soil bioengineering. The basis of this technology is the use of plant materials in conjunction with limited structural materials. Together, they provide a sound streambank stabilization installation, but utilize less expensive materials.

Working with an NRCS specialist, the local project coordinators invited several federal, state, and county agencies to work together, and have subsequently applied a series of installations to learn more about the uses and limitations of this technology. In the spring of 1995, the first installations using willow posts, fascines, and brush mattresses were installed. More were installed using slightly different combinations in the fall. These installations were completed on a six- foot high bank and cost approximately $12 per lineal foot, or 1/3 the cost of traditional rock rip-rap based methods (for a bank of this height), and have been inundated by floods at least four times with no apparent damage to the streambank (Figures 4 and 5).


  Figure 4. A "before" photograph of the streambank stabilization installation site (spring 1995).
  Figure 5. An "after" photograph of the streambank stabilization installation (late summer 1997). Native willow posts were used.


In the summer of 1996, warm season prairie grasses were planted (Figure 6). Both willows and warm season grasses possess deep penetrating root systems, which hold loose soil in place. Warm season grasses are an alternative for landowners that fear encroachment of willows into cropland. A major problem with warm season grasses, however, is their slow initial growth. Several species take two full growing seasons to become established. Therefore, in this installation, bio-degradable mulch mats were utilized. The mats should hold the loose soil for two to three years, allowing the warm season grasses the time they need to grow and form a dense sod layer. The cost of this installation on a five- foot high bank was $8 per lineal foot, or 1/7 that of traditional rock rip-rap methods (for a bank of this height).


  Figure 6. Warm season grasses were used for one streambank stabilization project.


The use of soil bioengineering technologies does have its limitations. Since the primary stabilizing measures are living, special care must be taken to ensure their survival. Willows and grasses must be frequently scouted for insect, beaver, and ice damage. Failure to conduct periodic inspections and perform required maintenance could lead to failure of the entire installation.

One of the primary instability problems associated with the streambanks is the traffic patterns created by heavy fishing pressure. One of the willow installations failed to survive because anglers simply trampled it. For this reason the use of vegetation was abandoned when the most heavily fished stretch of the stream was stabilized. While surveying, it was noticed that a significant number of anglers using this stretch of the stream had limited mobility. As a result, accessibility for physically challenged individuals was incorporated into the project design (Figure 7). Traditional installations would have included concrete and asphalt, which were not used due to high cost and maintenance considerations. Items such as rock gabion baskets and crushed limestone were used which will allow proper access, have few maintenance concerns, and remain cost effective.


  Figure 7. One streambank stabilization site on Sny Magill Creek incorporated designs to be accessible to physically challenged individuals.


Plans were made to install a series of low stone weirs across the stream in 1998. The weirs will be used to help reestablish a stable pool and riffle sequence, which will not only help stabilize the channel grade and streambanks, but will significantly increase the in-stream habitat potential of the stream.

Lessons Learned

The Nutrient and Pest Management Incentive Education Program and the Alternative Streambank Stabilization Initiative represent innovative local efforts to improve water quality.

Providing expert assistance to write crop management plans and recommendations for the producer does not ensure that they will continue practices on their own. By including an educational component, the NPMI program allows cooperators to develop, write, and implement their own nutrient, manure utilization, and pest management plans. This provides for long-term adoption of practices.

The Alternative Streambank Stabilization Initiative is an effort to develop and demonstrate new, lower cost streambank stabilization technology. The evaluation of these demonstrations is just beginning, as the installations have been in place less than two years. Efforts focus on installations that can be completed with minimum cost and equipment requirements. The sediment load to Sny Magill Creek is directly impacted by these efforts, while indirect results occur from the technical guidance that is applied to watersheds in other areas.

Modified from Proceedings of the National Watershed Water Quality Project Symposium, 1997, Cosponsored by the U.S. Department of Agriculture and the U.S. Environmental Protection Agency, in cooperation with the Conservation Technology Information Center: U.S. Environmental Protection Agency, EPA/625/R-97/008, p. 85-89.