Final Report for LNC00-167

Southeast Iowa Agroforestry Demonstration

Project Type: Research and Education
Funds awarded in 2000: $9,650.00
Projected End Date: 12/31/2004
Matching Federal Funds: $1,000.00
Matching Non-Federal Funds: $3,500.00
Region: North Central
State: Iowa
Project Coordinator:
Christa Perkins
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Project Information


The initial focus of this demonstration was to show the economic benefits of establishing for harvest several monoculture beds containing local ecotype forbs and medicinals between existing rows of trees. While the system itself shows promise, a number of problems were encountered in this project relating to the intense management required to demonstrate the original project objectives. The initial project designers had assumed a greater interest by the partners and under-estimated coordination time required by the sponsor.

Despite issues related to management, this project has lead to an increased interest in a potentially valuable management system using warm season and cool season grasses. The resulting system of double cropping both warm and cool season species in the same field has anecdotal benefits that will be analyzed in a follow up project with Iowa State University. Long-term management of demonstration fields established in Southern Iowa at the Des Moines County Landfill can provide further information on system viability.

The positive outcome noted above is the design and likely implementation of a more detailed research and demonstration effort to be carried out by Iowa Native Lands, Inc., Iowa State University and the Leopold Center for Sustainable Agriculture. Sponsors of this project will continue to monitor progress for the benefit of Southeastern Iowa landowners and would encourage others interested in Agroforestry, double cropping and productive use of marginal land to do the same.


One of the primary goals of the USDA Conservation Reserve Program (CRP) is to idle marginal, highly erodible cropland. Further, current eligibility criteria clearly shows how the USDA is encouraging landowners to plant trees on their enrolled acres. One of the main drawbacks, from the landowner’s point of view, is the lack of economic return on their investment between the end of the CRP contract and until the trees reach economic maturity.

Our original agroforestry demonstration (1993-1999) was conducted to make agroforestry practices more acceptable to landowners, however, the format chosen has been completed. Our current plans are to enhance the original concept and seed high value, local eco-type forbs and medicinal amongst our existing trees. This again, is an attempt to convince landowners of the importance and economic viability of such soil conservation practices.

Project Objectives:
  • Show landowners the environmental benefits of agroforestry

    Encourage them to convert marginal cropland to more environmentally beneficial land uses.

    Demonstrate to private entrepreneurs the economic potential of growing, harvesting, and selling multiple crops to maximize the use of local ecotype forbs and medicinal.

    Help local leaders preserve through propagation irreplaceable local ecotype forbs and medicinals.


Click linked name(s) to expand
  • Jeff Bergman
  • Tom Buckley
  • Jeff Chase
  • Joe Haffner
  • Hal Morton


Materials and methods:

Dry Upland Savannah
Narrow seedbeds of local eco-type forbs and medicinals were planted between the existing rows of trees at the Des Moines County Landfill. The tree planting itself was a demonstration of direct seeding when the original agroforestry demonstration was established in the fall of 1993. The trees are in rows 9’ to 20’ apart, planted both in north-south and east-west rows. The seedbeds were planted 4-6’ wide, 50-75’ long taking into account direction of the trees and shade tolerance of the species. Management of the site included herbicide treatment and mowing. Burning of the site was not permitted due to the location of the plot at the landfill and presence of methane gas danger.

The original demonstration premise was designed to show the potential of using native plants with a potentially high value market value (such as ecotype seed and medicinals) in an alley cropping or agroforestry setting. Early attempts to establish forbs proved difficult and lead to more of a focus on natives in general as a supplemental income crop for southern Iowa lands. Hence the committee decided that modifications were needed to existing and planned seeding at the landfill site. The seeding was heavily infested with weeds and rescue mowing was less than successful.

The local project committee decided to add another facet to the project by developing a plan to expand the diversity, viability and income potential through a more compatible native plant-based cropping system to enhance agro-forestry management. Discussions with various Southern Iowa producers indicated that a warm season-cool season seeding and management system had proven successful in marginal cropping situations. Integration of this approach was thought to provide better establishment conditions, improve weed control, increase the diversity to support forbs establishment and provide an alternative income opportunity.

Plans were made to move forward with double-cropping a cool-season legume (alfalfa) and a warm-season forage grass (big bluestem). This seeding which was to be completed between established rows of trees at the Des Moines County Landfill, and be consistent with project objectives, would demonstrate additional benefits of Agroforestry. In response to weed infestations and the need for better establishment conditions for native prairie vegetation specific to the site conditions of the landfill, a 3-acre modification to the demonstration was proposed and subsequently implemented.

Plans called for the two species to be seeded together, and the crops managed to facilitate optimum production. The alfalfa would be harvested for hay in late spring, and the big bluestem would be allowed to grow. In mid summer the big bluestem would be harvested for hay and used as winter-feed for stock cows. Secondary benefits anticipated were an increase in weed control due to seasonal growth patterns and harvest incentives. The potential to add forbs during and after grass establishment would take advantage of the warm season – cool season system as a medium for the production of higher value natives originally proposed for use on site.

Because both alfalfa and big bluestem are slow to produce a crop (usually the second year), the results would not be fully recognized until at least the second growing season. Growth was to be monitored for the two forages.

Proposed Timeline for Plan Modifications:

• Prepare Site – April 2003
• Drill big bluestem and alfalfa – April 2003
• Mow weeds – June 2003
• Harvest alfalfa – early Sept. 2003
• Harvest alfalfa – May 2004
• Harvest big bluestem – July 2004

Seed and Fertilizer Requirements:

• 50 pounds alfalfa seed
• 50 pounds big bluestem
• Additional Forbs as recommended
• Maintenance Level Application of P & K

Wetland Lowland Savannah
The primary site for this planting was to be located at the Des Moines County Landfill, but due to a heavy infestation of Reeds Canary Grass the committee decided to move the plot to the Iowa Army Ammunition Plant (IAAP). The planting was completed in June. Due to the events of 9/11 access to this sight is very limited. An evaluation of optional sites was completed and land owned by the Des Moines County Conservation Board was selected. This sight was prepared with a treatment of plateau in May of 2002. However, this planting failed. The failure is contributed to the lack of time between the herbicide application and planting.
The wetland site located on the Des Moines County Conservation Board property is being monitored. Due to river maintenance activities restricting flow of water in the area, the viability of the planting is in question. It is anticipated that if this planting fails an additional planting will not occur.

Research conclusions:

The local impacts of this project are likely to be very small. The combined problems associated with project design for contributed labor, the site selection, adverse conditions and the absence and turn over of project coordinators, have limited the success of this project.

However, the subsequent introduction of warm season double cropping as a possible companion to tree crops has spurred the interest of another organization for the purpose of advancing the use of native species. Iowa Native Lands were brought into this project to design, implement and promote the double cropping option. A direct result is the development of a follow up project by Iowa Native Lands, Iowa State University and the Leopold Center for Sustainable Agriculture. The results of this project will be shared with the sponsors of this effort. A project outline of the follow up research is provided below.

One final conclusion and caution for similar projects in the future, original project resource needed to carry out this project were underestimated. This effort was carried out over a 5-year period on approximately 6 acres in two locations with a total budget of around $9,000 with local in-kind contributions.

Estimates obtained from outside contractors in Year 3 to design and implement the double cropping component alone were over $10,000 (Iowa Native Lands was willing to complete for a much lower cost because of its interest in the system and native plant related objectives). As a comparison the follow-on project mentioned above is estimated to require over $15,000 to complete 2 years work on 3 acres at ISU research farms.

Participation Summary

Educational & Outreach Activities

Participation Summary

Education/outreach description:

The attached project brochure was distributed to local USDA Service Centers, County Conservation Boards and other project partners. Due to the issues related to this project sound economic data is not available to promote this as an economically viable option. It is anticipated that double cropping forage system will prove successful and the data from this plot, combined with data from future investigators, can be promoted to landowners at a later date.

Project Outcomes


Areas needing additional study

Investigating a Double Crop Forage Production System that Includes Native Plants

Early Iowa settlers routinely used native prairies as a forage source for their farm animals. Many prairie species are considered high quality forage during the growing season (1, 2). However, in recent years most Iowa grazing and forage production operations have used low-diversity fields of non-native grasses. Profit from such systems is sometimes marginal, and compromised by the need for routine fertilizer applications and re-seeding. Further problems are caused by the predominantly cool season grasses typically planted in these pastures – during hot weather productivity is dramatically reduced.

Several years ago a double cropping forage system was inadvertently established on a farm in southern Iowa. A producer decided to plant a field of native warm season (prairie) grasses into an alfalfa field that appeared to be in decline. Native grasses were planted in the fall after disking the field. Instead, the planting and disking disturbance rejuvenated the alfalfa, which then grew vigorously the following spring. The producer proceeded to harvest the alfalfa for forage in late spring, with the expectation that the grass seeding was a failure due to competition from the alfalfa. However, the warm season grasses produced a healthy stand, allowing a second forage harvest.

We believe the alfalfa had produced a “crop” of nitrogen-fixing root nodules, which decomposed after the alfalfa was mowed. This produced a below-ground flush of nitrogen at the same time the soil began to warm significantly (due to increased sun exposure after the alfalfa cover was removed); both conditions served to encourage growth of the warm season grasses. Alfalfa would usually be expected to provide too much competition for the native grasses to thrive, but timely haying instead reduced competition and inadvertently produced conditions that encourage native grass development. This “system” has the potential to cycle in this manner repeatedly, with a continuous input of nitrogen from the alfalfa nodules.

The example described above was fortuitous; the potential utility of such a system for forage production suggests it is worth duplicating under controlled circumstances. Although the use of combinations of cool/warm season plants in pastures has been previously suggested; this system we are proposing appears unique in its emphasis on the legume component (both cool and warm season), and in its emphasis on higher diversity warm season native species plantings. Studies on the forage potential of mixed prairie plantings have been done in other states with drier climates than Iowa (1,2). Some preliminary work with non-native legumes planted with native grasses has been done in Iowa: George et al. (4) planted a variety of cool season legumes into switchgrass cultivar monocultures, and concluded there was potential for forage production, and reduced N application. Moore et al. (5) planted cool season legumes into switchgrass and big blue stem monocultures in the Loess Hills and found that the grasses tended to die out and the legumes take over. Their results may have been complicated by a drought during the experimental period, competition from bromegrass present before the experimental plots were established, their location, and the experimental design using grazing rather than mowing.

We propose a set of forage production trials using cool season legumes planted in combination with warm season native perennial species. We anticipate demonstrating a viable technique for low-input but high output forage production, using primarily native prairie species. It is anticipated that this will lead to the development of a stable perennial plant forage production system which can be harvested up to twice a year with minimal fertilizer application. Assuming positive results, the next step of this project is to promote similar trials on a larger scale, and to direct efforts to improve existing low diversity pastures. Our goal is a process for a low chemical input technique for high quality forage production, primarily using native perennial plants.

It is hoped that landowners currently row-cropping marginal agricultural land, and producers with traditional pasture vegetation will see this system as a financially attractive alternative to current practices. It is anticipated that this system would be particularly attractive to landowners in southern Iowa, where soils are less productive and more susceptible to erosion than those in more northern areas of the state. There are also more grazing operations in southern Iowa than in the north, so the market for forage is more significant.

An important and timely aspect of the proposal is to develop options for Conservation Reserve Program (CRP) land coming out of contract. Currently there are about 1.8 million acres of CRP in Iowa (3). Beginning in 2007 hundreds of thousands of those acres will begin coming out of contract, and there is significant concern that new contracts will not be offered to many or most landowners. If an economically viable alternative to row-cropping, such as that proposed here, can be demonstrated to those landowners, it may prevent the removal of the established perennial system on those acres –which by definition are on erodible land.

Additionally, numerous environmental benefits will result from greater acreage planted to deep rooted native prairie species by producers adopting this system. The current common practice uses low species diversity stands of non-native grasses that require regular soil disturbance and routine fertilizer inputs. In the proposed system we expect yield stability through increased species diversity, general habitat improvement, improved soil stabilization and quality, better storm water infiltration, and the potential for fall hunting opportunities in the native habit.

Project General Description

Sites: We will work with Iowa State University research personnel at Armstrong Research and Demonstration Farm in Lewis, and a farm in the Ames area privately owned and operated by Bob Gelina. Replication of the experiment at these two sites will allow us to set this forage production system up in two ways: putting prairie seed into an old alfalfa field (Ames Gelina farm), and establishment from bare soil (Lewis farm).

General Design: The basic production system will be a cool season legume crop mixed with warm season native prairie species, harvested up to twice per year on dates chosen for optimal forage quality. Two cool season legumes will be evaluated (alfalfa and medium red clover) at the Lewis farm, only alfalfa at the Gelina farm. Two native seed mixes, low and high diversity (appendix), will be planted. At the Lewis farm prairie mixtures will be planted first and allowed to establish before legumes are interseeded. Prairie mixtures will be seeded directly into the alfalfa stand at the Ames Gelina farm.

This research is designed to evaluate establishment of the 2-forage system, with preliminary analyses of the harvested products.

Species selection: The warm season prairie species were selected for biomass production and grazing preferences (appendix 1). Many prairie species are “decreasers”; these species tend to die out of prairie pastures due to preferential grazing. We also included any warm season legumes available, for added nitrogen fixation potential. Alfalfa and medium red clover were chosen because they are commonly used cool season legumes.

Lewis farm: The legume interseeding will be done at two time points: one, and two growing seasons after planting the warm season mixtures. Collecting data from plots that were allowed a second prairie establishment year before legume interseeding is important due to the slow rates of development of many prairie species. If the warm season species are not well established before interseeding there is a risk of the cool season species overwhelming the system, causing the warm season plantings to die out.

Ames Gelina farm: Prairie seed mixes will be broadcast seeded into the alfalfa after disking the field. Both disking and seeding will be done fall 2004.

Analysis: Forage production will be evaluated between the experimental plots. Forage from two replicates will be combined for nutrient analysis. Standard tests for quality will be used (dry matter, wet chemistry analysis). Informal animal acceptance trials will be performed on feed lot cattle. Data will be collected on species diversity/establishment for the prairie mixtures during the study.

Expected outcomes: By demonstrating the utility and viability of this system under controlled conditions, and addressing some of the potential concerns about establishment, we expect to produce sufficient data to encourage larger research and production trials.

Note: The original observation we are attempting to re-create for evaluation purposes was the result of warm season grasses being seeded into an existing alfalfa field. The long term potential of this system may indeed be establishment of warm season forages into existing vegetation, and one phase of the current project (Ames Gelina farm) will be an attempt to replicate that observation. The second study site, at the Lewis farm, will replicate the experiment starting from bare soil. This will reduce variations produced by the presence of pre-existing vegetation and provide important contrast.





4. George, J.R., Blanchet, K.M., Gettle, R.M., Buxton, D.R., and Moore, K.J. 1995 Yield and Botanical Composition of Legumes Interseeded vs. Nitrogen Fertilized Switchgrass. Agron. J. 87:1147-1153

5. Moore, K. Leopold Center Progress Report, V13 (2004) pg 21-24

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.