Native Perennial Legumes: New Species for Grazing Systems

Final Report for LNC99-155

Project Type: Research and Education
Funds awarded in 1999: $100,000.00
Projected End Date: 12/31/2002
Matching Non-Federal Funds: $125,406.00
Region: North Central
State: Minnesota
Project Coordinator:
Nancy Ehlke
University of Minnesota
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Project Information


Native perennial legumes were once a vital component of Midwestern grassland ecosystems. We have evaluated the establishment of two native legumes, Illinois bundleflower and false indigo, in grazing systems on four farms in western and southeastern Minnesota. We have laid the foundation for plant breeding programs for both species using germplasm collected from the north central United States. We have seed of three source-identified populations of Illinois bundleflower and collected seed from our breeding nurseries in Fall, 2002, to initiate our plant breeding program.


Indigenous legumes were important components of the diverse Minnesota grassland and prairie ecosystems and present a unique opportunity to increase the diversity and profitability of modern agricultural systems. Although a number of the perennial indigenous legumes have potential as alternative grain and biomass fuel crops, the most expedient use of indigenous legumes will be as new forage species utilized in grazing systems.

Illinois bundleflower (Desmanthus illinoensis) is a prairie legume with a native range extending north to Minnesota and North Dakota, southwest to New Mexico, and southeast to Florida. The Land Institute of Salina, Kansas, has conducted research with this plant and considers it to have great potential as a perennial grain crop for human consumption. Illinois bundleflower does not begin to grow until early June, and is most productive during the month of July. The species will produce a deep taproot, flower, and set seed in the first year (Hellwinckel 1992). The plant is often most productive in lowland sites with moist soils, but does also occur on dry upland locations (Towne and Knapp 1996). It has been tested by the United States Department of Agriculture (USDA), and no toxic levels of oxalates, cyanides, nitrates, or alkaloids have been found in the seed or foliage (Kulakow et al. 1990). It has the ability to fix atmospheric nitrogen at rates similar to alfalfa or soybean (Kulakow et al. 1990). Seed yields in the central United States have been as high as 1513 lb/acre, with average yields of 1068 lb/acre; shattering is common, but plants with resistance to shattering have been discovered (Kulakow et al. 1990). Due to this heavy seed production, Illinois bundleflower will naturally reseed in a pasture (Dovel et al. 1990).

Illinois bundleflower establishment has been investigated. The first important step for successful establishment is seed scarification which increased germination from near zero to ninety percent (Carre and Cavigelli 1985). Dovel et al. (1990) studied the establishment of Illinois bundleflower in a Texas warm-season grass pasture, and its impact on rangeland production and quality. They found disking followed by broadcast seeding at 6 lb/acre to be an effective establishment method. Interseeding with Illinois bundleflower increased forage yield by 45 percent over unimproved pasture, and after four years the stand was still persistent, with Illinois bundleflower yielding over 2500 lbs/acre dry matter. Posler et al. (1993) also studied the potential for Illinois bundleflower as a forage species for mixture with warm season grasses in Kansas. They found that the plant drastically increased total forage yield, but slightly reduced in vitro dry matter digestibility as compared to grass alone. Most importantly, Illinois bundleflower in mixture with grass more than doubled the crude protein concentration in the mixture versus grass monoculture.

False indigo (Amorpha fruticosa) has been the investigated for its potential as a forage (Papachristou and Papanastasis 1994), and biomass energy crop (Roth, et al. 1984). This plant is a true shrub, producing woody stems that do not die back in winter. It is native to most of the continental United States, commonly occurring along rivers, streams, and lakes, but also in desert areas and on dry rocky outcroppings. We have observed it thriving in standing water and on extremely rocky prairie preserves in southwest Minnesota. False indigo is a warm-season legume.Its buds do not break dormancy in Minnesota until mid-May, but it grows rapidly during July and August (Lueschen 1997). It can grow about three feet in height per season, and at maturity has a square appearance with height and width of about ten feet. It forms a deep tap root system that is heavily nodulated by nitrogen-fixing bacteria (Allen and Allen 1981). False indigo has not been utilized in North America as a forage, but it has been used in Mediterranean countries.

Studies at the St. Paul research station have demonstrated the potential for rapid establishment of false indigo, with monocultured yields exceeding three tons of dry matter per acre in the second season (Lueschen 1996). Third year yield from plants that were harvested the preceding fall have exceeded seven tons of dry matter per acre, and contained 13.3 percent crude protein (Lueschen 1997). Plants harvested in the spring of the third year had crude protein concentrations over 20 percent (Lueschen 1997).

Grazing systems: The profitability and expansion of grazing systems is currently limited by several factors that may be overcome with the reintroduction of indigenous legumes. First, the productivity of our predominate, cool-season grass pastures in Minnesota is uneven with about two-thirds of the forage biomass being produced in the first one-third of the growing season. Several of the indigenous legumes including Illinois bundleflower (Desmanthis illlinoensis) and false indigo (Amorpha fruticosa) grow rapidly during the summer months and maintain high forage quality during the growing season when it is most needed by producers. Second, legumes have the ability to fix nitrogen which increases forage yield and quality of the pasture. The most commonly utilized legumes are often slow to establish and lack persistence. Illinois bundleflower and false indigo can establish rapidly, are productive in the seedling year, and are persistent. Third, farmers with low-lying or floodplain pastures cannot use current forage legumes because of high soil moisture and shade from vegetation. The legumes we are studying are found naturally in these types of environments and should be highly productive. The introduction of native legumes into these pastures should improve the profitability of the pastures and expand the use of controlled grazing along rivers resulting on a reduction in nonpoint source surface water contamination. Fourth, non-native legumes are incompatible with native warm-season grasses. Native legumes should be able to coexist and enhance warm-season grass pastures since they occur naturally in prairie ecosystems where warm-season grasses predominate. With eight million acres of warm-season grasses previously established through the Conservation Reserve program, the addition of native legumes into these grasslands will enhance the yield, quality and profitability of grazing and thus reduce the conversion back to cropland.

Allen, O.N., and E.K. Allen. 1981. The Leguminosae. Madison: University of Wisconsin. 42-43.

Carre, D., and M. Cavigelli. 1985. Effects of Density on Yield of Illinois Bundleflower (Desmanthus illinoinsis) and Wild Senna (Senna marilandica). The Land Report Research Supplement 2:7-9.

Dovel, R.L., M.A. Hussey, and E.C. Holt. 1990. Establishment and survival of Illinois bundleflower inter-seeded into an established kleingrass pasture. Journal of Range Management 43:153-156.

Hellwinckel, C. 1992. Comparison between stable and high seed yielding collections of Illinois
bundleflower (Desmanthus illinoensis). The Land Institute Research Report 12:20-25.

Kulakow, P.A., L.L. Benson, and J.G. Vail. 1990. Prospects for Domesticating Illinois Bundleflower. in J. Janik and J.E. Simon (ed.) Advances in New Crops. Portland: Timber Press. 168-171.

Lueschen, W.E. 1996. Unpublished data collected in 1996 from the native perennial legume nursery on the University of Minnesota Saint Paul Experiment Station. The nursery was established in 1995.

Lueschen, W.E. 1997. Unpublished data collected in 1997 from the native perennial legume nursery on the University of Minnesota Saint Paul Experiment Station. The nursery was established in 1995.

Papachristou, T.G., and V.P. Papanastasis. 1994. Forage value of Mediterranean deciduous woody fodder species and its implication to management of silvo-pastoral systems for goats. Agroforestry Systems 27:269-282.

Posler, G.L., A.W. Lessen, and G.L. Fine. 1993. Forage yield, quality, compatibility, and persistence of warm-season grass-legume mixtures. Agronomy Journal 85:554-560.

Roth, et al. 1984. Evaluation of 107 Legumes for Renewable Sources of Energy. Economic Botany 38:358-364.

Towne, E.G., and A.K. Knapp. 1996. Biomass and density responses in tallgrass prairie legumes
to annual fire and topographic position. American Journal of Botany 83:175-179.

Project Objectives:

Objective 1: To evaluate establishment and persistence of two native perennial legumes in grazing systems using a research and education network.

Objective 2: To initiate two native perennial legume breeding programs.


Materials and methods:

Objective 1: To evaluate establishment and persistence of two native perennial legumes in grazing systems using a research and education network.

Establishment trials were initiated at Montevideo, Minnesota, and Milan, Minnesota in 1999. On-farm plot areas were identified and tested for soil fertility. Frost seeded plots were established in November, 1999, and spring seeded plots were established in April, 2000. The experimental design was a randomized complete block with three replicates and a minimum plot size of ten feet by 30 feet. Species seeded were Illinois bundleflower, false indigo, alfalfa and a control (no seeding). Stand counts were taken in June, 2000, 2001, and 2002 at both on-farm sites.

Establishment trials were initiated at Lake City, Minnesota, and Wilson, Minnesota, only in spring of 2000. On-farm plot areas were identified and tested for soil fertility. Spring seeded plots were established in May or June, 2000. The experimental design was a randomized complete block with three replicates and a minimum plot size of ten feet by 30 feet. Species seeded were Illinois bundleflower, false indigo, and a control (no seeding). Stand counts were taken in September, 2000, and June, 2001.

Objective 2: To initiate two native perennial legume breeding programs.

Breeding programs for Illinois bundleflower and False indigo was initiated by establishing 20 populations from the north central United States of each species at Becker, Minnesota, and St. Paul, Minnesota, and at Sioux Center, Iowa, on experiment stations in space-planted nurseries. The nurseries were a randomized complete block design with three, seven or ten replicates with six plants per plot for a total of 2,640 plants per collection. The data collected over two or three years included maturity ratings (vegetative, flowering, and seed set), forage yield and quality, seed data (yield, weight, percent protein), stem data (length, number, plant height, plant width, lodging), reproductive data (seeds per inflorescence, pods per inflorescence, pod length, pod width, peduncle length), and leaf data (area of five leaves, length, width).

Research results and discussion:

At both sites, the establishment of false indigo and Illinois bundleflower was more successful with spring seedings than with frost seedings in the fall. Stand counts for the fall frost seeding showed no established plants of either species in June, 2000. The spring seeded plots showed that Illinois bundleflower established better than false indigo averaging four plants per square foot verses one plant per square foot for false indigo. However, the extremely dry conditions during fall of 2000 resulted in the complete loss of both legumes on the Handeen Farm and the loss of Illinois bundleflower on the Struxness Farm. Stand counts of false indigo were reduced to one plant per square meter on the Struxness Farm. Stands were too poor to take dry matter yields of grasses, legumes and weeds and to determine the forage quality of the pasture. Final stand counts were taken in June, 2002, and no plants were found at either farm site.

In September, 2000, the spring establishment trials in southeastern Minnesota initially showed better success with both species. Illinois bundleflower has greater plant counts than false indigo at all on-farm sites but did not establish when competition from other companion species was not controlled (Lake City location). In June, 2001, plant stand counts were reduced but were adequate at the Dansburger Farm. At the Lentz Farm, Illinois bundleflower and false indigo were completely lost in the unclipped treatment and were greatly reduced in the clipped treatment. Competition must be controlled in established pastures to have successful introduction of these legumes into pastures. Stands were to poor to take dry matter yields of grasses, legumes and weeds and to determine the forage quality of the pasture. Visual observations of the Dansburger farm in 2002 indicated some survival of the two legume species in the pastures.

Basic genetic and agronomic information about false indigo and Illinois bundleflower for use in developing successful plant breeding strategies and agronomic research priorities was collected during 1999 and 2000. Analysis of the Illinois bundleflower data and False Indigo data is completed.

Three plant breeding populations (source identified) of Illinois bundleflower were identified and seed was increased in 2001 for potential variety release of this native legume for grazing and restoration. A selection program will be initiated for Illinois bundleflower to improve its agronomic performance beginning in 2003.

False indigo collections with excellent potential agronomic and forage quality traits have been identified from the 20 accessions evaluated for potential use in a future plant improvement program. Currently, the 20 accessions are being evaluated as a woody ornamental crop for native landscapes, living snow fences, and restored sites.

Research conclusions:
  • The research conducted on-farm will lead to the development of more successful establishment techniques for Illinois bundleflower and false indigo.

    Grower input will be critical to determine the best management practices for a wide range of grazing systems in Minnesota. However, the incorporation of legumes into pasture systems should increase the profitability of pasture-based livestock systems.

    Environmental impacts to pasture-based systems include reduced soil erosion, decreased fertilizer and chemical runoff, and reduced animal stress.

    Native perennial legumes have the added benefit of enhancing the aesthetics of rural landscapes with their showy flowers and foliage.

    Seed of three source-identified populations of Illinois bundleflower was increased in 2001 for potential release to producers.

    Seed was collected from Illinois bundleflower breeding populations in 2002 to initiate a program to improve the agronomic potential of the species.

    False indigo is being evaluated for potential use as a native woody ornamental crop for use in landscapes and restored sites.

Farmer Adoption

Farmer adoption of this technology using native legume species is slow. This is due primarily to a lack of adequate seed stocks in the market at a reasonable price and the lack of knowledge of proper establishment techniques. We have made substantial progress in determining establishment methods and are actively pursuing the release of Illinois bundleflower populations to producers to address these issues. Through field days, formal presentations, extension meetings, and one-on-one farmer discussions, this project has reached more than 100 farmers in west central and southeastern Minnesota.

Participation Summary

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

Referred Publications:

DeHaan, L.R., N.J. Ehlke, C.C. Sheaffer, D.L.Wyse, and G. J. Muehlbauer. 2003. Illinois
bundleflower genetic diversity determined by AFLP analysis Crop Sci. 43:0000-0000 (in press)


DeHaan, L.R. 2001. Analysis of diversity among accession of Amorpha fruitcosa L. and
Desmanthus illinoensis (Michx) MacMillan. Ph.D. thesis, University of Minnesota, St. Paul.,
Department of Agronomy and Plant Genetics.

Byun, Jaehyun. 2002. Dinitrogen fixation in Illinois bundleflower. M.S. thesis, University of
Minnesota, St. Paul., Department of Agronomy and Plant Genetics.


Prairie Plant Field Day was held on September 7, 2000 at Wilson, Minnesota, to discuss establishment techniques for False Indigo and Illinois bundleflower in cooperation with the Land Stewardship Project in Lewiston. Fifteen farmers attended.

Indigenous Legume Growers Winter Meetings was held on March 29, 2001, in Montevideo, Minnesota, to discuss the potential uses, establishment techniques, and potential management strategies on native legumes concentrating on Illinois bundleflower and false indigo in cooperation with Western Minnesota Land Stewardship Project. Twenty producers attended.

DeHann, L.R., N.J. Ehlke, and C.C. Sheaffer. 2000. Analysis of diversity in northern populations of Illinois bundleflower. Agron. Abst. p. 182.

DeHaan, L.R., N.J. Ehlke, E.H. Ristau, C.C.Sheaffer, D.A. Somers, and D.L. Wyse. 2000.
Indigenous legumes for Minnesota Landscapes. Symposium: Enhanced landscape, human and
animal health symposium. p. 33. 28 April 2002, St. Paul, Minnesota.

Web site:

Indigenous native legumes:{1BCE440B-972F-43A6-97

Project Outcomes


Areas needing additional study

Native perennial legumes such as false indigo and Illinois bundleflower have potential as forage and grain crops. Additional research is being conducted on the successful establishment and grazing management systems for these warm season legumes in livestock systems. The potential for grain production of Illinois bundleflower appears to be high, additional studies on grain yield/seed production must be preformed in multiple environments to ensure sufficient levels of seed in the market for producers at a reasonable price.

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.