Farmer-Designed Research on the Use of Legumes in Sustainable Dryland Cropping Systems

Final Report for LNC97-104

Project Type: Research and Education
Funds awarded in 1997: $91,000.00
Projected End Date: 12/31/2002
Matching Federal Funds: $44,500.00
Region: North Central
State: Nebraska
Project Coordinator:
David Baltensperger
University of Nebraska
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Project Information


Use of Austrian winter peas to replace part of the fallow period in the Nebraska Panhandle appears to be of limited economic value unless inorganic nitrogen fertilization is not available (organic operations) or nitrogen becomes significantly higher priced. Wheat yields were reduced slightly following the Austrian winter peas as moisture appeared to be more limiting to the system than nitrogen and total costs were higher when the peas were included. This grant relied heavily on producer involvement as participants have moved on to look at other alternatives including spring planted peas and have helped form a new growers association.


On-farm research, featuring active collaboration of farmers with researchers, is extraordinarily useful in exploring cropping system designs that are applicable in a broad production area. Farmer involvement in the research can also increase credibility of such research within the farming community.

In the wheat-producing region of western Nebraska, the farmer cooperator’s role in research is still very traditional. Farmers typically provide land, labor, machinery, and free access to plots when working with researchers. Involvement in the experimental design or any decision-making aspect of the research is minimal to non-existent.

Research efforts in the North Central Great Plains continue to explore alternative, dryland cropping systems as a solution to problems associated with the traditional wheat-fallow rotation. This project is an opportunity for producers to be directly involved in such an effort, thereby ensuring that the research will be relevant to them and, by extension, to other farmers in the region.

Project Objectives:

Objective 1. Develop an innovative model of farmer collaborator participation in research by actively involving farmers in determining on-farm research objectives and experimental approach.

We propose to develop a contrasting model of farmer involvement, applying the strategy of involving major stakeholders at the very beginning of the planning process and including them as key decision-makers throughout the process. The two primary target audiences are the research community and the farming community. We hope to present both groups with an innovative model for collaboration in research based on the most pressing production questions as determined by farmers, the ultimate users of all agronomic research.

Objective 2. Assess the value of growing a legume green manure crop in the dryland wheat-millet-fallow rotation.

The problem is widespread use of the wheat-fallow rotation in the North Central Great Plains, despite accompanying decreases in soil organic matter and nitrogen content and increases in wind erosion. Diversifying the rotation by growing a legume cover crop shows great promise in ameliorating the drawbacks of fallow. Of the four basic approaches to managing a legume cover crop (seed crop, forage, green manure, or mulch), maximum soil benefits to dryland systems are realized from incorporation of the legume as a green manure. This practice can increase organic matter, add organic nitrogen to the soil, provide a break in insect, weed, and pathogen cycles.

Objective 3. Conduct enterprise budget analyses of the wheat-millet-fallow and wheat-millet legume cropping systems.

In order for innovative production/management practices to be adopted, such practices must be economically viable for the producer. Likewise, a vital component of agronomic research is an accompanying economic analysis so that farmers can find out what recommended practices mean in terms of machinery, labor, fuel, and input costs. We will use partial budget techniques to compare the variable costs and returns for the cropping system with and without legumes.

Objective 4. Demonstrate agronomic and economic findings to regional farmers, Extension researchers and educators, and other interested in sustainable cropping systems.

In order to stimulate additional research, enhance credibility, and increase the likelihood of acceptance by farmers, findings from this study will be disseminated in variety of ways. Research-in-progress field days and meetings will involve presentations and demonstrations by farmer collaborators and researchers. Experimental areas will be posted to promote local visibility and visitations by interested parties. For local, regional, and national exposure, agronomic results and collaborative research experiences will be documented through publications and presented at various meetings and conferences.


Click linked name(s) to expand
  • Dennis Demmel
  • Rod Devier
  • Kenneth Disney
  • Rhae Drijber
  • Scott Easterly
  • Kent Eskridge
  • Dillon Feuz
  • Charles Francis
  • James Krall
  • Drew Lyon
  • Constanza Monteleagre
  • Tom Nightingale
  • Glendel Snyder
  • Jane Sooby
  • Raymond Weed


Materials and methods:

Farmer cooperator participation

A farmer steering committee was established that consisted of three farmer cooperators and two regional farmers experienced in growing legumes. Though each collaborator was interested in trying a legume in his cropping system, none had previously done independent experimentation with legumes.

Given the time frame of the study and the availability of resources, the steering committee identified research objectives based on relevancy to production problems and the potential impact of acquired information in addressing those problems. Subsequently, during a series of meetings, collaborators and researchers discussed/formulated a research plan to accomplish these objectives, including data to be taken, field layout, consistency of protocol across locations, and long term commitment to a rotation study. The research plan was designed to be both streamlined for easiest implementation by the collaborators yet statistically sound for general acceptance by the research community. The steering committee process was evaluated by requesting participants to complete evaluation forms at the end of each meeting and throughout the course of the study.

Assess value of legume green manure

The steering committee decided to use Austrian winter pea as the study legume, since prior experiments in Wyoming indicated that it would perform well in an environment similar to that of western Nebraska. They developed objectives to assess the value of Austrian winter pea in providing nitrogen fertilizer equivalents, suppressing weed growth, preventing wind erosion, and enhancing soil organic matter and nutrient levels. As a supplement to these objectives, another goal was to determine the effect of Austrian winter pea on soil microbial activity and soil microbial numbers.

The research was conducted on each of three farmer cooperator’s farms and the University of Nebraska High Plains Ag Lab at Sidney, Nebraska. The sites, three in Cheyenne County and one in Kimball County, represented a range of soil types and rainfall in the southern Panhandle of Nebraska.

The experimental design was a split-block design with 2 or 3 replications, depending on the size of the particular study area. Main treatments were legume or fallow and split-plot treatments were five (5) nitrogen fertilization levels (0, 28, 50, 67, and 112 kg N/ha).

Residue ground cover was measured by the “line-transect method” and soil moisture was gravimetrically determined from incremental soil cores. Tests for soil organic matter, soil nutrients, plant nitrogen, and wheat protein were conducted at the University of Nebraska (Lincoln, NE) Soil and Plant Analyses Laboratory. Microbial activity and soil microbial numbers were conducted at the Panhandle Research and Extension Center (Scottsbluff, NE), by Dr. Constanza Montealegre. Analysis of variance was used to evaluate treatment differences.
At each site, data was collected during two, wheat-millet-fallow cycles. The study period, during each cycle, began with planting of the legume in year one and concluded with wheat harvest in year two. The time frame and research protocol was as follows:

Year One
In the fall (September 1-15 ), Austrian winter peas were inoculated and planted into millet stubble, with fallow plots left in stubble. Baseline soil tests were taken for soil particulate organic matter levels, pH, available phosphorus, and nitrate levels. Weed and pea biomass samples were taken in the spring (May 10-June 7) to document the competition between pea stands and weed growth and, subsequently, analyzed to determine potential, soil nitrogen contributions. Residue measurements were also taken prior to discing the peas at bud stage.

Year Two
Prior to planting wheat in the fall (September 7-20), soil samples were again collected to determine soil organic matter, pH, available phosphorus, and nitrate levels. In addition, soil samples were collected for moisture determinations, residue measurements were retaken, and dry fertilizer (ammonium nitrate) broadcast applied for establishment of experimental nitrogen levels. Wheat plots were harvested in the summer (July 4-20) and analyzed for yield and protein content.

Enterprise budget analysis

Farmer cooperators recorded market price values and costs associated with the use of a legume in their cropping system, including machinery, labor, fuel, and input costs. This information, along with yield data from the study, was analyzed by partial budget techniques. This procedure allowed for the comparison of variable costs and returns for the wheat-millet system with and without a legume.

Demonstration of results

At field days, on-farm tours, and informational meetings, both researchers and farmer collaborators have presented demonstrations of research-in-progress, discussed research findings, and shared experiences of direct involvement by farmers in designing the legume research.

Information regarding the project and its promotion was disseminated to regional farmers via television, radio, newspaper, and printed pamphlets/brochures. For local visibility, plots were located near roadways, with posted information about experimental objectives, methods, and design.

Results from the study, as well as farmer evaluations of the collaborative process, were presented at the Nebraska Sustainable Agriculture Society’s Western Conference, the main source of information on sustainable agriculture in western Nebraska.

Agronomic and economic data will be written up and submitted for publication in local, regional, and national agronomic publications.

Research results and discussion:

The first objective was to have farmer involvement in the research. The group of farmers that we interacted with were all engaged, helping design the questions that we were trying to answer, the strategies used to answer them and implementing the experiment. Each producer helped in all phases of the experiment except data analysis. The producers tended to have a quicker interpretation of the data then the researchers, feeling that with no yield benefit and increased costs, that this particular attempt to replace fallow with a legume that would provide nitrogen and increase organic matter would not work on their operations. However, they were actively engaged in what it took to do good comparison research and have moved on their own to evaluate other legumes and alternative management strategies to make them more successful. The interaction with researchers led to the understanding that sharing information was essential to making a new legume system work and led to the development of the High Plains Dry Pea Producers Association. This association is designed to provide producer t producer education on how legumes can be more successfully incorporated into the regional production system.

Averaged over years and locations wheat yields were reduced by 10% by adding Autrian winter peas to the wheat-fallow rotation. The effect of peas on wheat protein (an increase of 0.5 % crude protein) was similar across nitrogen rates up to 100 pounds per acre, where the data converged. This indicates that peas may have been beneficial in providing late season nitrogen to the system as grain fill occurred. The difference in yield response between peas and fallow increased as nitrogen rates increased indicating that water became more limiting at the higher nitrogen rates. Location and year effect were all significant for the major factors measured, but the interaction was limited to wheat yields being more similar between peas and fallow at the Devier farm than at the other locations. This was the highest rainfall location and further indicates that water becomes a limiting factor in this system.

The enterprise budget analysis that were conducted were all based on the assumption that the increased costs of producing the legume would be offset by improved yield, erosion control and organic matter. With an actual decrease in wheat yields it is difficult to assume that this is a cost effective strategy. Data was recorded to show the increase in biomass which could increase organic matter over time, and that ground cover was improved during high erosion time periods by including the legume in the system. Current market systems give no direct value to these, but it was the general impression of the producers involved that there would have to be a better way to accomplish this.

Several tours were held of the farms involved over the two year period to allow others to observe the various stages of the research. These interactive events are where the idea of forming an association were developed and the ideas for further research were defined. The actual success of demonstrating usefulness of Austrian winter peas was minimal, but the success of stimulating alternative ideas was tremendous. Several attendees came to the conclusion that spring planting rather than winter planting would work better and initiated their own on farm trials and encouraged other trials by the University researchers involved. This has led to more than 10,000 acres of production of spring planted peas in 2001. While many factors contributed to this growth from zero acres at the beginning of this project it is apparent that this project and the interaction it created were a driving force.

Research conclusions:

Because farmer collaborators were involved in this study, they have acquired a basic understanding in the design and implementation of on-farm experiments. Their involvement has resulted in increased interest and opportunity for regional producers to utilize experimental methods in evaluating the feasibility of alternative cropping systems and/or as a tool in addressing current production practices.

Producers have been made aware of the importance of organic matter as a potential nitrogen source, and the key role it plays in improving the sustainability of the family farm. Their imaginations have been challenged to see the long term potential impact of improved organic matter and decreased nitrogen cost on their farms.

This study has helped to stimulate interest in using “pulse crops” as another rotational crop in dryland cropping systems. These crops have the potential to be harvested for grain and, in addition, the remaining residue can serve to prevent soil erosion and as a source for soil nitrogen. It is expected that more than 20,000 acres of legume crops not grown at the beginning of this experiment will be grown in the region this next year.

Participation Summary
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.