Educating Agricultural Professionals and Extension Educators in Developing Sustainable and Resilient Cropping Systems through Integration of Cover Crops

Final Report for ENC12-132

Project Type: Professional Development Program
Funds awarded in 2012: $59,296.00
Projected End Date: 12/31/2014
Region: North Central
State: Iowa
Project Coordinator:
Dr. Ajay Nair
Department of Horticulture, Iowa State University
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Project Information


Enhancing soil quality and health is critical when building a sustainable cropping system. Cover crops play an important role in improving several soil properties and overall ecological sustainability. There has been an increase in fruit and vegetable growers who utilize cover crops in some form or the other in their cropping systems. With growing demand for sustainably grown produce, growers require information on types of cover crops, their growth stages, management techniques, and potential challenges associated with their use. Growers need extension specialists and agricultural educators with knowledge and skills to assist them in implementing a sustainable farm plan integrating cover crops. This project trained agricultural professionals and extension personnel on concepts and application of cover crops in fruit and vegetable production systems.  The project organized several statewide cover crop training workshops and field days for Commercial Horticulture Field Specialists, County Horticulturists, and members of organizations such as Iowa Department of Agriculture & Land Stewardship, Regional Food Systems Working Group, Iowa Fruit & Vegetable Growers Association and Practical Farmers of Iowa. The project also offered professional development opportunity to extension and industry personnel by organizing trips to two regional fruit & vegetable conferences that include sessions on cover cropping and agricultural sustainability. Evaluation and feedback of program participants indicate knowledge gain and increased interest in sustainable production systems. The project also involved growers and community leaders from the Amish and Mennonite community and educated them on the proper planting, management, and termination techniques of cover crops. Several multimedia videos an extension publication was developed to widen project outreach and impact.

Project Objectives:

The overall objective of this project was to provide a professional development and educational forum
on cover crops that help create sustainable fruit and vegetable production systems. The audience for the project included extension personnel from Iowa State University, University of Missouri, Lincoln University, Iowa State University Research & Demonstration Farm superintendents, county extension personnel, government agency staff, leaders of grower organizations, and staff from Natural Resource Conservation Service. Core objectives of the
project are to:
• Highlight the importance of cover crops in fruit and vegetable production systems.
• Provide a platform to share resources, knowledge, and expertise in the area of cover cropping
in fruit and vegetable production.
• Promote hands-on learning opportunity to better understand cover cropping practices
• Connect agricultural educators to professionals in the area of sustainable fruit and vegetable
• Develop a brief and concise extension bulletin that can be interpreted and used by extension
staff, agricultural professionals, and the end client (fruit and vegetable growers).
• As a long term strategy, facilitate integration of cover crops into fruit and vegetable
production systems to create diverse and resilient cropping systems.


Grower organizations such as Iowa Fruit and Vegetable Growers Association (IFVGA) and Practical Farmers of Iowa (PFI) are strong advocates of farm sustainability and have called for research and outreach programs that focus on successfully integrating cover crops in fruit and vegetable production. Currently fruit and vegetable growers usually have to search out information and educational materials and rely on their own time consuming investigations to
understand principles and practices of cover cropping. Without understanding these principles and cropping system specific information it is difficult for growers to choose, grow, and manage specific cover crop types suitable for their production systems in Iowa. They need to identify the appropriate cover crop species, its growth characteristics and pattern, when and how to seed, when and how to terminate, and potential challenges and issues associated with them. Poor planning and decision making could attract pests and diseases, affect nutrient cycling, result in
cover crop failure, negatively affect performance of main crop, and lead to economic losses.

Every cover crop species has its own niche and attributes for agricultural production. A wrong combination of cover crops may exert negative attributes, so a thorough understanding of cover crops selection and management is needed to minimize negative outcomes. Extension personnel and growers surveyed during a cover crop session at the 2012 Iowa Fruit and Vegetable Growers Conference, Ankeny, Iowa expressed great interest in learning more about cover crop options in fruit and vegetable production systems. The session clearly indicated the need for capacity building and development of applied research, education, and training programs for beginning and
current growers to help them better understand use of cover crops. A follow-up to this event was a focus group meeting with two vegetable growers in Boone, which led to establishment of two on-farm cover crop crop studies in Spring 2012, 2013, and 2014. 

In Iowa, significant work has been done in integrating cover crops into corn and soybean cropping systems, however, much work is needed to increase cover crop utilization in fruit and vegetable production systems. Fruit and vegetable growers need extension specialists and agricultural educators with knowledge and expertise in cover cropping. Although extension specialists and educators are available to offer assistance, they need continuing education for
providing new relevant information on types of cover crops, their growth stages and life cycles, planting time, and management techniques. Extension personnel and agricultural professionals who are trained about cover crops, their advantages, and any potential challenges associated with cover cropping are more likely to assist growers interested to adopt cover cropping.


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  • Dr. Thomas Kaspar
  • Dr. Gail Nonnecke

Education & Outreach Initiatives



The overarching goal of this project was to educate growers, extension personnel, university faculty and staff, graduate students, industry groups, and grower organizations about the benefits and importance of cover crops in specialty crop production. To accomplish this goal we organized a series of cover crop workshops and field days, on-farm demonstration trial, and a research experiment focusing on the integration of summer cover crops in fall lettuce production. Below are details of various activities undertaken:

Cover Crop Workshops
Given the growing interest in cover crops in Iowa, project organized several cover crop workshops across Iowa. Details of those workshops are provided in the Table 1. Audience included commercial horticulture field extension specialists, county extension horticulturists, and regional food systems working group members, local food organizations, Iowa Fruit and Vegetable Growers Association and Practical Farmers of Iowa board members, and Iowa Department of Agriculture and Land Stewardship and NRCS personnel. Based on response obtained from the Amish community in Kalona, IA the February workshop was scheduled to take place in Kalona, IA so that more people from the community could attend. Topics covered during the three hour workshop included cover crop types, planting, management, benefits, and issues associated with cover cropping in fruit and vegetable cropping systems. Workshops speakers highlighted advantages of cover crops in sustainable crop rotations and their ability to improve soil quality, reduce soil erosion, increase fertility, and manage pest populations. Thirteen types of cover crops grown in 3 ft. by 1.5 ft. flats were also exhibited during the workshop for participants to evaluate the morphology, structure, and growth characteristics of cover crops.

Table 1. Cover crop workshops organized in Iowa






SARE PDP Cover Crop Workshop, Mason City

Successful integration of cover crops in vegetable production



Cover Crop Workshop, Kalona, IA

Cover Crops in Vegetable Production systems



Intro to cover crop for market gardeners, Columbus Junction, IA

Cover crop options for vegetable production



Northeast Research Farm Field Day, Nashua, IA

Cover crop for backyard and community gardens



Cover Crop Workshop and Field Day, Independence, IA

Integrating cover crops in fruit and vegetable production



Cover Crop Workshop, Sioux City, IA

Improving soil quality with cover crops in vegetable production



Cover Crop Workshop for Market Growers, Cresco, IA

Selecting the right cover crop in your vegetable crop rotation



Grower discussion at Great Plains Growers Conference, St. Joseph, MO

Summer Cover crops in fall veg production



Cover Crop Panel, Practical Farmers of Iowa

Update and discussion on cover cropping in Iowa



Roundtable discussion, Iowa Fruit and Vegetable Growers Conference

Cover crops in high tunnels



Workshop at Cedar valley Produce Auction, Elma, IA

Cover crops to improve soil quality in vegetable cropping system


Cover Crop Field Days

Cover crop plots were established at Horticulture Research Station, Ames, IA.  One of the highlights is the ‘Train the trainer’ cover crop workshop organized for the Central Iowa Agriculture Team Tour organized on 6/5/2014. The event brought 35 extension agents all across Iowa (Table 2). The extension staff were provided in-depth information planting and managing cover crops in Iowa. Participants got an opportunity to observe cover crops in the field, dig them out to study root structure, and learn about crop morphology and growth. This exercise facilitated better understanding of cover crops among participants.

Table 2. Cover crop Field days organized in Iowa in 2013, 2014, and 2015






MIRF Field Day

Cover crops for weed suppression in cucurbit production



Fruit and Vegetable Field Day

Sweet potato, pepper, carrot, tomato



SARE PDP Cover Crop Field Day, Atlantic, IA

Introduction and basic of cover cropping



SARE PDP Cover Crop Field Day, Ames, IA

Cover Crops in Vegetable Production



SARE PDP Cover Crop Field Day, Fruitland, IA

Cover Crops in Vegetable Production



Central IA Agriculture Team (CIAT) tour (ISU Extension staff)

Cover crops and Conservation tillage in organic vegetable production



Cover crop Field Day, Ames, IA

No-till broccoli and pepper production



Grower Field Day, Growing Family Farms, Bondurant, IA

Strip till pumpkin production



Cover crops for kids, Riverside Elementary School, Sioux City, IA

Cover crops for school gardens



Cover Crop Field Day, Fruitland, IA

Legume cover crops in vegetable crop rotation



2015 Fruit and Vegetable Field Day, Ames, IA

Summer cover crops for Midwestern vegetable production systems


Cover crop demonstration plots were also set up at grower collaborator plots (Darrell Geisler, Growing Family Fun Farms, Bondurant). A field day focusing on strip till pumpkin production was hosted at the Darrell Geisler’s farm which was attended by local growers and ISU Extension and Outreach staff. This Field Day was sponsored by the Iowa Fruit and Vegetable Growers Association. Two summer/fall cover crop on-farm trial were also set up which led to adoption of cover crops by grower participants (Table 3).

Table 3. On-farm grower collaborator trials


Cover crops tested

Greg Rinehart, Ogden, IA

Oilseed radish and yellow mustard

John Kroul, Mt. Vernon, IA

Buckwheat, oilseed radish, yellow mustard

Scott Wilber, Boone, IA

Oilseed radish and yellow mustard

In 2014, the project expanded its outreach beyond extension staff and growers and included high school and elementary school students and teachers. Cover crop seeding demonstrations were held at Independence High School, Independence, IA and the Riverside Elementary School, Sioux City, IA. At Independence, school authorities were interested in setting up a vegetable plot for students to gain production experience and also use the produce for their school kitchen. At Riverside Elementary School, cover crop seeding demonstration complemented their learning module which taught students about the importance and soil and soil conservation in modern day agriculture. 

Professional Development
Educational /professional development trips for extension staff, agricultural educators, and leaders from grower organizations were organized to attend regional fruit and vegetable conferences [Great Lakes Fruit, Vegetable and Farm Market Expo (GLEXPO) and Great Plains Growers Conference, Missouri]. The Great Plains Growers Conference, Missouri had educational tracks that covered several topics such as advanced soil management, nutrient management in fruit and vegetable production, and marketing of fruit and vegetables. The GLEXPO visit included representatives from Practical Farmers of Iowa leaders (Chad Hensley Ben Saunders, Susan Jutz, Kate Edwards, and Tony Thompson), Iowa Fruit and Vegetable Growers Association (Denise O’Brien, Scott Wilber, Greg Rinehart and Mike Penick) and ISU Research and Demonstration Farm staff (Brandon Carpenter, Steve Jonas, and Nick Howell).

Table 4. Participants for professional development trips to Great Lakes Expo, Michigan and Great Plains Growers Conference, Missouri.



Denise O’Brien

Founder, Women Food and Ag. Center, Atlantic , IA

Scott Wilber

Secretary, IFVGA

Greg Rinehart

Board member, IFVGA

Mike Penick

Board member, IFVGA

Chad Hensley

Practical Farmers of Iowa (PFI)

Ben Saunders

Practical Farmers of Iowa (PFI)

Susan Jutz

Past President, Practical Farmers of Iowa (PFI)

Kate Edwards

Practical Farmers of Iowa (PFI)

Tony Thompson

Practical Farmers of Iowa (PFI)

Brandon Carpenter

Field Specialist III, ISU Research and Demonstration Farms

Steve Jonas

Manager, ISU Composting Facility; Grower, Red Granite Farm

Nick Howell

Superintendent, ISU Horticulture Research Station

Joseph Hannan

Horticulture Field Specialist, ISU Extension and Outreach

Patrick O’Malley

Horticulture Field Specialist, ISU Extension and Outreach

Jim Cherry

Grower and Community leader, Ventura, IA

We strongly believe that extension personnel and grower organization representatives should be kept abreast with the latest developments and advancements in cover crop research and technology and the GLEXPO visit was an excellent step in that direction.

Cover Crop Educational Videos
As part of field days, three cover crop videos were created which highlighted the importance of short duration summer cover crops that could be incorporated in vegetable cropping systems. Videos are available on NC SARE website. Graduate students played a key role in participating in those videos and also helping with the planting, maintenance, and analysis of data.

Fall and Summer Cover Crop Research
The project took advantage of the cover crop demonstration plots that were established for field days. Two experiments were conducted focusing on summer and fall cover crops. The fall cover crop research experiment focused on effects of fall seeded cover crop on spring potato production. The three cover crops studied were: Cereal Rye, Oilseed Radish, and Crimson Clover. The control treatment for the study was a no-cover crop plot. The study investigated the cover crop effect on two different potato cultivars (‘Red Pontiac’ and ‘Yukon Gold’) that are popular cultivars among Iowa growers. Cereal rye and oilseed radish cover crops produced higher biomass than crimson clover. Late fall, crimson clover and no-cover crop had similar weed population densities, but oilseed radish was lower. In early spring, cover crops reduced weed population density compared to no-cover crop treatment. At the time of cover crop termination in spring, crimson clover increased whereas cereal rye decreased soil nitrogen concentration over no-cover crop treatment, however, this effect was not observed after cover crop termination. Cover crops did not affect final potato yield but the ‘Red Pontiac’ yield was significantly higher than ‘Yukon Gold’. Overall, the study demonstrates positive effects of cover crops on weed population suppression during cover crop growth. Cover crops did not negatively impact potato yield or quality.  Results from this study show promise in the area of weed management using cover crops. Cover crops, in addition to adding organic matter, can reduce weed populations and lower the amount of herbicides in vegetable production systems.

The summer cover crop research experiment focused on effects of summer cover crop on fall lettuce (cultivar Nancy) production. Treatments tested included buckwheat, cowpea, sorghum sudangrass, and no-cover crop. Cover crops provided excellent weed control and generated large amount of biomass (Sorghum Sudangrass - 4,739 lb/A; Cowpea - 1,130 lb/A; Buckwheat - 1,800 lb/A). Sorghum sudangrass and buckwheat produced significant biomass but did not benefit the following lettuce crop. There were no marketable lettuce heads from the sorghum sudangrass plots. This could potentially be due to allelapathic effect of sorghum sudangrass or nitrogen tie up by the decomposing cover crop. Cowpea increased both number and weight of marketable lettuce heads. As a legume cover crop cowpea has the potential to fix atmospheric nitrogen. Short duration cover crops, thus, are excellent choices as tools for crop rotation, weed suppression, and crop diversification.

Outreach and Publications

Extension publication
A cover crop extension bulletin was developed titled ‘Cover crops in vegetable production systems’. This bulletin has been downloaded 622 times from ISU Extension and Outreach website. Also this publication was included in a monthly print-only publication for Amish communities, with a circulation of 7,500, primarily in Pennsylvania and Ohio.

Research publication
The research conducted on the impact of summer cover crops on lettuce production has been accepted for publication in HortTechnology pending revisions. The article is titled ‘Summer cover crops and lettuce planting time influence weed population, soil nitrogen concentration, and lettuce yields’.

Outcomes and impacts:

Growers who attended cover crop field days/workshops and advanced high tunnel workshops gained significant information and knowledge about cover crops. The pre-workshop evaluation showed most participants in the ‘low’ to ‘moderate’ range of knowledge, but the post-workshop evaluation shifted to ‘moderate’ to ‘high’ range. Fruit and vegetable growers who attended the cover crop field day got an opportunity to see various cover crop species in the field. Growers assessed growth and development of cover crops and evaluated potential benefits such crops on soil nutrient cycling, quality, and health.

This grant also included an on-farm demonstration of cover crops with a grower collaborator in Ogden IA (Greg Rinehart, Rinehart Farms, Ogden, IA). Yellow mustard and oilseed radish cover crops were grown along with an unseeded control. Data were collected on cover crop biomass and soil nutrient status. This was the first brassica cover crop ever planted by this producer. The experiment gave him an opportunity to understand brassica cover crops and possibly find ways to integrate them into his cropping system. Observations made during the study indicate increased bee activity in cover crop plots and high biomass production. A significant impact of this on-farm study was the adoption of cover cropping practice by the grower. Based on results from 2013 and 2014, the grower planted 90 acres of oilseed radish as a cover crop to reduce nitrate leaching and suppress soil erosion at his farm. This is a significant achievement and a strong action outcome for this project. Cover crops not only improve soil fertility, but they also reduce soil erosion and nutrient leaching which is the heart of Iowa’s Nutrient Reduction Strategy,  designed to direct efforts to reduce nutrients in surface water from both point and nonpoint sources in a scientific, reasonable and cost effective manner.

Involvement of Amish and Mennonite community
The project organized a cover crop workshop in Kalona, IA that was mainly catered to the Amish and Mennonite growers and leaders of that community. Cover crop field guides, cover crop extension publications, and other educational materials were distributed to growers. In addition, special arrangements were made to bring growers from these communities to attend a Field Day at the Muscatine Island Research farm, Fruitland, IA. The project was successful in addressing cover crop related questions and concerns which these growers had. In Iowa, there has been a significant increase in the vegetable acreages that are being farmed by Amish and Mennonite growers and most of them use cover crops to main soil fertility and crop productivity.   

Cover crop workshops, field days, on-farm trials, and professional development trips exposed the target audience to cover crops and the endless possibilities of using them in current fruit and vegetable cropping systems. Some of the key outcomes of this project include

  1. Creation of educational videos on cover cropping for extension and grower audience
  2. Broader impact by including participants from underserved communities such as the Amish and Mennonite communities from Kalona, IA.
  3. Further research on the effect of fall seeded cover crops on spring planted vegetable crops.
  4. Building capacity by training and exposing ISU Extension and Outreach staff on the use of cover crops in vegetable and fruit cropping systems.
  5. On-farm trials that led to adoption of cover crops by a vegetable producer.
  6. Professional development opportunities for industry leaders, grower organization representatives, community leaders, and Iowa and Missouri Extension staff.

Project Outcomes

Project outcomes:

The project adopted a comprehensive approach and included a number of key grower organizations, community leaders, researchers, and extension personnel from Iowa, Missouri, and Michigan. Field days, workshops, conference trips, and meetings provide an excellent setup for all participants to learn, engage, and discuss cover crops in fruit and vegetable cropping systems. A total of 10 participants from Missouri Extension and Lincoln University participated in a Field Day/Workshop at the Horticulture Research Station. Participation of extension and university researchers from Missouri added value, wider impact, and enriched the content of the cover crop program by addressing diverse landscapes, soil types, and agro-climatic zones with respect to seeding, establishing, and maintaining cover crops in fruit and vegetable cropping systems.


Future Recommendations

The project was successful in reaching its goals of training agricultural professionals on concepts and application of cover crops in fruit and vegetable production systems. Statewide cover crop training workshops and field days allowed for hands-on learning opportunities. As the scope and importance of cover crops increases it will be useful to test the establishment and performance of non-traditional cover crops in the Midwest region. Growers and extension professional will benefit if cover crops could be made more tangible for example how much money could one save in N inputs by using leguminous cover crops, how much less herbicides are used,  and more cost benefit scenarios of different cover crops. 

With respect to the information dissemination, it would be helpful if NCR SARE could assist with organization of one or two webinars for the project coordinators to share results, accomplishments, outputs, etc. with SARE PDP administrators, extension staff, grower organizations, and agriculture entrepreneurs. This will be an opportunity for project coordinators to share education materials (web links, pdf, charts, etc.) with fellow researchers and extension staff in the NCR region

Information Products

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.