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

2014 Annual 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

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


In Iowa and adjacent north-central states majority of cover crop work has been conducted in corn and soybean farming systems. Fruit and vegetable cropping systems are still lagging in efficiently integrating cover crops as a sustainable crop rotation strategy. 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 focuses on training agricultural professionals on concepts and application of cover crops in fruit and vegetable production systems.  The project will organize 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. Workshops speakers would include researchers, farmers and ranchers who have successfully incorporated cover crops in their production systems. The project will strengthen the scope of professional development activity by organizing trips to two regional fruit & vegetable conferences that include sessions on cover cropping and agricultural sustainability.

Objectives/Performance Targets

The overall objective this project is to provide a professional development and educational forum on cover crops that help create sustainable fruit and vegetable production systems. The intended audiences for the project include 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 production
  • 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


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 five 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 in 2014






Cover Crop Workshop, Kalona, IA

Cover Crops in Vegetable Production



Cover crop talk 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 Farmers Market Growers, Cresco, IA

Selecting the right cover crop in your vegetable crop rotation


 Cover Crop Field Days

Cover crop plots were established at Horticulture Research Station, Ames, IA.  The Central Iowa Agriculture Team Tour organized on 6/5/2014 brought 35 extension agents all across Iowa (Table 2). The extension staff was 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. Cover crop demonstration plots were also set up at two grower collaborator plots (Darrell Geisler, Growing Family Fun Farms, Bondurant, IA and Rinehart Farms, Ogden, IA). 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

Table 2. Cover crop Field days organized in Iowa in 2014






Central IA Agriculture Team (CIAT) tour (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 Crop Workshop and Field Day, Independence, IA

Integrating cover crops in fruit and vegetable production



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

Cover crops for school gardens


 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
Two educational /professional development trips for extension staff, agricultural educators, and leaders from grower organizations were organized to attend two 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 (9-11 January, 2014) 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 (9-11 December, 2014) visit included representatives from Practical Farmers of Iowa leaders (Chad Hensley and Ben Saunders), Iowa Fruit and Vegetable Growers Association (Mike Penick) and ISU Research and Demonstration Farm staff (Brandon Carpenter and Steve Jonas). 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. The videos were recently edited and will be made available to NC-SARE for sharing with the sustainable agriculture community.

Summer Cover Crop Research
As part of the field demonstration in 2013 Fall, a fall cover crop research experiment was set up in Ames, IA focusing 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. The treatments were chosen based on their optimal growing season as well as flexibility to fit in a vegetable crop rotation.

Cover crops put on good growth throughout the fall before going dormant for the winter. The following spring when the potatoes were well established and a weed pressure was present the weed counts were taken in representative areas of each plot. The data reveals that oilseed radish had decreased the weed populations by over 70 percent when compared to the control (Fig. 1). There was interaction between cover crop and potato cultivar. Between the two potato cultivars studied, Red Pontiac yielded better than the Yukon Gold (Fig. 2).  The decrease in the Yukon Gold yield may be attributable to the poor stand establishment.  There were no significant treatment differences on potato yield in any of the cultivar.

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.

Impacts and Contributions/Outcomes

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.

In the second year of the project, 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 in this year 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.


Dr. Thomas Kaspar

[email protected]
Senior Scientist
USDA-ARS, National Laboratory for Agriculture and the Environment
2110 University Blvd.
USDA-ARS, National Laboratory for Agriculture and the Environment
Ames, IA 50011
Office Phone: 5152948873
Dr. Gail Nonnecke

[email protected]
Iowa State University
Horticulture Hall
Department of Horticulture, Iowa State University
Ames, IA 50011
Office Phone: 5152940037