By Jim Jordahl
A one-day, deep dive into cover crops for more than thirty ag retail managers and their agronomists was held at the Iowa Soybean Association in March. This in-depth workshop was designed to help ag retail agronomists field questions on cover crops and soil health from their farmer-customers. The workshop featured top national experts and leading farmers on the use of cover crops to build soil health and improve water quality.
Sean McMahon, Iowa Agriculture Water Alliance (IAWA) Executive Director, set the theme of the meeting by sharing the advice of hockey icon Wayne Gretzky to ‘skate to where the puck is going to be’ in terms of the rising importance of cover crops and soil health to a variety of audiences, including farmers, consumers and food and beverage companies. McMahon also discussed economic opportunities for ag retailers to increase their market share and improve customer satisfaction by offering cover crops services in addition to conventional agronomic services.
The event was co-sponsored by IAWA and the USDA-Sustainable Agricultural Research and Education (SARE) program and organized by Dr. Rob Myers of the North Central regional office of SARE and professor of agronomy at the University of Missouri. Certified Crop Advisors (CCAs) earned 6 continuing education credits (CEU’s) for attending the workshop.
The Business of Cover Crops: Trends and Opportunities
Dr. Myers described the dramatic increase in cover crops acreage across a wide swath of the U.S. over the past few years. Although the 2017 Census of Agriculture showed Iowa to be one of the top states in terms of total acreage of cover crops, the percentage of total cropland with cover crops remains at only approximately 4% – thus Iowa has a lot of room to grow cover crops acreage. He noted that cover crops acreage nationwide grew by an average of 8.4% compounded annually from 2012 to 2017, while Iowa’s cover crops acreage grew by 156% - the highest growth in the nation by percentage. If these growth rates continued to 2029, cover crops nationwide would become a $1B industry, requiring over 1M acres devoted to cover crops seed production.
The ag retail sector has opportunities to take advantage of this growth and create business opportunities by:
- Selling cover crop seed to farmer customers.
- Providing management advice on cover crops, including adjustments in fertility management.
- Providing cover crops seeding services with high clearance rigs or other broadcasting equipment such as dry fertilizer spreaders. It was noted that seeding with dry fertilizer spreaders requires close attention to the time that cover crop seeds are mixed with high salt content fertilizers.
- Provide cover crops termination service.
- Helping farmers manage and monitor changes in soil health.
Establishment and Termination Tips with Cover Crops
Steve Groff, a Pennsylvania farmer and recognized global authority on cover crops provided a wealth of information to support good decisions in the critical phases of cover crop establishment and termination. Key points included:
- Shift to the mindset of ‘how will I get more life in the soil’? ‘How can I mimic nature’?
- Acknowledge that soil health can’t be bought. It has to be made through management.
- Treat cover crops like cash crops, because the profit is in the management.
- Keep increasing cover crops acreage. Steve recommends farmers increase acreage by up to 10% per year to avoid costly mistakes and indicated that CCAs support this approach.
- When seeding in the fall, every day of delay makes a difference. Agronomists should work with their farmer customers on creative approaches to get cover crops seeded early for maximum benefit.
- The window for seeding into a standing soybean crop is narrow – too early, and cover crops are shaded out. Too late, and seed may just lay on top of fallen soybean leaves.
- Termination spraying should be closely coordinated with planting plans and expected weather. Farmers should be in a position to plant what is terminated BEFORE the next rain. If it turns wet immediately after termination but before the row crop is planted, the soil dries very slowly and it takes a long time before it is fit again to plant.
- Fields planted green should be sprayed before emergence.
- Early termination of cereal rye improves the timing of nitrogen availability to corn.
- Clover is not easy to kill with glyphosate alone. What may appear to be an allelopathic effect in corn is more likely a nitrogen management issue.
Making Recommendations on Cover Crop Species and Mixes
- The goal and management considerations are important drivers for cover crop species selection. Erosion control? Forage? Soil health? Soil compaction? Soil type? Nitrogen source? Weed control? Planting method? Termination method? Seed cost?
- The timing of nutrient release is a consideration with selecting cover crop species. Radish, a non-winter-hardy species, scavenges nutrients very effectively but can release accumulated nutrients too early in the spring. A mix of species with different uptake and release characteristics can be used to help manage these effects.
- There are some helpful allelopathic effects from cereal rye on weeds, particularly small seeded broadleaves.
- Seed quality matters. Cheap and readily available seed does not necessarily (and probably does not) equal a good deal.
Iowa Experiences with Cover Crops
The workshop included a panel discussion with Mark Mueller, a Waverly, Iowa, farmer and Jason Gomes of North Iowa Agronomy partners (NIAP). Mark noted that with the improved trafficability of his fields with cover crops, he is able to spray on the rare but crucial calm days that may follow a wet period when those with conventionally tilled fields and no cover crops can’t turn a wheel. This is also a key advantage for ag retailers, who may seek out producers with cover crop fields to spray when they would otherwise be idle, waiting for fields to dry. Jason noted that producers can’t count on cover crops necessarily ‘paying their way’ every single year, but it is important to focus on the wide array of benefits, and not just the costs.
Steve Groff is recognized as one of the top U.S. experts on cover crops, having used them on his own farm for over 25 years. He has spoken on cover crops all over the world and is known as a highly effective educator on cover crops, addressing both tips for success and potential pitfalls.
Dr. Rob Myers is an agronomist at the university of Missouri and serves as the national cover crops and soil health liaison for the USDA-SARE program.
Jo LaRose is a University of Missouri extension educator with an M.S. in entomology. He has developed particular expertise on potential issues with cover crops related to slugs, voles, and other pests, and also how they impact pollinators and wildlife.
Alan Weber is a consulting ag economist who has worked with the SARE program to develop a national report on cover crop economics and on past survey efforts. He also operates an 800 acre grain and beef farm in west central Missouri where he uses cover crops for soil improvement and grazing.
Dr. Todd Peterson is a consulting agronomist who works with ag retail agronomists on practices that build soil health and reduce nutrient losses. He has a diverse background in both the public and private sector, having worked at Pioneer Hi-Bred, Land O’Lakes, The Nature Conservancy, and the University of Nebraska.
Panelists were Jason Gomes, owner of NIAP, independent crop consultant, CCA, and TSP; Mark Mueller, an Iowa producer.