Stefan Gailans

Research and Field Crops Director

Stefan Gailans joined Practical Farmers of Iowa in August 2013. An agronomist by training, Stefan’s primary responsibility is to manage the Cooperators’ Program, Practical Farmers of Iowa’s vehicle for conducting on-farm research on the issues and concerns deemed most important by our members. He also coordinates field days, conference sessions and work shops for PFI’s field crops program.

Stefan received his Ph.D. in Crop Production and Physiology & Sustainable Agriculture from Iowa State University in 2017. His primary research interests were cover crops, third crops and diversified crop rotations. He now looks forward on a daily basis to working with farmers across the state to address these very same research concerns.

Stefan grew up in southeast Wisconsin, but he has enjoyed calling Ames (and Iowa!) his home for over 10 years. When he’s not thinking about crops, you can find Stefan hunting, fishing, gardening, reading science fiction or listening to Iowa Public Radio. Stefan also currently serves as board president at Wheatsfield Cooperative Grocery, a community-owned full-service grocery store specializing in fresh, local and organic food and services in Ames.


Blog posts

Cover crops are typically either aerially seeded into standing crops around the time of physiological maturity in late summer or drilled immediately following crop harvest in the fall. However, on occasion time does not permit one to get a cover crop seeded in the fall or the cover crop fails to establish.

In 2017, farmer-researchers Jeremy Gustafson and Chris Teachout evaluated spring cover crops that were seeded in March approximately 50 days before planting soybeans later in the spring.

Read the full report here: Spring-Seeded Cover Crops Ahead of Soybeans.

spring-seeded covers cover shot

How Was the Trial Conducted?

Jeremy Gustafson conducted a trial in one field where he seeded oats. Chris Teachout conducted trials in two separate fields where he seeded two different cover crop mixes. See the table below for cover crop and soybean management at the two farms. Continue reading

In Iowa, cover crops are typically either aerially seeded into standing corn around the time of physiological maturity in late summer or drilled immediately following corn harvest in the fall. However, the earlier one can seed a cover crop, the more potential for growth and biomass production. An earlier seeding date also opens up the opportunity for more diverse cover crops like brassicas and legumes that need more time and heat units to grow than common cover crops like cereal rye.

Farmer researchers Jack Boyer and Jeremy Gustafson interseeded cover crops (cowpeas, annual ryegrass, rapeseed) into corn at the V4 stage in June. Corn hybrids chosen exhibited vertical and horizontal leaf orientations to test whether more light penetrating the corn canopy would encourage successful cover crop establishment and growth.

Read the full report here: Corn Leaf Architecture for Interseeded Cover Crops.

Interseeding cover crops cover shot

How Was the Trial Conducted?

  • Corn planting date (both hybrids): Boyer = Apr. 25; Gustafson = May 5
  • Cover crop mix interseeding date: Boyer = June 14; Gustafson = June 16
  • Cover crop mix seeding rates: Cowpeas (60 lb/ac); annual ryegrass (22 lb/ac); rapeseed (7 lb/ac)
  • Corn harvest date (both hybrids): Boyer = Nov. 4; Gustafson = Oct. 25

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A roller-crimper presents farmers the opportunity to mechanically terminate cover crops without chemicals or tillage. This method is dependent on a large amount of cover crop growth and the cover crop reaching the flowering stage before crimping. A roller-crimper is a large, metal cylinder with “chevron” pattern blades that simultaneously lays the cover crop flat on the ground and crushes the stem in several places. Successful termination of a cover crop with the roller-crimper is dependent on the cover crop being at the anthesis (flowering) stage at the time of rolling. For cereal rye, this flowering stage is likely to occur in late May in Iowa.

Farmer-cooperator Tim Sieren compared soybean seeding dates relative to cover crop termination (before and after) as well as cover crop termination techniques (chemical vs. roll-crimp). “If I can manage a roller-crimper system in soybeans, while maintaining yields,” Sieren said, “I could drastically reduce herbicide use.”

Read the full report here: Roll-Crimping Cover Crops and Soybean Seeding Date.

Rolling covers and soy seeding date cover

How was the trial conducted?

This trial was conducted by Tim Sieren of Green Iron Farm near Keota in Washington County. Treatments included:

  • Plant-then-spray: plant soybeans (Apr. 24), then spray the cover crop (May 5)
  • Spray-then-plant: spray the cover crop (May 5), then plant soybeans (May 7)
  • Plant-then-roll: plant soybeans (May 7), then roll the cover crop (May 30)
  • Roll-then-plant: roll the cover crop (May 30), then plant soybeans (May 30).

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How does a cover crop affect corn and soybean yields? Winter Cereal Rye Cover Crop Effect on Cash Crop Yield: Year 9 is now available! This is a long-term project being conducted by Iowa Learning Farms and Practical Farmers of Iowa. Between 2009 and 2017, 12 farmer-cooperators have contributed to 63 site-years of on-farm research to investigate what effect a cereal rye cover crop might have to yields of corn and soybeans.

A no-cover (left) and cover (right) strip at Kelly Tobin's on Apr. 20, 2017.

A no-cover (left) and cover (right) strip at Kelly Tobin’s near New Market on Apr. 20, 2017.

Over the course of this project, farmers reported that in 59 of 63 site-years, properly managed cover crops had no negative effect on corn and soybean yields. Of those 59 site-years, soybean yields were improved by cover crops in 8 instances and corn yields were improved in 2 instances (both occurring in 2016). Continue reading

Successfully raising corn after a cover crop requires timely cover crop termination and N fertilization. Commonly, farmers terminate a cover crop 2-3 weeks prior to planting corn but generally do not need to apply any more N than if they did not use a cover crop. Last year, PFI farmer-cooperator Dick Sloan attempted “planting green”: planting his corn into a cereal rye cover crop that was terminated just two days prior. In Sloan’s case, he saw a 5 bu/ac yield reduction compared to where he terminated the cover crop two weeks prior to planting corn yet stands were equal between the two treatments (Cover Crop Termination Date Ahead of Corn). This past growing season, farmer-cooperators Dick Sloan and Tim Sieren compared terminating their cover crops approx. 3 weeks prior to planting corn with terminating their cover crops within 3 days of planting corn. They also investigated N fertilizer timing and rates across the cover crop termination dates.

You can read the full report of this project here: N Fertilizer Strategies for Corn Following Cover Crop.

N fert strategies 2017 cover shot

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Cover crops are gaining new attention for their ability to reduce weed pressure in soybeans. Specifically, when seeding soybeans directly into a thick cover crop. In the past two years, farmer-researchers Jeremy Gustafson and Jack Boyer have documented reduced herbicide use when planting soybeans into a tall, thick cereal rye cover crop that they chemically terminated near the time of soybean planting (Cereal Rye Cover Crop Termination Date Ahead of Soybeans). In this new project, farmer-cooperators Jack Boyer and Scott Shriver investigated the effect of row-width on soybean yields when rolling a cereal rye cover crop. Boyer rolled select strips after terminating with an herbicide; Shriver used a roller-crimper to terminate his cover crop.

You can read the full report of this project here: Rolling Cover Crops and Soybean Row-Width.

Rolling covers and soy row-width cover

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Cover crops in Iowa are typically seeded in late summer or fall. The most common cover crops are winter small grains like cereal rye or winter wheat. But farmers are increasingly interested in diversifying the cover crop portfolio in Iowa. In this trial, cooperators wondered: Can frost-seeding small-seeded brassica species into crop residue be an effective spring cover crop strategy? Because mustard and rapeseed have relatively small seeds, some have wondered if frost-seeding these into crop residue in the early spring could be an effective 40- or 50-day cover crop strategy. Read the new report here: Spring-Seeded Brassica Cover Crops.

Kodiak brown mustard at Jeremy Gustafson's on Apr. 24, 2017. Seeded on to soybean stubble on March 2.

Kodiak brown mustard at Jeremy Gustafson’s on Apr. 24, 2017. Seeded in to soybean stubble on March 2.

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Continuing work from the previous two years, Practical Farmers of Iowa and partners conducted another round of oat variety trials in 2017. Fifteen varieties were screened at two Iowa State University research farms (Kanawha, Nashua) and one PFI farmer-member farm (Wayne Koehler, Charles City)  Find the new report here: Oat Variety and Fungicide Trials 2017.

Alert Smith 2015 (194)

Key Findings:

  • The variety Antigo had the highest test weight at each location (>38 lb/bu) but was also among the lowest yielding varieties. Reings scored a test weight of 38 lb/bu at Kanawha
  • Application of fungicide did not improve oat yield or test weight for the four varieties tested at Nashua

Learn more about this project below.

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For those who missed the field day on soil regeneration hosted by Chris & Janenne Teachout near Shenandoah on Aug. 29, or for those who want to re-acquaint themselves with some of it, check out the “highlight reel” we’ve compiled below. The video features Chris, as well as Dr. Jill Clapperton, discussing cover crop practices and benefits to soil health.

Find more images from this excellent field day below.

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In Iowa corn-soybean production systems, cover crops are typically aerially seeded into standing crops around the time of physiological maturity or drilled immediately following corn or soybean harvest. Previous on-farm research conducted by Jack Boyer has shown that seeding cover crops earlier in the fall can translate to greater fall and spring biomass. This may present the opportunity for more diverse cover crop species selection. With this in mind, farmer-cooperator Jon Bakehouse wanted to investigate how he could seed cover crops earlier than normal in a corn-soybean system and more successfully include a diverse array of cover crop species. To accomplish this, Jon planted early maturing varieties of corn (104- or 105-day) and soybean (1.0 group) in an attempt to harvest earlier in the fall and seed cover crops earlier in the fall.

You can read the full research report here: Accommodating Cover Crops with Early Maturing Corn and Soybeans.

Early maturing soybeans in the center strip with later maturing beans in the outer strips at Jon Bakehouse's in Sept. 2015.

Early maturing soybeans in the center strip with later maturing beans in the outer strips at Jon Bakehouse’s in Sept. 2015.

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