Farmer-led research has been at the core of Practical Farmers of Iowa’s work since 1987. It’s continued and thrived since, with 14 master researchers, 241 total PFI cooperators and 1,443 on-farm trials. Entering the new decade of the 2020s, PFI takes a look back at what it’s learned during the last 10 years of trials.
In no particular order, follows is some of the best research from PFI’s Cooperators’ Program for the 2010s:
1. Planting corn in 60-inch row widths for interseeding cover crops. One of the first articles PFI published was on this. Conducted by Iowa cooperators Fred Abels of Holland, Jack Boyer of Reinbeck, Brian and Heather Kessel and Jim Johnson of Lamoni, and Chris Teachout of Shenandoah, these farmers were interested in whether it was possible to grow a diverse mix of cover crop biomass in extra-wide corn rows without compromising yield.
Farmers interseeded into V4 corn and evaluated the effect of planting corn in 30- and 60-inch row widths on corn yield and biomass production by cover crops interseeded to corn in early June. Seeding a cover crop in early June provides an opportunity for unique cover crop biodiversity.
The results were mixed, with Boyer and the Kessel-Johnson team not seeing an effect on yield, while Abels and Teachout had 30% and 6% yield loss, respectively. The 60-inch rows enabled sunlight to penetrate through the corn canopy to grow more cover crop biomass, potentially providing more soil fertility and the opportunity to graze after corn harvest.
2. Economic impact of grazing cover crops in cow-calf operations. Justifying the costs of establishing a cover crop and not seeing short-term economic return can be deterrents to some farmers. One way to more quickly offset those costs is to graze cover crops, reducing the cost of other potential cattle feed like hay or silage. Wesley Degner of Lytton, Bill Frederick of Jefferson and Mark Schleisman of Lake City examined the possible economic returns that grazing cover crops has in their cow-calf operations.
This project showed that cover crops as forage does have short-term economic benefits that can be reaped in the first year of cover crop establishment. “Putting cows on cover crops makes the practice worth it, and I probably wouldn’t do much cover cropping if I didn’t reap these benefits,” Degner says.
3. Winter feed monitoring on a grass-fed cattle farm. Feeding cattle in a grass-fed system can be a challenge in the winter. Grass-fed cattle farmers Dave and Meg Schmidt of Exira would prefer to get through the winter without spending large amounts on hay. They took the plunge on this research project to find the best way to reduce winter feed costs for their grass-fed herd. The Schmidts managed pastures and other farm ground a few different ways to help mitigate costs, including feeding hay, grazing cover crops and crop residue, and stockpiling pastures.
After their cover crop applicator couldn't fly on seed in the winter of 2015-16, the Schmidts were forced to feed 81% hay. The next winter, they planned accordingly and stockpiled pasture. The combination of stockpiling fescue — and being able to get a cover crop planted that fall — allowed them to feed the least amount of hay throughout the winter of 2016-17 than in any other year in the four-year study.
With fescue, a curse became a blessing. “Grazing fescue as stockpile is an advantage because it retains quality better than anything else, and they won’t eat it any other time of the year,” Dave says.
4. Cover crop variety trials. PFI conducted cover crop variety trials from 2012 through 2017. The research helped reinforce that cereal rye is the king of cover crops. When looking at ground cover in both spring and fall and its ability to overwinter, rye is by far the most reliable, and cheapest, cover crop in Iowa.
After trialing other winter small grains like wheat, triticale, oats and barley — as well as brassicas and legumes like brown mustard, hairy vetch, radish and turnips — cereal rye took the prize as the most reliable. A host of cooperators conducted this project over the years.
5. Cereal rye cover crop termination date ahead of soybeans, 2016 update. Jeremy Gustafson of Boone and Jack Boyer of Reinbeck looked at how late they could wait to terminate a cereal rye cover crop ahead of soybeans to get the most possible biomass growth for weed control. With an early termination date and a late termination date, they looked at biomass growth at each termination date and yield in those plots.
There was not an instance of any statistically significant change in yield in either the early or late termination plots. However, terminating later in the spring allowed Gustafson to skip a herbicide pass, reducing his costs and saving him around $50 per acre. The same was true for Boyer in 2015; skipping a herbicide pass saved him about $40 per acre that year.
6. Cover crop termination date ahead of corn. Cover crops ahead of corn can be a tricky situation agronomically, with many farmers skipping cover crops ahead of corn altogether. This project, conducted by Dick Sloan of Rowley, set out to solve some of the difficulty of managing corn after a cover crop by altering termination dates of a cereal rye cover crop. The late-terminated cereal rye did have a slight negative effect on yield, while the stands themselves were unaffected. Sloan was able to produce more than double the biomass in the late termination plots, giving him optimism for potential late rye termination in corn.
“I will continue this practice until we can find a way to achieve similar yields with a later termination," Sloan says. "I’m interested in evaluating alternatives to glyphosate when chemically terminating cover crops to see if there is the same corn yield drag to ‘planting green’ into freshly killed covers.”
7. Nitrogen replacement value of red clover. Extending the rotation to include a small grain offers a unique opportunity to plant nitrogen-fixing legumes like red clover. The options are limited and less effective when planting a legume in the fall after a corn or soybean harvest.
Cooperator Tim Sieren of Keota grows cereal rye for cover crop seed on his farm. In this project, the plots were either interseeded with both cereal rye and red clover, or just cereal rye alone. The rye-clover plots and the rye alone plots were all given a high and low treatments of nitrogen.
The results showed that rye-clover plots receiving 100 pounds N per acre yielded as much as the rye-alone plots receiving 190 pounds N per acre. Sieren was able to reduce his fertilizer bills in the rye-clover plots significantly, showing that farmers who are looking to reduce their reliance on synthetic nitrogen have an opportunity to do so by interseeding clover with a small grain.
8. Comparing soil quality indicators among different farming systems. Spurred by the floods of 2008, this study compared soil quality indicators — stable aggregate content, total soil carbon, total soil nitrogen, pH and bulk density — at eight farms with different kinds of farming operations to see how each system measured up. This research shows that different management practices have a clear effect on soil quality indicators, especially having livestock on the land.
9. Horticulture variety trials. Comparing horticulture crop varieties helps narrow down what variety will work on-farm in Iowa. Choosing a variety can be a daunting task when there are so many to choose from. At data.practicalfarmers.org, farmers can compare yield and other production data of different vegetable crop varieties.
10. Horticulture enterprise budgets. Is growing this crop worth it? That's the question enterprise budgets attempt to answer for fruit and vegetable farmers. More information is at PFI.
Tetrick is the digital media coordinator for Practical Farmers of Iowa.