The Practical Blog
Practical Farmers' blog is a place where staff share news, updates, photos, reflections and other musings on our work and members in a more informal setting.
Cover crop termination and cash crop planting in the spring is the most important aspect of cover crop management to ensure good yields. So this spring we’ve scheduled two shared learning calls where experienced cover crop farmers share their “spring cover crop management playbook.” On February 16, Wayne Fredericks, a corn and soybean farmer in Mitchell County laid out his spring plans for us putting emphasis on the importance of planter set up for planting both corn and soybeans into higher residue field conditions created by the cover crop.
“Last fall was the first fall that we seeded 100% cereal rye before corn and soybeans,” Wayne began. “Our first experience with cover crops was fall of 2012, and we did that in strip trials because we saw the need to gather input and research on what cover crops were doing.” Wayne, who was a member of the Iowa Soybean Association Board at that time, used the knowledge he gained in these strip trials to design his finely tuned spring management strategy to maximize benefits from the cover crop and deal with the unique scenarios preceding corn and soybean planting. Wayne’s talk focused on terminating cereal rye in the spring, fertilizer adjustments for corn planted after rye and planter settings for corn and soybeans.
Cover Crop Termination
Before soybeans, Wayne maximizes biomass growth and weed control from his cover crop by “planting green” into living rye for the last three years. He says, “when you include your pre-emerge chemicals with the roundup it takes a higher rate to ensure adequate control.” On his farm they combine the cover crop burn down herbicides with their pre-emergence plan just before soybean planting, including 44 oz. of WeatherMAX® + AMS, 3 pints of Harness®, 5 oz. of Sencor® and generic capture. Continue reading
By Meghan Filbert, Alisha Bower and Nick Ohde
Numerous studies show that continuous living cover – whether it’s perennial pasture, diversified crop rotation with small grains and hay, or cover crops in a corn and soybean system – benefit many species of wildlife, from birds – whether they are hunted or non-hunted species – to insects to fish. Here are a few that we’ve come across as we seek to use peer-reviewed research to inform our thinking about keeping roots in the ground year round.
Small grains are a unique crop in the Midwestern system because they are harvested early – around July – leaving the field open for different field operations and cover crops. This longer window makes it possible to grow a legume cover crop that can synthesize nitrogen and offset purchased fertilizer costs for the following crop in the rotation. But farmers don’t have to wait until August to seed their legume, on our February small grains shared learning call we welcomed Keota farmer Tim Sieren and USDA Ag Research Station technician Keith Kohler to discuss frost seeding legumes, an alternative to waiting until after small grain harvest to establish the cover crop.
“The name ‘frost’ seeding is actually a misnomer,” Keith begins. “It’s really a ‘freeze thaw’ seeding where you want the seed out there as the season warms up.” In early spring as the days begin bouncing back and forth between freezing and warmer temperatures, the ground contracts and expands with the changes, working a seed laying on the soil into the ground. So, if you get a small sized legume seed out there at the right time this natural cycle will do the work of planting it for you. It’s the ideal method for planting clover or alfalfa into an established winter small grain like rye or winter wheat so that the crop isn’t disturbed and can be used ahead of spring small grain planting too. Continue reading
Have you ever heard of a shared learning call? Probably not, unless you’ve been participating in our small grains monthly calls for the past year. They’ve worked so well there that we’ve decided to try out the format for other topics. A “shared learning call” is essentially a conference call, where you dial into a conference line with many others and listen as a farmer shares their practices for about 15-20 minutes and then we open the floor for questions and discussion for the rest of the hour. All you need is a phone!
Our first cover crop shared learning call will be on February 16 from 12-1 p.m. when Mitchell county farmer Wayne Fredericks will share his strategy for managing cover crops and planting into cover crop residue on heavy soils. Fredericks has been no-tilling soybeans for 20 years and has been planting cover crops, mainly cereal rye, since 2011. Here’s a sneak peak of his tips on planter set up for cover crop residue that he’ll share on the 16th:
“Watch your depth if you’re planting into high residue. You want to plant a little bit deeper,” he says. Fredericks sets his planter a quarter-inch deeper than he normally would on his John Deere 1790 which has 24 units on 15-inch rows. He also runs 400-pounds of down pressure per unit when planting into heavy rye residue. “Having the ability to apply the necessary down pressure is key.” If this is your first time planting soybeans into rye, you might want to plant into knee-high growth instead of waiting until it gets to almost three feet high. But, ultimately, “Termination timing isn’t as critical on soybeans as on corn,” he says. “I’ve planted soybeans into cereal rye as high as this table (34 inches).”
- Dial 641-715-3620
- Enter passcode 357330# when prompted
- Put your phone on mute to avoid feedback during presentation and unless speaking in the Q & A
Be sure to your calendars for these additional upcoming shared learning calls:
- Friday, March 2 Noon – 1 p.m. Shared Learning Call on Marketing Small Grains to Breweries and Distilleries
- Friday, March 16 Noon – 1 p.m. Steve Berger of Wellman Shared Learning Call on Cover crops for corn & soybeans: planter setup, nitrogen for corn, termination reminders
“We started planting cereal rye because it was easy to calve in. Now, most all of our covers are grazed as a way to justify the costs,” said Mark Schleisman, of Lake City. Cover crops that are grazed have value, but how much value? A three-year PFI research project, initiated in 2015, helped quantify this value by putting a price tag on the forage produced by cover crops. For three cow-calf producers in northwest Iowa, the practice of grazing cover crops, combined with cost-share funding, provides positive economic returns within the same year the cover crops were planted.
Wesley Degner, of Lytton; Bill Frederick, of Jefferson; and Mark Schleisman seeded cover crops of their choosing with the intention of grazing the forage produced. Farmers kept grazing records in order estimate the amount of dry matter cattle received from the cover crop. This dry matter was then valued at $80 per ton – a conservative value considering that hay is currently selling for $130 per ton.
All revenues and costs were then considered in order to complete an economic analysis. Read the full report here: Economic Impact of Grazing Cover Crops in Cow-Calf Operations
The Trial Was Conducted By:
- Planting cover crops for the purpose of grazing with cows and calves
- Sampling biomass the day cattle were turned out to graze cover crops in the fall
- Tracking all expenses and keeping grazing records
- Plugging numbers into a economic spreadsheet tool developed by Iowa State University
Across the three farms, the value of cover crop forage ranged from $28 to $61 per acre, before costs were removed. Costs included cover crop establishment and termination, labor, fence and water. In some cases, costs exceeded forage value, which highlighted the importance of planting cover crops early and waiting to graze until there is plenty of growth available. In the cases where costs exceeded value, cost-share payments, ranging from $11 to $41 per acre, helped keep farmers in the black.
Total net economic gain ranged from $2 to $60 per acre, a variance that can be attributed to the farmers’ different levels of experience with cover crops and their understanding of issues related to cover crop planting and grazing management. Wesley had never planted or grazed cover crops before this project. “Now that I’ve had a bit more experience with cover crops, I planted an additional 208 acres in 2017,” he says.”I grazed them from November to early January and plan on getting spring grazing out of these acres too. I’m still learning, but I think grazing both in the fall and spring will help me remain profitable.”
To see the full economic impact analysis for each farm, read the full report here: Economic Impact of Grazing Cover Crops in Cow-Calf Operations. This project was supported by the Iowa Department of Agriculture and Land Stewardship.
Two years of monitoring birds on a central Iowa farm has shown that rotationally grazed pastures support threatened bird species. Properly managed pastures, grazed by a herd of grass-fed cattle, created a desirable habitat for grassland birds, which were attracted the pasture’s mix of short and tall vegetation. Some bird species, such as the bobolink and grasshopper sparrow, seemed to prefer these pastures over a nearby prairie conservation area.
Since 2016, farmer Bruce Carney of Maxwell, Iowa has been working with researchers from Drake University to conduct bird counts to better determine the effects of grazing on bird conservation.
Read the full report here: Monitoring Birds in Rotationally Grazed Pasture, 2017 Update
The Trial Was Conducted By:
- Taking weekly bird counts between May and September in 2016 and 2017
- Counting birds in three habitat types; restored prairie, perennial pasture and perennial + annual pasture
- Recording all bird sightings and bird calls in 10 minute intervals
In both 2016 and 2017, there were significantly more birds counted in Bruce’s pastures than in the nearby prairie. “Grazed areas are much more favorable for bobolinks,” said Keith Summerville, Environmental Science professor at Drake University. Bobolinks are ground-nesting birds and prefer grazed grassland over tall and dense vegetation. Some farmers regard bobolinks as an indicator species for a healthy ecosystem.
Two years of data shows that a properly managed, pasture-based grazing operation can provide habitat for a diverse set of birds and support large bird populations. “I learned that you don’t have to have thousands of acres to conserve wildlife. At first, I assumed the prairie would have more birds than my farm, but it really comes down to management. Smaller parcels of land, managed properly, can create favorable habitats and support birds,” stated Bruce.
For more details on this trial, read the full report here: Monitoring Birds in Rotationally Grazed Pasture, 2017 Update. This project was supported by the National Fish and Wildlife Foundation and Drake University.
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.
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.
Aboveground biomass of the cover crop mixes was sampled the day before termination on May 27 at Gustafson’s and amounted to 1,537 lb/ac. Teachout did not collect biomass samples but reported that the mix in Field 1 was 6-10 in. tall at termination on May 19 and the oats+barley in Field 2 was 8-10 in. tall at termination on May 19. He also noted far less weed growth in the cover crop strips compared to the no-cover strips in both fields (weed biomass or weed counts were not collected, though).
Soybean yields at Gustafson’s (one field) and Teachout’s (two fields) are shown in the table below. In all three fields, the spring-seeded cover crop had no affect on soybean yield compared to no-cover crop.
Because they saw no reduction in yield, both farmers are considering using this practice in the future. “I will use this practice [in the future] in the case of no fall seeded cover crops,” Teachout said. “The next steps are to see if spring-seeded covers can be grown with early planted soybeans as a beneficial nurse crop.”
For more details on this trial, read the full report here: Spring-Seeded Cover Crops Ahead of Soybeans.
This project was supported by the Walton Family Foundation.
Are you growing rye or winter wheat for grain or seed this year? What’s the plan after your harvest? If you’re looking to add nitrogen for a 2019 corn crop, now might be the time to think about frost seeding red clover into that rye or wheat in late February.
The research is clear: if you can find a market for small grains, adding a third crop to your rotation yields economic, agronomic and environmental benefits. Iowa State University and Dr. Matt Liebman’s research near Boone shows that corn and especially soybeans yield better when grown in rotation, soybeans have less incidences of disease, soil health metrics improve, erosion decreases and water quality improves – all this with equal returns to land and management.
You can learn more about Matt Liebman’s research and many of the benefits of small grains production from other farmers in this video from our Rotationally Raised series:
You can also check out a farminar Matt hosted a couple years ago with Dick Sloan and his presentation from the 2016 small grains short course at the PFI Annual Conference.
In Iowa, most of this research and most farmers’ experience has been with adding oats and/or hay to their rotation. But now, with more and more people planting cover crops – and most of them planting cereal rye, more and more people have been raising it for seed. Saving a few dollars on cover crop seed is great, but the real opportunity comes after rye harvest when you can grow another crop.
Many people in that boat are planting multi-species cover crop mixes, and for farmers with cattle, that’s tough to beat. A balanced grazing ration that likely includes a few protein sources and plenty of sorghum-sudan grass is a great way to save money on hay costs later in the year, and maybe be able to rest some permanent pastures in the fall so they’ll produce better next year. Learn more about what farmers with livestock are planting after small grains harvest in this episode of Rotationally Raised:
Growing Your Own Nitrogen
But for row crop farmers, harvesting small grains during the summer presents a perfect opportunity to grow some nitrogen. It’s something organic farmers have been doing for years to augment manure as a nitrogen source. However, most organic farmers either have hay in their rotation or grow oats, a spring small grain, and seed red clover with the legume/forage hopper of their drill at oat planting time.
But what about seeding clover into an already established winter small grain, like rye or winter wheat? Can you do it? “It’s always worked for us,” say Doug Alert and Margaret Smith, who own and operate Ash Grove Farm near Hampton in north-central Iowa. They’ve been frost seeding red clover into winter small grains for about the past 10 years, and have always managed to get a stand of clover established.
And, because they’re organic, clover establishment is crucial: “We can’t afford to have a failure because that’s a major source of nitrogen for the corn crop,” Doug says. Iowa State University research has shown that farmers can expect a nitrogen credit anywhere from 75 – 100 lb / acre.
Benefits of Red Clover
Dr. Bill Deen studies cropping systems and nitrogen management at Guelph University in Ontario, where winter wheat is a more predominant component of cover crop rotations. Many of his findings stem from a long-term crop rotation study started in 1980 that, among other configurations, includes a rotation with red clover frost-seeded into winter wheat ahead of corn.
“What’s remarkable about red clover is you get the N credit while simultaneously increasing corn yields,” he says – in other words, the clover provides additional benefits that increase yields above and beyond its contribution to nitrogen, a phenomena known as the rotation effect. “We’re not quite sure what the mechanisms are. Certainly it does add N to the system,” he says, “but it also seems to improve the use of N by the corn crop,” Deen suspects that it may have something do with how clover affects the soil.
The other advantage of red clover over other cover crops is that the nitrogen release pattern works well ahead of corn. “It seems to have an effect on soil nitrate that is very favorable when you look at the pattern of demand by corn,” he says. Radishes, for example, may release the nitrogen too early, and rye might hold onto it for too long. “Red clover is the most consistent supplier of nitrogen,” he says.
Red Clover in Practice
Two challenges to working red clover into a winter small grain system are planting and terminating. For planting, Dr. Deen agrees with Doug and Margaret – as soon as the snow is off, but the ground is still frozen, it’s time to frost seed. “Going from impassable snow to mud is often a very short time frame,” Doug says, “So you have to be ready to go when you hit that window.”
- Ideal frost seeding conditions;
- Selecting clover varieties for frost seeding and your management goals;
- And which legumes should be planted instead for best effect.
Frost Seeding Red Clover in Iowa
Actually doing the seeding isn’t that tough. Iowa State recommends broadcasting 10-15 lbs/ac onto frozen ground and the seeding method is likely going to be dictated by what equipment you have available. “I like that you don’t have to have a top of the line system for it to work,” Margaret says. When they first started seeding red clover into rye, Doug used a 3-point mounted fertilizer spinner, and that worked okay – he could cover a 20-25 ft. swath. Later, he switched to a grain drill and just used it as a drop seeder, but that was only 15 feet of width, and trying to cover a lot of acres quickly is tough on a drill.
So last year, he built a toolbar specifically for seeding red clover – it adds seeding capacity, and it also links into his auto-steer, which is important because he’s doing a lot of this seeding at night, when the ground is nice and hard. His setup – shown in the photo – is a Gandy Orbit-Air seed hopper mounted on a used sprayer boom with a hydraulic metering system.
With this setup, he can seed 40 acres between fills and because he can drive 7-8 mph he can cover around 20 ac/hr. “This is all very important because of the small time window,” he says.
And, some years, the window is too short, and they don’t get a chance to frost seed. But they still seed it, even if it’s a little late, and haven’t had a failure so far. And that’s not necessarily intuitive. “Clover’s low-light tolerance is phenomenal,” says Margaret, “To me, it looks like it should never survive,” when looking at the thick blanket of rye that soon covers the clover, but adds that they’ve never had a problem getting a stand of clover established.
Red Clover Termination Before Corn
Once it’s seeded, there’s little management of the clover between seeding time and termination prior to corn planting. And because Doug and Margaret are organic, herbicide termination is not an option. Instead, they have traditionally plowed the clover as soon as they could in the spring; likely right after oat planting is done. They’ve been debating whether the plow is the right option for termination – or whether a lighter tillage pass would be sufficient – and whether spring or the previous fall is the appropriate time to terminate.
For conventional farmers, light tillage and plowing are still options, but termination with herbicide can also do the job. Penn State University Extension – where red clover is more commonly used as a cover crop – has some good guidelines. They recommend the following: “An excellent herbicide program to terminate a red clover stand prior to planting corn is one pint of 2,4-D LVE and one pint of dicamba (Banvel or Clarity). Apply 2,4 D and/or dicamba 7 to 14 days prior to or 3 to 5 days after corn planting if corn seeds are planted at least 1.5 inches deep. Do not plant soybeans after dicamba application. Applying 1 to 2 pounds per acre of atrazine will help provide additional control of the red clover. Glyphosate or paraquat alone are not recommended to kill a legume such as red clover.”
Red Clover Green Manure Resources
Practical Farmers of Iowa continues to conduct on-farm trials on the usage of red clover as a cover crop. PFI members have conducted research on many of the topics discussed in this article, from comparing red clover to mid-summer-planted mixes, to the nitrogen value of red clover, to interseeding clover into winter rye, and much more. To find the results of these trials, check out practicalfarmers.org/research-reports and search for “red clover.”
Here are a few:
Iowa State University also has a good production guide on using clover with winter small grains: “Intercropping Winter Cereal Grains and Red Clover” (PM 2025).
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.
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
Aboveground biomass of the cover crop mixes was not sampled but photographic evidence shows that cover crops persisted beneath the corn canopy into early fall at both farms.
Corn yields at Boyer’s were affected by the hybrid (horizontal leaf architecture vs. vertical leaf architecture) and the interseeding. See figure below.
At Jeremy Gustafson’s, corn yields were not affected by hybrid or planting population. All strips were interseeded. See figure below.
“The seed germinated well,” Gustafson said, seeing mostly cowpeas by mid-September. “Not much made it into fall, though. Leaf architecture didn’t seem to matter and lack of rain really played havoc with this trial.”
“This technique requires more testing before wide spread adoption,” Boyer said. “I need to understand what caused the yield hit. The cover crop species I interseeded worked with both corn varieties, so I will probably try another interseeding with just one variety.”
For more details on this trial, read the full report: Corn Leaf Architecture for Interseeded Cover Crops.
This project was supported by the Walton Family Foundation.
It’s hard to pick just one favorite part of the PFI conference, but I think mine is our potluck and this year we have a special treat – a whole roast pig from one of our members! Please join us Friday January 19 from 7-11 pm for a shared meal hosted by Ty and Bobbie Gustafson of Story City Locker and Donna Prizgintas and Lonna Nachtigal of the DonnaLonna Kitchen Show. Practical Farmers will provide a main dish, coffee, water and tableware. Please bring a side dish and beverage to share.
Potluck is held at CMPI Event Center (2321 North Loop Dr.) in Ames. Friday January 19, 7:00-11:00 pm.
- A whole roast pig from Crooked Gap Farm, roasted by Story City Locker;
- Buns from Madrid Bakery;
- Salad greens from Lee’s Greens;
- Beans from PFI member Darren Fehr;
- Coffee and water;
Don’t want to keep food cold or warm all day? You may drop food off at Scheman when you arrive for the conference and we will transport it for you! Items can be dropped off on a designated table on the ground floor at Scheman. We will transport food from there until 5 pm 1/20/17. We can plug in crock pots and refrigerate dishes.
Need to pick something up last-minute? Visit one of these local establishments: