On-the-Ground Experience with Cover Crops

“What’s building organic matter worth to you?”

For Prairie City, IA farmer Gordon Wassenaar and tenant farmer Will Cannon, it’s worth using no-till and cover crops on every single one of their 1300 acres of cropland.  In a field day hosted by Iowa Learning Farms, Jasper Co. NRCS and SWCD, Wassenaar and Cannon shared their perspectives on cover crops and how they can be very successfully integrated into corn and soybean cropping systems.

Wassenaar, who has farmed for over 50 years, stated that he first got into cover crops for the purpose of protecting the soil from erosion. He started with cereal rye, broadcast seeded from an airplane.

As time has gone on, Wassenaar’s reasons for using cover crops have evolved from simply erosion control, to improving the structure and functioning of the soil — raising soil organic matter, aggregate stability, and water holding capacity. Cannon commented that on top of that, another big benefit is feeding the biodiversity of the soil, like the beneficial mycorrhizal fungi, all while growing a healthy crop.

Timing and seed-soil contact are two big factors with establishing successful cover crop stands, and it’s a balancing act between the two. Aerial broadcast seeding (or interseeding with a high clearance vehicle) allows for a larger window of time for fall growth, while drilling provides greater seed-soil contact. Today, Wassenaar and Cannon have moved to drilling all of their cover crops, ideally getting them in the ground 24 hours or less behind the combine.

When asked about the financial considerations of cover crops, Cannon responded, “We’ve got to be willing to be a little creative and inventive to make it work.”  And they certainly are.

Cannon outlined several approaches they are taking to minimize costs and improve efficiencies in their operation:

  1. Shop around for cover crop seed.
    Compare prices with different cover crop seed houses in order to get the best bang for your buck. Wassenaar and Cannon are even considering growing their own cover crop seed down the road.
  2. Consider your seeding techniques.
    Aerial broadcast seeding and custom planting carry a significant cost.  Cannon explained that they have moved to seeding all of their acres now with a drill, which has provided greater seed-soil contact, and thus improved the seeding efficiency in terms of the number of seeds that actually grow (they’ve subsequently optimized/reduced seeding rates accordingly).  They are also saving dollars through the use of a smaller 120hp tractor and a cover crop drill that was bought used.
  3. There are a lot of good programs out there that can help.
    Take a look at the conservation programs and personnel on the federal, state, and local levels that can help out.

With years of experience implementing conservation practices of no-till and cover crops, Wassenaar reflected on how much the technology advances make conservation readily doable today.

“Back in the day, we plowed because we didn’t have planters that could plant into high residue. The equipment is so good today, that now we can plant into just about any residue.  … With cover crops out there, it’s almost like planting onto a mattress.”

Wassenaar is clearly passionate about conservation, and left field day attendees with the following thoughts:

“I don’t know any other way you can farm and save your soil than with no-till and cover crops.  … I’m convinced that if Iowans take care of their soil, the soil will take care of Iowa.”

Ann Staudt

Reducing Soil Erosion with Cover Crops: New Infographic

Iowa Learning Farms is pleased to announce the release of a new infographic publication titled Reducing Soil Erosion with Rye Cover Crops.

This visually engaging document highlights one of the biggest benefits of cover crops — the ability to significantly reduce soil erosion. Based upon long-term cover crop work conducted by Korucu, Shipitalo, and Kaspar, colleagues at the USDA-ARS National Laboratory for Agriculture and the Environment here in Ames, this study looks specifically at one of Iowa’s most popular cover crops, winter cereal rye.

The USDA-ARS team conducted in-field simulated rainfall studies on plots with and without cereal rye cover crops, and their findings are powerful in terms of quantifying erosion reduction – 68% less sediment in surface runoff water with a rye cover crop. Further, the amount of surface runoff water decreased, while the amount of water infiltrating was found to increase with the cover crop.

This study was conducted in central Iowa, in the heart of the Des Moines Lobe, on land with a 2% slope. Substantial erosion reductions were found here with rye cover crops — consider the benefits of cover crops to reduce erosion on more sloping lands across the state!

The full infographic is available as a free PDF download on the Iowa Learning Farms website. Clicking on the image below will also take you right there.

Ann Staudt

Cover Cropping on the Lobe

Last evening, a group of 40 area farmers, Soil & Water Conservation District commissioners, and a nice delegation of ISU students from the Ag & Biosystems Engineering department gathered up at Gilmore City, Iowa for a conservation field day hosted by Iowa Learning Farms. Located between Humboldt and Pocahontas, in the heart of the Des Moines Lobe, the Gilmore City research site is home to some of the longest running research in the state on nutrient management and drainage water quality. Last evening’s field day focused on conservation practices that could be utilized in-field (emphasis on cover crops) as well as edge-of-field (bioreactors, saturated buffers, and wetlands).

Kicking things off were father-son duo Bob and Jay Lynch, who farm just outside of Gilmore City. The Lynchs have been long-term ridge tillers, and in recent years, have largely transitioned to strip tillage. In addition, they began integrating cover crops into their corn and soybean operation in 2012, and they have continued to increase cover crop usage since then. With five plus years of cover crop experience under their belts, Bob and Jay shared some words of wisdom and lessons learned with field day attendees.

 

Benefits of Cover Crops
Bob and Jay Lynch see soil health as the biggest reason to use cover crops. Bob commented, “To see the real benefits of cover crops, you need to go below the ground surface. I go out in my fields where I had rye, and take a shovel out there – the biologicals in the soil are a big deal. I hope I get an earthworm in EVERY handful of my soil! The cover crop roots give them something to eat for much more of the year. In addition to the earthworms, you have all of the other beneficial microbes, too.”

The “feel” of the soil is improved with cover crops, as well. The Lynchs spoke about cover crops giving their soil “a really nice spongey-ness.” The benefits of soil aggregation are there, too, with a cover crop – Bob referenced that the ground would come apart just like cottage cheese with a rye cover crop!

While the Des Moines Lobe is known for its rich, fertile soils, cool temperatures can pose a challenge. The Lynchs commented that cover crops help to moderate soil temperatures, and those results are consistent with data collected from the research plots at Gilmore City, as well.

The Lynchs have also seen some weed suppression benefits with cover crops – when the rye gets knee high in the spring, they’ve seen its potential for blocking out/reducing the abundance of some competing spring weed species.

 

Fall — Cover Crop Seeding
Aerial application of the rye cover crop has resulted in the best cover crop stand for the Lynchs. They emphasized that fall growth is a function of light availability, so the amount of crop canopy cover will be a big factor with the cover crops starting out.

With adequate moisture, rye cover crops will germinate quickly and begin their fall growth. Here is some emerging rye at the Gilmore City research site, just five days old!

 

Spring – Cover Crop Termination
With rye and other overwintering cover crop species, spring termination is necessary ahead of planting your row crops. The Lynchs prefer to terminate their rye via chemical in the spring. For the greatest effectiveness, Bob and Jay have found success in separating out herbicide application into two passes – even on the same day — applying glyphosate first to begin the rye termination process, then following with the pre-emergence residual herbicide.

While rolling, roller crimping, and tillage are also possibilities for cover crop termination, they require very particular conditions for success, and as Bob puts it, “It you try to till rye, you’re just making it mad … and then it comes back with a vengeance!”

 

Spring – Planting into Cover Crop Residue
When rye is growing ahead of corn, the Lynchs presented two options for termination timing: plant your crop the same day you terminate your rye, OR it needs to be dead for 14 days before planting corn.

With abundant cover crop growth, they emphasized that planter settings should definitely be taken into consideration. When planting soybeans into rye residue, the Lynchs recommend that your soybean seeds be planted using similar settings as if you were planting corn. If you use the same bean setting as you would without cover crops, you run an increased risk of the bean seeds sitting on top of the surface.

 

Management Matters
Bob and Jay concluded, “With cover crops, it all comes down to management. What works with YOUR individual farm?

 

Wetlands in the Spotlight
The evening field day concluded out at a CREP wetland just a few miles from Gilmore City, sited specifically for nitrate removal. It was a stunning end to the field day as the sun dropped lower and lower on the horizon!  The beauty of the wetland and its ability to benefit water quality clearly piqued people’s interest, as the questions and conversations continued even after the sun went down.

Ann Staudt

Exploring whether cover crop mixtures make sense on Iowa farmland

Last week I had the opportunity to attend the Soil and Water Conservation Society’s 72nd Annual Conference in Madison, Wisconsin.  In addition to attending some great sessions, meeting fellow conservationists, and exploring Madison, I participated in the Conservation Innovation Grant Showcase poster exhibition.  On display were early results from our cover crops mixtures project that began in 2013.

NCIGCoverCropsPoster-170721

 Some preliminary observations from the study: 

  • Achieved more biomass from the single species (oats or rye) than mixtures
  • Oats and rye resulted in the majority of biomass from the mixtures
  • Cereal rye was the only species to over-winter consistently
  • Generally lower pore water nitrate concentrations following rye and mixture of rye, radish and rapeseed

As we continue to analyze the data collected, the project indicates:

  • Cereal rye and oats establish readily and provide the most biomass growth when seeded on their own.
  • Cover crops can offer some water quality benefits, reducing nitrate concentration in pore water.
  • Rye and oats provide the best biomass return on seed investment! Single Species are the way to go in Iowa for corn and soybean producers.

Be sure to subscribe to our blog and check back for updates on the project, including analysis on crop yields.

Liz Juchems

 

 

The Nutrient Reduction Strategy: Creating A More Resilient Iowa

Have you ever fallen in love with a new car at the dealership and wanted to take it home until you look at the sticker price? Well, as I travel around Iowa, it seems like folks are pretty enthusiastic about the Iowa Nutrient Reduction Strategy (NRS) until they hear the “sticker price,” i.e. the scale of practice implementation and cost.

NRS Goals_3-24-2017

One example scenario to reach the nitrate-N reduction targets of the Iowa Nutrient Reduction Strategy includes 60% of corn-soybean and continuous corn acres having cover crops (~12.5 million acres), 27% of all agricultural land being treated with a wetland, and 60% of the tile-drained acres being treated with a bioreactor.

For wetlands, it was assumed that each wetland (10 acres of wetland surface area with 35 acres of buffer) treats 1,000 acres of agricultural land, which would result in approximately 7,600 wetlands for this scenario. For bioreactors, it was assumed that each bioreactor treats 50 acres of subsurface-drained land, which would total approximately 120,000 bioreactors in Iowa alone.

See what I mean – quite a sticker price!

BioreactorInstall_HamiltonCo_IA Soy Assn_Christianson_credit

But, while the scale of implementation and costs associated with reaching the NRS goals seem daunting, it is important to recognize the additional benefits that could come from pursuing nutrient reduction such as the economic benefits of cleaner water as well as the employment and labor opportunities to implement the various strategies.

Throughout the Midwest, discussions have begun on resources needed to implement the various state nutrient reduction strategies. While this is encouraging and exciting, most of the discussion has focused on the resources needed to implement the practices. There is very little discussion of the labor needed to successfully scale up the practices.

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I believe that for large-scale implementation of the NRS to be successful, we need to make the necessary investment in people. We need trained individuals that can work with farmers and landowners on implementing these practices. We need them both in the private and public sectors. Developing and delivering programs and classes that can train individuals to promote and assist in NRS practice implementation is crucial if we are going to make significant progress on reaching our nutrient reduction goal. There will be a significant increase in job opportunities for individuals who are trained and willing do this work.

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I firmly believe that if we accelerate the rate of practice implementation, we will see numerous small business opportunities throughout rural Iowa to site, design, and maintain these various practices and provide technical assistance to farmers and landowners.

 

It is a win-win for our state. Yes, it is a big investment, but it could stimulate our economy and make for a more resilient Iowa in every way.

Matt Helmers

Matt Helmers is an Iowa Learning Farms team member and Professor of Agricultural and Biosystems Engineering at Iowa State University. To hear more about implementing Iowa’s Nutrient Reduction Strategy, listen to Matt’s Conservation Chat with ILF Program Director Jacqueline Comito.

Do cover crops reduce phosphorus loss?

Cover crops are proven to reduce nitrate loss and decrease soil erosion on our agricultural landscape, but field scale studies on phosphorus loss are still in their infancy. Drs. Antonio Mallarino, Matt Helmers, Rick Cruse, John Sawyer with Iowa State University and Dan Jaynes with National Laboratory for Agriculture and the Environment have completed two years of a long-term field study and have released their preliminary results.

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The Hermann farm site south of Ames allowed Mallarino’s team to observe the effects of cover crops on phosphorus in the runoff study funded by the Iowa Nutrient Research Center.

The study is located at south of Ames on Iowa State’s Hermann Farm. The study includes replication on 12 areas ranging from one to three acres in a field that tested very high in soil phosphorus and is managed with a corn and soybean rotation. The study compares the use of winter cereal rye cover crops with and without tillage.

After two years, Dr. Mallarino observed:

“It is confirmed that cover crops reduce soil loss with tillage or no-till but mainly with tillage. Results also show that with tillage a cover crop reduces phosphorus loss. But it is not so clear that with no-tillage management a cover crop reduces phosphorus loss,” Mallarino said. “With no-tillage, there seems to be a small reduction in particulate phosphorus loss, but an increase in dissolved phosphorus loss.”
revisedherman-flowing-runoff-6-14-17

Surface runoff at the testing site is evaluated for total solids and several forms of nutrients.

Why the focus on dissolved phosphorus? The Iowa Nutrient Reduction Strategy is a technical, scientific and voluntary approach to reducing the loss of nitrogen and phosphorus to our waterbodies and the Gulf of Mexico that is home of a large hypoxic or dead zone.  Both particulate and dissolved phosphorus are part of the reduction goal, however dissolved phosphorus is responsible for algae blooms and has a visible impact on aquatic ecosystems.

Caution should be taken when drawing conclusions from only two years of data. Environmental factors play a role in nutrient dynamics with surface runoff, and during the two years of the study, major rain events at the test site had been minimal with very low runoff.

“We can’t make a strong conclusion from these two years of data. There needs to additional data collection from this site and better science-based projecting so we can encourage the addition of cover crops for the right reasons,” Mallarino said.

Click here to read the full article and learn more about project.

Questions about the project contact:

Antonio Mallarino, Agronomy, 515-294-6200, apmallar@iastate.edu

 

Liz Juchems

Cover Crops: One Piece of the Puzzle in CLL Project

Cover crops are an important tool for helping keep soil, nitrogen and phosphorus in the field – instead of our water bodies. Because they grow outside the typical corn/soybean growing season, cover crops help reduce soil erosion and take up nutrients that could otherwise leave the field. It is also the most popular practice among our Conservation Learning Lab (CLL) farmer partners.

The CLL project is studying the impact of conservation practices implementation at the watershed scale in Floyd and Story County.  The conservation planning process within the watersheds has yielded cover crop contract enrollment of 675 acres and 1,081 acres, respectively, starting this fall covering 50-68% of the crop acres within the watershed.

Cover_crop_April_Berger_FarmThe farmer partners chose to seed either winter cereal rye and oats.  These grass species are easy to establish, relatively inexpensive and are the leading biomass producers in our cover crop research projects – keeping that soil covered (reducing the loss of phosphorus) and taking up nitrogen.

The Iowa Nutrient Reduction Strategy team reviewed cover crop research results from across Iowa and the Midwest and found that cereal rye and oats reduced nitrogen loss by 31% and 29%, respectively.  Similarly, the reduction of phosphorus when adding cereal rye is about 29%, primarily as a result of reduced soil erosion. According to our RUSLE2 calculations, a cereal rye cover crop added to a no-till system can reduce soil erosion by 30-80% and can be even larger when transitioning from a conservation tillage system.

Be sure to keep checking back as we will be providing updates as the cover crops are seeded this fall!

The project is funded by the Iowa Department of Agriculture and Land Stewardship (IDALS) and the United States Department of Agriculture – Natural Resources Conservation Services (USDA-NRCS) of Iowa.