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.

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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!

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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.”
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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.

Can cereal rye cover crops suppress weeds?

A question recently arrived in my email inbox: What is the potential for weed suppression when using cereal rye cover crops?

To help answer the question, I reached out to Dr. Bob Hartzler, ISU Extension Weed Specialist and Professor of Agronomy, and Meaghan Anderson, ISU Extension Field Agronomist.


There is pretty good evidence that a thick, consistent Slide1stand of cereal rye can effectively suppress winter annual weeds.  In soybeans, rye with even cover and a lot of biomass (>4000 lb/ac) may provide some early season weed suppression, but generally the weeds will begin to emerge as the cereal rye breaks down.

Ann and I saw this first hand yesterday (photos below) when visiting our long term rye site in Page County to collection biomass samples. In the cereal rye strips only one or two field pennycress plants were found. However, in the neighboring strips without cover crops, the winter annual weed was thriving.

No evidence yet that cereal rye will help control perennial weeds, but it may help Slide2suppress perennial weeds germinating from seed or perennial rootstalks like dandelion, Canada thistle, field horsetail, etc.  Perennials normally develop from established root structures with a lot more energy reserves, so they are going to be tolerant of the competition from the cover crop.  If repeatedly used, cover crops could provide some suppression of things like dandelion and such.

Whether or not it provides some suppression or control of  resistant weeds would depend on whether those weeds fall into the categories listed above (early-season weeds or winter annuals) and whether the cover crop stand is consistent.

To keep up to date on weed issues, follow Dr. Hartzler on Twitter @ISUWeeds!

Liz Juchems

Now Available! Evaluating Cover Crop Seeding Techniques Publication

Seeding Tech LocationsThe Iowa Cover Crop Working Group (ICCWG) has wrapped up a two-year study evaluating planting techniques for the successful establishment of cover crop mixtures and single species in Iowa. We are grateful to our partners: Hagie Manufacturing Company, famer partner Tim Smith, and Iowa State University Northern Research and Demonstration Farm.

Replicated cover crop strips were established in fall of 2014 and 2015 to compare three different seeding techniques:

Evaluation was completed through fall and spring biomass collection and crop yield. A no cover crop plot was included in the replications as a yield comparison check strip.

The mixtures species were selected based on the upcoming crop and their winter hardiness. Because the species seeds are different sizes, a goal of one million seeds per acre was used for seeding calibration to provide a fair comparison between treatments.

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Oats and rye win the day

Results show that earlier seeding with the high clearance interseeder resulted in more cover crop biomass, both fall and spring, than the later seeding with a drill. For Iowa, oats and rye work better than any other species tested at this time. The single species (oats and rye) resulted in more total biomass than the mixtures providing better soil erosion protection. Oats and rye were also the predominant species in the mixtures, accounting for the majority of the biomass.

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There are no statistical differences in corn or soybean yields across the different cover crop treatments and no cover check plots. This yield neutral response following a cover crop is consistent with a long term ICCWG cereal rye cover crop project now entering its ninth year.

The publication is now available online and at upcoming ILF field days.

This research project was made possible with a State Conservation Innovation Grant through the Iowa Natural Resource Conservation Service.

The ICCWG includes core members from: Iowa Learning Farms, Practical Farmers of Iowa, Iowa State University Extension and Outreach, USDA-Agricultural Research Service, Leopold Center for Sustainable Agriculture, Iowa Department of Agriculture and Land Stewardship.

Reducing Nutrient Losses While Building Iowa’s Soils and Economy

Today’s guest post is by Marty Adkins, Assistant State Conservationist for Iowa Natural Resources Conservation Service (NRCS), a member of the Iowa Learning Farms Steering Committee.

Iowa’s soils are globally precious and unique. These soils are the cornerstone of a vibrant and productive farming sector and make Iowa’s overall economy strong.  Protecting and building the productive capacity of Iowa’s soils is essential to Iowa’s future.  Happily, many of the same practices that help protect and build soils also have a positive impact on water quality.  This is especially true of cover crops, crop rotations that include small grains and forages, and no-tillage and strip-tillage planting.

Marty Adkins and his other passion in life; playing the ukulele.

The widespread adoption of cover crops will require increased availability of seed and seeding equipment.  There are new business opportunities related to the growing, cleaning, transportation, sales and custom planting of cover crop seed.  Iowa’s farm machinery industry can continue to design, build, sell and service equipment needed for cover crop seeding and management, and increased adoption of no-till and strip-till.

There are other farm business opportunities to consider when it comes to conservation farming practices.  Cover crops and extended rotations could provide more grazing for more livestock in more places, with more small-town businesses selling all needed goods and services to livestock farms.

In addition to increased economic activity in the farm and industrial sectors, there are other economic benefits to be gained from conservation practices.  An Iowa countryside that is green nearly all year-round, with the land covered and protected, would be a more attractive landscape for Iowa residents, and could attract visitors and new entrepreneurs.

Economic research shows that cleaner streams and lakes result in increased recreational opportunities (swimming, canoeing, boating, and fishing) and more tourism to towns and cities associated with these amenities.  More dollars stay in Iowa when Iowans vacation and recreate within the state.

The environmental benefits associated with better soil management are well documented.  But improved soil management can also contribute to Iowa’s economic well-being, now and long into the future.

~Marty Adkins

Cover crop researcher Tom Kaspar receives Spencer Award

Congratulations to our friend and collaborator, Dr. Tom Kaspar, on receiving the Spencer Award for Sustainable Agriculture yesterday!

Long regarded as the grandfather of cover crops here in the state of Iowa, USDA-ARS plant physiologist Tom Kaspar is certainly one of the leading voices on cover crops across the Midwest.  He was one of the “founding fathers” of the Midwest Cover Crops Council, and his collaborative work over the years has investigated and documented the benefits and challenges of cover crops in corn and soybean cropping systems, ranging from impacts on water quality, soil health, nutrient cycling, and more.

We are grateful to Tom for serving as a guest speaker at countless Iowa Learning Farms field days and workshops over the years, sharing his findings with farmers, landowners, and other ag partners across the state. We are also grateful for his efforts in guiding the work of the Iowa Cover Crop Working Group, including our long-term on-farm rye study and our study of earthworms and cover crops.

Kaspar has amassed years of experience investigating not only soil health and cover crops, but also connections with no till, minimum tillage, climatic variations, disease, pathogens, and more. To hear some great perspectives from the man himself, check out Episode 6 of the Conservation Chat podcast, in which host Jackie Comito talks cover crops with Dr. Tom Kaspar.

Kaspar was also featured in our August 2015 Iowa Learning Farms webinar, presenting on Reaching the Full Potential of Cover Crops in Iowa.  Stay tuned to the blog, as well — we’ll be highlighting some of Kaspar’s cover crop findings here in the next week or so.

In the meantime, congratulations to Tom for an honor that is very well deserved!

Ann Staudt