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

How Drought Affects Soil Health

Dr. Mahdi Al-Kaisi, professor of agronomy and Iowa State University Extension and Outreach soil and water specialist, published a great article on the impacts of drought on soil health and management practices that can help reduce drought effects.

Drought conditions during most of the growing season in Iowa can have a profound impact on soil heath, just as when we have extreme wet conditions. The effect of drought can be noticed very clearly on crop performance when the lack of water availability is severe. This water stress can affect soil chemical, physical, and biological activities that are essential for plant and soil health.

One of the obvious effects of drought on soil health is the lack of nutrient uptake by crops, as water is the major medium for moving nutrients into plants as a result of water uptake. The increase in soil temperature associated with lack of soil moisture has an impact on microbial activities and nutrient processing, both of which are important for plant use for biomass and grain production. Microbial activities in soil generally are controlled by soil moisture and temperature. The departure from the optimum ranges of soil moisture (water field capacity) and soil temperature (approximately 76-86o F), which varies for different microbial communities in soil, can alter microbial activity. Changes in soil temperature during drought conditions can affect soil organic matter (SOM) decomposition and increase the release of carbon dioxide. Also, during this process additional mineral N, mostly in the form of nitrate, will be released in the soil system. This change in soil environment affects the stability of SOM and subsequently, affects the soil biological system.

The most profound effect that can be experienced in cropland is the excess release of nitrate which may not be utilized by crops due to the lack of moisture available for the plant to uptake nutrients. This shift in biological and chemical processes during the growing season influences many other relationships that are essential for crop performance, quantitatively and qualitatively, by changing activities that are important to nutrient cycling such as, enzymatic activities, change in soil chemicals concentrations, etc.

Management practices to reduce drought effects
In order to moderate future drought event’s effect on soil health, several practices can be valuable to enhance soil health by improving soil physical, chemical, and biological properties:

  1. Crop residue: crop residue can provide important benefits like improving soil moisture with an increase in soil water infiltration during and off-season as well as increase recharge of the sub-soil profile. The other benefit of residue is the moderation of soil temperature, where crop residue acts as an insulation layer by increasing soil surface reflectance to sun radiation (i.e., change in Albedo, the ratio of the light reflected by surface to that received by it, where residue color is lighter than soil surface). These benefits of crop residue have direct impacts on soil biological and chemical properties by reducing soil temperature and the slowdown of organic matter mineralization. The increase in soil organic matter can increase soil water storage capacity (Fig. 1). The other benefit of moisture conservation and its availability to crops during drought periods is the increase of utilization of nutrients and reduction of nutrient concentration in soil and loss during off-season rain events.
  2. Cover crops: cover crops have many benefits that are critical, especially during drought conditions. The way that cover crops provide such benefits during drought conditions is based on the cumulative effects of cover crops during previous seasons, where they promote better soil biological and physical conditions. It is well documented that cover crops increased soil water infiltration and recharge of the soil profile by improving soil aggregate stability and soil porosity. Furthermore, cover crops contribute to the increase of the soil organic matter pool, which is essential for building soil health.
  3. Balanced crop rotation: crop rotation and diversity of crops within one year or over several years is one of the most important practices that enhance soil health and mitigate drought conditions during the growing season. The diversity of crops on the land can provide a rich soil environment for a healthy and diverse biological system. The inclusion of different crops such corn, soybean, alfalfa, small grain, etc., provides diversity of root systems that promote a wide range of microbial community, therefore enhancing soil nutrient and organic matter pools as compared to a mono-cropping system (i.e., continuous corn).

These practices, in addition to organic amendments, are important in mitigating unexpected drought conditions in the long-term. These practices, along with minimum or no-tillage, can reduce the prolonged impact of drought events by increasing soil resiliency. The degree at which soils in Iowa and the Midwest have absorbed the dramatic impact of drought events was due to the rich soil organic matter content. Factors which contributed to that are the temperate climate and vegetation base (i.e., prairie), which encourage greater organic matter accumulation. This unique soil quality provides high water storage capacity that sustains crop production. So, to sustain such soil quality, we need to maintain it through the implementation of soil health principles by adopting conservation systems.

figure_1_Al-Kaisi drought article 8-23-2017

The article was published by Integrated Crop Management News on August 23, 2017.

Liz Juchems

Iowa’s Future Begins with Healthy Soils

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.

The quality of Iowa’s soils make this a unique place. How we manage Iowa’s agricultural soils affects just about everything else here. From increasing wildlife to improved water quality to sustainable economic development, our future begins with healthy soils.

Janke-PheasantWildlife – Over 97% of Iowa’s land is privately owned, and a vast majority is a part of farms. Most Iowa wildlife spends some or all of their lives on farms.

The same practices that are good for Iowa soils – no-till farming, cover crops, buffer strips, diverse native plant seeded areas, waterways, diverse crop rotations, well-managed pastures – are good for wildlife. The practices provide cover, food and travel corridors. They protect water sources on which wildlife depends. Practices that protect and build soils are good for wildlife too.

Water Quality – Water bodies reflect the condition of their watersheds. Eroding fields deliver sediment and nutrients to streams and lakes. Soils protected from erosion keep that soil and associated nutrients in fields where they belong.

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Fields protected by cover crops or other vegetation growing throughout the growing season retain nutrients in the root zone that would otherwise find their way into streams or ground water. Practices that protect and build soils are good for water quality

Economic Development – Over one-third of the largest 100 food manufacturers have Iowa operations. These companies are located in Iowa because the commodities they depend on are produced here.

HC-SoilStatistics from 2014 showed that agriculture and related industries contributed $31.6 billion to the Iowa economy and was responsible for 122,764 jobs. They also showed that 37 of Iowa’s counties derived at least one half of their economic output from agriculture and related industries.

The foundation of all of this economic activity, now and into the future, is Iowa’s productive soil.

No matter what issue you care about, you need to be interested in protecting and building Iowa’s soils.

Marty Adkins

Who Owns Any Creek?

“Who owns Cross Creek?”

That is a line from one of my favorite films, Cross Creek. Released in 1983, the film is based on a memoir of the same title by Marjorie Kinnan Rawlings, the author of the classic children’s book The Yearling. The film is about her life as owner of an orange grove in Florida and all the local residents of “the creek.”

“Who owns Cross Creek?”

This line popped into my head when I was talking to Ann about our winter workshops. It was clear from the brainstorming activity that many of the farmers and landowners were more knowledgeable and caring about questions concerning soil health than water quality.

When I pointed that out to Ann, she said, “Soil health happens on the land they own and they directly benefit from it. It’s personal. Water is a part of the common good and is less tangible.”

The common good is often a hard sell economically. No one owns the water. So no one is really responsible. Or everyone is responsible?

Let’s face it: when it comes to water quality, we have been slipping in through the back door, so to speak. As Marty Adkins points out in his previous blog post (Reducing Nutrient Losses While Building Iowa’s Soils and Economy), generally the practices that improve soil health also improve water quality.

That’s true. Cover crops are a good example. They are good for soil health, especially where land is highly erodible or degraded. On the water quality side, they play a major role in reducing both phosphorus and nitrogen loss. It is difficult to show a direct return on investment with cover crops in terms of soil health, and it could cost billions of dollars annually to implement the 12 million acres of cover crops needed every year to improve water quality (The Nutrient Reduction Strategy: Creating A More Resilient Iowa). That kind of investment is going to require a seismic change in attitudes toward water quality if it is going to happen.

In his 2012 book, Navigating Environmental Attitudes, social psychologist Thomas Heberlein argues that the way to change attitudes is by changing social norms. Norms are different than attitudes because they are tied directly to behavior, whereas attitudes are based on values and beliefs. In order for norms to change behavior, they must be focused on and activated by how society shapes what we do—i.e., what shapes the status quo. Norms influencing environmental behaviors do change, but it takes years (decades) for norms to emerge, change and strengthen. For norms to function, individuals must feel responsible for their acts.

I am not saying that farmers are deliberating doing wrong—they are following the norms within our current agricultural system. While many farmers could add more conservation practices to their operations, it is the system itself that needs changing. Policies over the last several decades have intensified row crop agriculture and led us to our current water quality and soil erosion challenges. The long-term vision for Iowa must include policies that more readily allow for a diversity of cropping systems and land use (Expand Beyond a Two Crop System, Clean Up Our Water).

Poor water quality is the unintended consequence of agricultural norms that aren’t sustainable. To change this is going to require a seismic change in attitudes.

As we try to implement Iowa’s Nutrient Reduction Strategy, we need to do a better job of helping farmers see where we are, how we got here, and where we need to go. As we heard from one of the speakers at ISU Extension and Outreach’s Agriculture and Natural Resources spring inservice training earlier this year, “Farmers don’t need any help to stay the same.”

In 1983, I couldn’t have imagined how the answer to a question posed at the end of a loved film would become one of the central questions of my career. It has. Who owns Cross Creek? Or any creek?

Here’s how Rawlings responds to her haunting question:

“Who owns Cross Creek?

The red-birds, I think, more than I, for they will have their nests even in the face of delinquent mortgages…It seems to me that the earth may be borrowed, but not bought. It may be used, but not owned. It gives itself in response to love and tending, offers its seasonal flowering and fruiting. But we are tenants and not possessors, lovers, and not masters. Cross Creek belongs to the wind and the rain, to the sun and the season, to the cosmic secrecy of seed, and beyond all to time…”

Jacqueline Comito

 

Working Within Our Current System: A Conservation Chat with Eileen Kladivko

Cover kladivko_creditHost Jacqueline Comito sat down with Dr. Eileen Kladivko, Professor of Agronomy at Purdue University and founding member of the Midwest Cover Crops Council (MCCC), for the most recent episode of the Conservation Chat podcast.

Eileen Kladivko’s chat covered many issues areas that she has studied for decades surrounding soil health, cover crops, earthworms and drainage. To start the chat off, Eileen wanted to make something clear: drainage is essential.

“I like to remind people that we wouldn’t be growing crops at all on some of our most productive lands in the Midwest if we didn’t have tile drainage.”

Tile drainage is essential if we want to farm much of the land that we currently farm – especially in Iowa. While there are benefits to tile drainage, a drawback of the system is the movement of nitrate with water that flows out of tile lines and into the surface water. How can we begin to solve this challenge? Mimic nature and the system that we replaced, Eileen suggested.

We’ve got agriculture, we’ve got lots of human beings here, and we want to be productive. We want to mimic nature where we can, but we’re not going back to pre-settlement conditions. That’s impossible. But let’s see if there are some things we can learn from what the vegetation cycles were, and the hydrology cycles, that can help us with our current system.”

Adding cover crops to our current system is one way to address our nitrate challenge and to mimic the natural vegetation cycle that once existed on the land. Cover crops have seen a steady increase in popularity, and for some farmers, the desire to grow something comes naturally.

A subject that Eileen Kladivko is most passionate about is soil health. Soil health is a popular topic because we want our soil to function to full capacity for crop production, but we understand relatively little about the soil biology that can shape the physical and chemical properties of soil. In recent years, the soil health conversation is shifting to research about soil biology. The downside is that soil health research takes time.

“That’s one of the challenges with the whole soil health thing . . . we’re trying to look at some of the commercial soil health tests that are available right now and see which of those might actually be able to detect changes with time in some of our Indiana sites. It’s quite challenging because the tests are quite variable. Soil health does take time to improve, and sometimes those tests just don’t show it over the short term.”

Without lab tests to show short-term gains in soil health, there is one indicator that can give farmers a short-term pat on the back: earthworms! Earthworm populations are highest in systems with limited tillage and high levels of crop residue. Eileen has spent much of her career counting earthworms.

“I didn’t think that was going to be a long-term commitment of mine,” said Eileen. Decades later, Eileen has developed a foundation for research on the physical and chemical properties of soil as they relate to soil health and good soil biology.

What are your chances of having a high earthworm population within a system that includes tillage? Not likely. Switching to no-till and adding a cover crop will increase your chances to see early signs of soil health and good soil biology before other commercial soil health tests are able to show results. Iowa Learning Farms has seen similar results when counting earthworms under different tillage and cover crop systems here in Iowa.

Listen to the full Conservation Chat episode! If you’re on the go, take the Conservation Chat podcast with you – find it on iTunes or search for “Conservation Chat” on the podcast app of your choice!

Julie Whitson

Expand Beyond a Two Crop System, Clean Up Our Water

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Seth hosted a 3rd grade field trip to his farm on May 11, 2016 and invited us to visit too!

Earlier today Iowa Learning Farms farmer partner, Seth Watkins, was featured in the Des Moines Register Editorial: To clean up our water, go ‘nuts’ like this Iowa famer. Seth has shifted away from a two crop (corn/soybean) rotation on his family farm near Clarinda.  He still grows corn, but has also added oats, alfalfa, and cover crops.  Seth also actively raises 600 cows and has converted nearly 400 acres to prairie, ponds, and other wildlife areas. As a result of this diversification, he has seen better financial returns while improving soil health and water quality.

Be sure to also take a listen to Episode 20 of our Conservation Chat to hear first hand as Seth shares his whole farm approach to conservation.

Seth is no stranger to trying something new.  He agreed to be interviewed by our Conservation Pack for a video series produced by Water Rocks!  It continues to be one of our most viewed videos and is a sneak peak into Seth’s farm and management choices.

You don’t miss out on a great read and fun video as you head into the weekend!

-Liz Juchems