Blog

May 17 2013

Mustard as a Cover Crop

This article was originally posted on December 14, 2010.

Benefits of Mustard

Mustards are a good cover crop for a variety of reasons.

One of the main benefits is that they have high levels of glucosinolates. According to Cornell University:

The practice of using mustard cover crops to manage soil-borne pathogens is known as biofumigation. Biofumigation is simply the suppression of various soil-borne pests and diseases through naturally occurring compounds. All brassicas such as cabbage, kale, cauliflower, brussel sprouts, broccoli, mustard, and turnips naturally produce glucosinolates, the compounds that make certain brassicas “hot”. Brassicas sold as cover crops have been identified or specifically developed to contain very high levels of these glucosinolates. The higher the levels of glucosinolates present, the better the biofumigant effect. The process works as so: when plant cells are damaged such as by chopping, glucosinolates are released and come in contact with an enzyme (myrosinase). In the presence of water, the reaction produces the natural gas isothiocyanate (ITC). ITC is responsible for the suppressive effects of the practice. ITC is similar to the active ingredient in Metham Sodium or the conventional fumigant Vapam (a.i. Methyl ITC). In addition to the soil biofumigation benefits, brassica cover crops are ideal for adding organic matter to the soil and improving many soil health related characteristics due to the large quantity of “green” or fresh biomass produced and incorporated into the system.

(http://ccesuffolk.org/managing-soil-borne-pathogens-with-mustard-cover-crop)

Take a look at the interview I did with Kim and Matt Davidson from Mighty Mustard™:

If you’re unable to see the video, simply refresh your browser or click on the link below to watch it on YouTube.

Mustard as a cover crop?

Advantages of mustard as a cover crop:

Acts as a natural biofumigant
Generally winterkills (at 26 degrees F)
Easy to kill with herbicides and tillage
Provides alleopathic weed control
Helps “clean up” problem fields where nematodes are a problem
Hinders the germination/survival of ryegrass and other cover crops…may be used to clean up a problem cover crop ryegrass field
New varieties are superior to VNS or wild mustard for nematode or weed control/suppression

Disadvantages

Best to be planted 1-2″ deep
Must be planted as a monoculture
Must be killed or tilled in for a minimum of three weeks before planting a subsequent cash crop
Must have rain or irrigation after tillage/killing to help release glucosinilates
Needs 5-6 weeks growth for best results
Must not be used for animal feed

Visit Mighty Mustard for additional information on mustard as a cover crop.

May 15 2013

Myths Debunked on Cover Crops and Colder Soil Temperatures? – Final Report

Sometimes apparent myths prove to be true and sometimes they prove to be…myths!

In March 2013 I asked my brother Don Robison from Robison Farms to help me figure out how cover crops might effect soil temperatures. We have looked at data in previous posts trying to answer the question “Do Cover Crops that Survive the Winter Keep the Soil Colder in the Spring than Fall-Tilled Soil?”

Now I have asked Don to chart all of his data that he has taken since late March in fall-tilled soil, no-till soil, no-till soil with cover crop annual ryegrass, and a lawn. Don added a test of taking moisture readings as well because “we know” that no-till soils are “always wetter and colder than fall-tilled soils.” At least that is common “knowledge” from many farmers I talk to from Minnesota to Missouri and points eastward.

Don made some comments that I believe are helpful:

The soil type in the lawn is Miami silt loam, while the fields are Crosby silt loam.
The no-till w/o cover crop test had a compaction layer at ~3-9″ deep in this area in our compaction tests we conducted in 2012. Don’s thought is that where he is doing the tests had a compaction layer closer to the 3″ depth (so there is less percolation).
Don reports “No conclusions yet and maybe there won’t be any, but an interesting trend I’m starting to see is that in this cool wet spring, the conventional tillage does not seem to be living up the reputation of being warmer and easier to till in the spring than no till. That may very well change when the rainfall and temperatures become more like you would expect to see in the planting season.”

Data reveals that cover crops do not appear to be keeping the soil colder.

It appears that our no-till soils with cover crops has consistently been warmer or just as warm as the fall-tilled soils. I am placing the charts below for you to observe the data.

May 15 2013

Root Pit Reveals 40″ Cereal Rye Roots

I am blessed to hear from farmers around the world about their cover cropping adventures. One young man, Brian Scott, from Carroll County, Indiana has generously shared his information with me again this spring. This post is Brian’s report from early May, 2013. To see Brian’s photographs, click here.

We dug a few pits in our field today that has about 40 acres of cereal rye and another 40 of annual ryegrass. The cereal rye had a pretty good stand, but the ryegrass didn’t do so well over the winter. Looks like we may not be the only farm with that problem this year?

Anyway I was pretty excited for our first year cover cropping that we found cereal rye roots down to 40″ today! And we hit the water table below that since everything is still relatively wet from all the rain. I wouldn’t be surprised to see more roots if we could have dug down deeper. That was on pretty good soil that used to have manure applied every year until about 7 years ago when we got out of the hog business.

The ryegrass was on ground with much more clay near the surface, but I was glad to see we had roots down 2 feet where we did get a decent stand.

Both covers were sprayed today. I think I would have liked to keep the cereal rye a bit longer, but with rain in the forecast we didn’t want it getting out of control if we got soaked again and couldn’t spray. These were all seeded into standing corn on 9/19/2012. In all we had about 200 acres of cover this year and have plans to seed at least 400 in the fall!

Thanks Brian! And to everyone who have been sending info…watch for it to be on the blog soon. Thanks to all who are sharing their stories.

May 08 2013

Cover Crop Champions Wanted

National Wildlife Federation has extended the deadline for submitting applications for farmer cover crops champions and outreach cover crop champions – local and regional cover crop leaders who can provide region-specific information and farming knowledge to farmers and crop advisors.

Selected applicants will receive benefits in the form of financial support for time and travel, access to an elite network of other cover crop champions, and training for media and outreach.

Funding for this initiative is limited to certain states in the Mississippi River Basin, so we can only accept applications from champions working primarily in Minnesota, Wisconsin, Iowa, Illinois, Missouri, with consideration of limited applications in South Dakota, Nebraska, Indiana, and Ohio.

Please fill out the NWF Cover Crop Champion Application, and submit to Lara Bryant, bryantl@nwf.org, by Friday, May 24, 2013.

Also view the NWF Road Map to Increased Cover Crop Adoption.

May 08 2013

Cover Crops: Buy One Year, Get Another Year Free

Surprise! That's what our reaction was to the volunteer annual ryegrass growing in our fields nearly 18 months after they were sown. — Surprise! That’s what our reaction was to the volunteer annual ryegrass growing in our fields nearly 18 months after they were sown.

Almost two years to the day I posted an article about Killing Tall Annual Ryegrass.

The problem of a wet and chilly 2011 has resurfaced an ugly head to be a wet and COLD spring of 2013. But over the past week or so temperatures have warmed into the 70’s and 80’s with cover crop annual ryegrass and winter cereal rye having grown tall in some areas of the Midwest. Producers need to kill their cover crops as soon as possible to comply with RMA regulations.

What about the surprise cover crops?

In a previous post I wrote about dormant seed in cover crop species on our home farm.

I showed how radishes were present in soybean fields and how annual ryegrass was coming up even after there was residual herbicide and burndown herbicide applied.

Now here we are in the spring and we have a few new surprises. Fall 2011 planted annual ryegrass and even fall planted winter cereal rye are now growing in the spring of 2013. These cover crops were fully terminated in the spring and summer of 2012; there was effective weed control. So dormant seed has germinated and now grown a full 15-18 months after it was seeded. So yes, cover crops can become weeds.

(But remember, cover crops also suppress weeds.)

So what does this matter?

We have the benefit of a “thin” cover crop and we did not have to pay seed cost or application cost for the second year. In our farming situation it is not a big deal. We terminated all of our cover crops and weeds with a “hot” chemical mix. It is a mix similar to what we used in our no-till fields prior to glyphosate coming on the market. However, if we were growing wheat or oats or barley for grain and straw it could be a problem. Thankfully there are now chemicals to use in cereal crops to eliminate annual ryegrass. I hear reports that Jamie Scott from northern Indiana has seen excellent results with this practice.

We have less winter annual weeds where we have the “volunteer” cover crops and I’m confident our soil health is better where we have the cover crops.

What do we do now?

We enjoy the benefit that we have from the cover crop (even though it is a sparse stand) and we watch to make sure we do not have any cover crops coming back before harvest. The cover crops are now dead and a residual herbicide is applied. Now we wait to plant the corn and soybeans and scout for any additional dormant seed to germinate and grow. A clean harvest is important to all producers. Our goal is to use the information from our own farm to make sure that farmers understand the rewards that cover crops bring and also the risk that comes with the reward. The risk is not huge and it is manageable, but it is risk none-the-less.

This volunteer annual ryegrass was terminated before heading out but it was jointed and would have made a great forage plant. — This volunteer annual ryegrass was terminated before heading out but it was jointed and would have made a great forage crop.

Volunteer Winter Cereal Rye was also growing in the old plot area. The cover crop was terminated well before the corn will be planted.

May 08 2013

Cover Crops and Crop Insurance – Spring Reminders

UPDATE FROM RMA–Haying and Grazing of a Cover Crop – FINAL – 5-8-13

Cover Crops and Crop Insurance on Collision Course again?

Cover Crops and Crop Insurance issues seem to be heading to a collision course again this spring in much of the Midwest. In the Corn Belt wet fields have prevented planting with less than 10% of the corn planted by May 5 across the major corn producing states. In the Upper Midwest and even into Oklahoma and Arkansas 2-19″ of snow fell the first week of May. Dairy farmers are desperate for forage and up to 75% of the alfalfa in Wisconsin and Minnesota winterkilled. Many of those dairy farmers planted cover crop Winter Cereal Rye with hopes of harvesting Ryelage this spring to get some emergency feed after the devastating drought of 2012.

The cold, wet spring of 2013 is causing problems

But the cold wet spring (coldest on record in USA since 1975) may have farmers in a pinch with RMA again despite the Special Provisions for cover crops to the common crop insurance policy for the 2013 cropping year. As of May 8, 2013 the Rye is only around 10″ tall in most of Wisconsin…certainly not ready for harvest by the May 10 RMA cut-off for harvesting and still attaining crop insurance. Even in Indiana the cover crops are ‘exploding” into head after an exceptionally slow start to spring. The fact that these fields are not full of winter annuals that are headed out like neighboring fields should be applauded…so should fields with cover crops be penalized? It appears that farmers in the Upper Midwest have to choose between feed and crop insurance. In much of the Corn Belt the fields are still plenty wet. It is interesting that in some states the fields full of weeds qualify for crop insurance…yet fields with cover crops that have seed heads (instead of weeds with seed heads) do not qualify for cover crops. Go figure.

Please check with your crop insurance agent to see what regulations apply to you.

This field of Winter Cereal rye grew tremendously in very late April and early May. Now it is headed out. Doed this field qualify for crop insurance? — This field of Winter Cereal rye grew tremendously in very late April and early May. Now it is headed out. Does this field qualify for crop insurance?

Should farmers be penalized in a wet and cold year for growing a cover crop instead of having a field of winter annual weeds? Common sense says that a cover crop is better for agriculture than weeds.

Apr 17 2013

Part 3- Do Cover Crops Keep the Soil Colder in the Spring?

Fact or Fiction? Cover Crops that Survive the Winter Keep the Soil Colder in the Spring than Fall-Tilled Soil – Part 3

As of today (April 17, 2013) there is 0% corn planted in Iowa and Indiana with 1% in Illinois and Ohio. It is now wet and cold…not just cold. As my brother Don takes soil temperature readings in no-till soils with cover crops, no-till with out cover crops, and fall tilled soils, we are trying to get an idea if no-till soils and or no-till soils with cover crops keep the soil colder than fall tilled soils. These trials are being conducted in central Indiana and should be a pretty good measurement for much of the Eastern Corn Belt. I am in northern Wisconsin today where there are snow covered fields with 6-8″ more snow coming in the next 36 hours. The readings from central Indiana don’t mean much in Minnesota and Wisconsin…but, I believe they are still instructive.

April 5-12, 2013 weather data

The temperatures at the local weather station showed that the actual average high for the week was 70.6° (historic average is 61°) and the actual nighttime average was 49.9° (historic average is 40.3°). This was the first week in the past several weeks that have been warmer than average. There was nearly 1 inch of rain during the week.

Soil temperatures increased dramatically during the week

Warm weather really helped increase the soil temperature, almost 10° in some of our trials. It is interesting to see that the no-till soil without a cover crop was the coolest by 1°. It was also the wettest soil last week and certainly appears to be the same on 4-12. The warmest soil was the no-till with cover crop. Not by much but it is warmer than the fall tilled soil by ~0.5°.

With heavy rains in the area this week it will be interesting to see what happens in each soil. We hope to get an idea of what kind of earthworm activity we can find, but that might be difficult in the muddy sites.

Improved water infiltration may be showing springtime benefits

As you look at the photos notice the moisture content on the surface of the soil. There are two observations or reminders that we should consider. When we took compaction readings last summer (2012) we saw a significant benefit where we had cover crops compared to the no cover crop check. These soil temperature tests are taken from those same plots. Another observation is that I have found improved aeration and percolation where we have had cover crops (long-term no-till with cover crop) verses long-term no-till without a cover crops and a spring tilled soil. I believe we are seeing that the cover crop is giving benefit again this spring in these areas.

What are you finding on your farm?

Readers would be interested in knowing what is going on in your area and on your farm. Please comment below and share what you are finding. Thanks, Dave

The soil temperature in the long term no-till soils on 4-12-2013. Note how waterlogged the soil looks. — The soil temperature in the long-term no-till soils on 4-12-2013. Note how waterlogged the soil looks.

The soil temperature in the long-term no-till soil with a cover crop. Note that the soil looks drier and it is also the warmest reading this week.

The soil temperature in the fall-tilled soil on 4-12-2013. The soil doe not look as wet as the no-tilled soils. Maybe the water went down the cracks! — The soil temperature in the fall-tilled soil on 4-12-2013. The soil does not look as wet as the no-tilled soils. Maybe because the water went down the cracks…

Apr 09 2013

Part 2- Do Cover Crops Keep the Soil Colder in the Spring?

Fact or Fiction? Cover Crops that Survive the Winter Keep the Soil Colder in the Spring than Fall-Tilled Soil – Part 2

On Friday April 5, 2013 my brother Don recorded the temperatures in soils on our home farm near Greenwood, IN (central Indiana). The previous week Don took soil temperatures coming out of a colder than normal March. The results showed very similar temperatures in soils at approximately 4″ deep in fall tilled soil, long term no-till soil, and soil covered with an annual ryegrass cover crop.

April 2013 is off to a chilly start in central Indiana

The first week of April saw chilly day and nighttime temperatures in the area. The average daytime temperature was 53.5 degrees (normal is 58.71 degrees) and the nighttime temperatures were 30.8 (average 38.29 degrees). The soil temperatures gained a few degrees in each area.

Soil temperatures did increase during the week

While the soils are not warm enough to plant corn in yet they are getting closer. No one in the area has started any planting yet but the soil temperature readings show that all of the soils tested are getting close to being warm enough to make sure the planter is ready and seed is in the shed ready to go to the fields.

Don’s observations

The long-term No-till area had the most surface soil moisture (not wet but definitely quite moist)
The fall tilled soil was crusted over and had cracks in the soil
The soil covered with Annual Ryegrass was not “wet” and it had no cracks in the soil
Don told me that he heard from Barry Fisher at a recent cover crop field day that soil biology starts becoming active at around 38 degrees soil temperature. Each of the soils are well above that temperature.
During the next testing session Don will also be testing for soil moisture and taking some earthworm counts in each of the soils.

Soil temperature in the fall tilled soil 4-5-2013

Soil Temperature in the long term no-till plot (check plot) 4-5-2013

Soil temperature in the Annual Ryegrass cover crop plot 4-5-2013

Mar 30 2013

Do Cover Crops Keep the Soil Colder in the Spring?

Fact or Fiction? Cover Crops that Survive the Winter Keep the Soil Colder in the Spring than Fall-Tilled Soil

This is a question I get over and over again. And most of the time it’s not really a question. It’s actually someone stating to me why they are not going to plant cover crops. But is it really true that a surviving cover crop will keep my soil colder than a conventionally tilled soil?

Several years ago in March I stopped at a cover crop test plot on the Indiana/Ohio border. While I was there I checked the soil temperature where cover crops had survived (Annual Ryegrass and Winter Cereal Rye) to see if it was indeed colder than the tilled soil that surrounded the plot.

Surprising Results

What I found was a bit surprising considering the conventional “widsom” I commonly heard. The soil temperature at 4″ depth was warmer by 1-2 degrees where we had a surviving cover crop than in moldboard plowed dark soil. I sampled on a sunny day when the temperatures were in the 40’s.

Since then I have taken comparative soil temperatures in many locations where no-till was done, where there was no-till with cover crops, and where there was fall tilled soil. In nearly every instance the area where there was a cover crop the soil temperatures were equal to or above the fall tilled soil temperatures. Each of these samples were just taken one time – a snapshot test in time.

More Testing

This spring my brother Don Robison is taking soil temperatures and photos of a soil thermometer from our home farm near Greenwood, IN. He started taking these photos on March 29, 2013. The plan is that Don will take soil temperatures for four or five consecutive Fridays – in annual ryegrass, in no-till soil (that has some winter annuals present), and in fall tilled soil. And since March of 2013 has been quite cold when compared to recent years, the results should be interesting.

Results Will Be Recorded

Each week I will post the temperatures as Don send them to me. Below you can see the temperatures from March 29. Be sure to check back weekly for the results.

Do Your Own Experiment

Send me temperature readings and photos (phone camera quality is fine) and I’ll compile some data from different parts of the country (world) and pass the data along. Please let me know your soil types and general weather conditions when you send in your reports.

The soil temperature on March 29, 2013 at approximately 4 inches in fall tilled soil.

The soil temperature on March 29, 2013 at approximately 4 inches in an annual ryegrass cover crop.

Soil temperature reading on March 29, 2013 in no-till soil. — The soil temperature reading on March 29, 2013 at approximately 4 inches in no-till soil.

Mar 21 2013

Cover Crops are Working in Iowa

Cover crops are working in Iowa!

While that may not mean much to my eastern corn belt friends it means a lot in Iowa and the upper Midwest.

Working with Sarah Carlson from Practical Farmers of Iowa and Tom Kaspar from ARS at Ames, Iowa, we’ve been attempting to identify what cover crops will be most compatible with common Iowa farming practices – in particular the use of longer season corn hybrids and soybean varieties, as well as an abundance of corn after corn (CAC) management strategies. Establishing cover crops like radishes and annual ryegrass into these situations hasn’t proved to be easy.

Aerial application of cover crops (annual ryegrass, crimson clover, radishes, etc.) into corn in Ohio and Indiana has been very successful. However, in Iowa it has not worked with quite as much success. Cereal rye may actually be the best alternative. While it may seem a bit “simple” to plant mainly cereal rye most years, there are significant benefits to using cover crop rye in a corn after corn scenario, mainly because it has been shown to reduce Goss’s wilt.

September 5, 2011 planted Annual Ryegrass compared to Winter Cereal Rye in central Iowa in April 2012. Note the dramatic difference in winterhardiness. — September 5, 2011 planted Annual Ryegrass compared to Winter Cereal Rye in central Iowa in April 2012. Note the dramatic difference in winterhardiness even after a very mild winter.

Sarah commented that besides using more winterhardy species for greater success, it is also very important to not interseed the cover crops into green corn or green soybeans. She says, “Pushing radishes with aerial seeding into a dense, dark corn or soybean canopy is unsuccessful.”

But if the right cover crop is used in Iowa and managed well then covers work very well! Rod Swoboda from Wallaces Farmer published an article written by Sarah Carlson reflecting work that was overseen in Iowa by PFI.

Mustard as a Cover Crop