Plant Cover Crops

Learning about the benefits of planting cover crops.

Annual Ryegrass

Root Pit Reveals 40″ Cereal Rye Roots

Rye Pit

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.

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

 

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

Earthworm Population Corn Field Experiment

Robison Farms in the Greenwood, Indiana area have been no-till farming since the late 1960’s. The field that these videos were taken from has been no-tilled for approximately 20 consecutive years.  With the wet spring of 2011 the  gentleman that now does the field work for dad decided to chisel plow and disk most of the farm where my brother lives.  Thankfully the area where the cover crop plots were was not tilled.  In mid-August I decided to dig around in the field where the cover crop plots were and in areas where the field was tilled (again, it had been no-till for approximately 20 consecutive years).  Dad tells me that in those 20 years the organic matter has increased by at least one (1) percent.  So the soil on this farm should be pretty healthy.  In 2010 the soybeans averaged around 55 bu/acre in a very dry year.

Earthworms are a good indicator of soil health. Erarthworms enhance soil health as well.

I have included three different videos where I am taking earthworm counts in this post and I believe you will find them very interesting.

The first video is of earthworm channels in no-till where we had annual ryegrass as a cover crop.

The second video is taken in an area of the field where I counted earthworm channels where we had no cover crop in the tilled soil.

The third video is where I counted earthworm channels in no-till where we had a cereal rye cover crop.

Observations:

  • There were always more earthworms in no-till with cover crops (watch the videos to see how many more…).
  • There were more earthworms in the tilled soil than I anticipated.
  • The corn looked healthier (with somewhat larger ears) in no-till and with cover crops than in the tilled w/o cover crops area.
  • There were more earthworms where there was no-till w/o cover crops than in tilled area w/o cover crops.

Cover Crop Annual Ryegrass – Kill it dead!

By mid-October it was very evident that there was A LOT of volunteer annual ryegrass in this field. At that time the question was whether it would survive the winter...the answer was "yes it would". So now what? KILL IT DEAD this spring!

I was recently in a field of ryegrass cover crop that we had looked at earlier and there is still a lot of ryegrass in the field.  That sounds good, right? It’s unfortunate that it was volunteer annual ryegrass.  This producer had not followed the proper steps to killing his annual ryegrass.

We need to kill the annual ryegrass cover crop in the spring.  Take a look at this site from the Oregon Ryegrass Commission on how to have the best opportunity to kill annual ryegrass cover crops. Now, there are questions brought up occasionally about whether killing volunteer annual ryegrass is more difficult to kill than ryegrass that was planted the previous fall.  I’ll ask the experts to weigh in on that question in the comments section…I do not know the answer to that question!

This beautiful field of cover crop annual ryegrass will need to be killed before planting season.

What if a cover crop dies over the winter…was it still valuable?

As I take phone calls and conduct meetings I ask producers if they want to have the cover crop they are choosing to overwinter or die during the winter.  I’d guess that the answer as split 50/50. The biggest reason for wanting the cover crop to die is that producers don’t want to have “to mess” with killing a crop in the spring of the year.  Other advantages that folks mention is that they believe that the soil will be warmer if there is not a living cover in the field.

This mixture was planted on time but had very little moisture in the fall of 2010. All things considered it is a beautiful stand. However, the crimson clover is so short that I hope that it overwinters so the producer can get "maximum" nitrogen benefit for the 2011 corn crop.
On November 17, 2010 we found annual ryegrass roots 40" deep after just 10 weeks of growth. We want this field to overwinter...but we already have accomplished nutrient management goals by holding nutrients from the manure applications. If the field overwinters I believe we may find roots 70" deep when we dig in April 2011.

Advantages of having a “short-term summer/fall cover crop” is that you should still control the majority of the winter annual weeds, many legumes will still produce a good amount of nitrogen before winter (Austrian Winter Peas, Cowpeas, Crimson Clover, Berseem Clover, Field Peas, etc…).  Radishes and turnips will do their nutrient scavenging and plow pan cracking work before the killing freeze too. Even annual ryegrass might have produced a pretty good root system before it goes winter dormant (or dies) depending on the seeding date/fall growth. (See  details of what we found in an annual ryegrass field in the fall of 2010.)

So what would be the advantage of a winterhardy cover crop?  Improved spring erosion control, more living roots in the soil for a longer time period, more spring-time earthworm activity, more nitrogen produced (from legumes) and over a longer time period, minimal soil temperature change (versus a dead cover crop or no cover), a longer grazing time period, to name a few.

Disadvantages of the crop overwintering would include the risk of a very wet spring causing trouble getting the crop killed, possibly cooler spring soil temperatures, and possibly some reasons that don’t come to mind.

If using a legume like clover it seems to be advantageous to have it overwinter, however Berseem clover possibly produces the most N of any legume…and it is sure to winterkill in Midwestern winters.  And I like Berseem clover when it fits the producers situation.

So, does it matter if the cover crop survives the winter…even if it dies when you expected it to survive?  My answer is that there are still benefits on most cover crops IF they were productive in the fall/winter.  If you have a late planted cover crop that has minimal growth in the fall and then it dies…you possibly “wasted” money.  Do your best to plant cover crops in a timely fashion.  Give them the best opportunity to do their best!

Annual Ryegrass Roots Video – 40″ deep in 2 1/2 months!

I was in western Pulaski County of Indiana again yesterday afternoon (11/16/2010) at the Leman farm. This is the third year that the Leman’s have used cover crops. Curt Leman dug some pits for us so we could see what kind of rooting depth we have achieved since the annual ryegrass was planted on Sept 4, 2010. When I got in the pit I was very pleasantly surprised! I found ryegrass roots that are already 40″ deep! Watch the video to see what other goodies I found!

After digging out the section of soil that had the dark band we found that we actually had corn roots from the 2010 crop that were at least 36″ deep. My friend from Michigan who is a “corn guru” tells me that in most soils in most years that corn roots go 18″ deep…so we gained approximately 18″ greater depth of corn roots by using annual ryegrass for one year…impressive isn’t it!?! And, we didn’t dig deeper than 40″ so possibly the roots went deeper than that. I believe that helps explain our improved corn health and yield where we had ARg as a cover crop vs where we had no cover crop (again, see previous post).

In the photo you see the dark band of soil found at the 30-36″ soil depth. The following video reveals what I could not see when in the pit…

I anticipate we will dig in the spring at the Leman farm again. What we found after 10 weeks was literally amazing!

Is Annual Ryegrass a weed – part 2

These annual ryegrass seedlings were around 3-4″ tall underneath the soybeans. I’d imagine they could be 2-3 feet tall at harvest.
The soybean field looks great! But underneath the green foliage you will find lots of annual ryegrass coming.

Today, August 3, 2010 I visited some fields in Whitley County Indiana to look at fields where annual ryegrass was not killed quite perfectly this spring.  Even though the soybeans look awesome there is a problem lurking under the bean canopy.  That problem is a fairly thick stand of annual ryegrass.  I found ryegrass in the 2-5″ tall range.  My guess is that in one field we checked that there is close to 10-15#/acre seeding rate equivalent.  The grass is relatively thick in many areas.  While the beans are planted in 15″ rows there is still enough sunlight hitting the ground to keep the ryegrass growing and green.  The biggest problem is yet to come when the beans start to drop their leaves and the ryegrass gets more sunlight and takes off growing more quickly. On thing about annual ryegrass…it loves Nitrogen and the soybeans are providing plenty for it.  I’m afraid that the ryegrass could be 2-3 feet high at harvest time…making for a “fun” harvest.

This is why it is so vital that annual ryegrass is “killed dead” in the spring.  Count on two applications of glyphosate.   More will come on this in a later post.

Is annual ryegrass a weed?

Forage and cover crop 030
Unfortunately the annual ryegrass was not killed in this field...it is heading out, likely to produce viable seed. Proper weed control is vital with annual ryegrass.

I was visiting with a weed scientist from Purdue yesterday.  He is an excellent scientist and gifted at weed ID as well.  I asked him to work on a project and as he and I were discussing that he made a comment that I know needs to be ruminated upon.  He asked me if I like annual ryegrass as a cover crop.

I do…usually.  It is not my number one choice in many instances but it sure does some wonderful things to the soil environment.

His main concern is that annual ryegrass “is only killed properly 3 out of every 5 years.”  I’m not sure of that percentage but I do know that in 2010 in NE Indiana there are many acres where there is poor weed control on the annual ryegrass.

Whoops!  I just called annual ryegrass a weed!  Well, it is a weed now, because it was not controlled and it has become a problem in several fields.  Unfortunately the ryegrass is fully headed out, pollinated and producing viable seed.  For years to come it may be a problem – especially in wheat, oats, barley, and possibly row crops.

  • Is annual ryegrass an excellent cover crop?  Yes.
  • Does annual ryegrass take better management than most cover crops?  Yes.
  • Is annual ryegrass a weed?  Yes, it could become one; and unfortunately in many areas it became a weed in 2010.

Annual Ryegrass…leading the new frontier of cover crops

hand with ARG roots
Annual Ryegrass has very deep, fibrous roots.

Annual Ryegrass is one of the more popular and also one of the more vilified of the cover crops.  Those that love it cite the deep fibrous roots and excellent soil tilth improvement.  Those that loathe it cite that it does not always survive the winter…or that they can’t kill it if it does!

Thankfully there are a few very good winterhardy varieties on the market and the method of killing annual ryegrass is becoming more refined and dependable.  Annual Ryegrass has many benefits and a few disadvantages.  I list them below.

Advantages of Annual Ryegrass:

  • It is a deep rooted cover crop that helps mine minerals from deep in the soil profile.
  • It is an excellent erosion control crop.
  • It is a luxury consumer of nitrogen and tremendous scavenger of N.
  • It works well aerial applied into corn and soybeans.
  • It also makes an excellent forage crop.
  • Corn following annual ryegrass often yields more and is more drought tolerant due to  depth of roots and holding N in the soil from previous fertilizer applications.
  • Excellent with manure applications…holds N in soil profile, out of tile drains.
  • And more…

Disadvantages of Annual Ryegrass:

  • Many varieties are not winterhardy (many rarely make it through the winter alive).
  • It may be difficult to kill in the spring.
  • It takes more management than many other cover crops.
cover crop 2010 044
Annual Ryegrass in the spring of 2010. Planted in 15" rows, this erosion fighting cover crop was a huge success.
cover crop 2010 040
The root structure on Annual ryegrass is impressive. Even when planted in 15" rows the roots filled in between the rows.