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.

 

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 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…

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 fall tilled soil 4-5-2013
Soil Temperature in the long term no-till plot (check plot) 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
Soil temperature in the Annual Ryegrass cover crop plot 4-5-2013

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.

 

 

 

 

 

 

Can Cover Crops Become Weeds?

In a previous post I wrote that cover crops can suppress weeds.  And many farmers are planting them with that primary benefit in mind.

But, can cover crops become weeds?

Unfortunately, the answer is “yes, they can.”  Obviously we never want this to happen on our farm.  And with good management practices, we can lessen the possibility that it will.

Two species that require precise management are annual ryegrass and radishes. Both annual ryegrass  and radishes benefit the soil tremendously and have been shown to increase profit per acre, but both must be carefully managed as well. Specifically, there must be a comprehensive plan for terminating annual ryegrass. If you are not absolutely clear on how you are going to do this, you should not plant it. Likewise, with cover crop radishes, you need to be absolutely clear on what you are buying and when the seed should be planted.

It only takes a few annual ryegrass plants that produce seed to create a weed problem - especially if wheat is in the rotation.
It only takes a few annual ryegrass plants that produce seed to create a weed problem – especially if wheat is in the rotation.

This is why Hans Kok, from the Indiana Conservation Cropping Systems Initiative often tells farmers that are trying cover crops for the first time to start with a few acres of oats and radishes as a cover crop.  His thinking is that because both oats and radishes die over the winter that farmers will not have to worry about terminating the cover crop in the spring.  And I agree with Hans on this.

However, cover crops are becoming more popular and many producers are convinced that they are excellent at killing weeds and cover crops.  While Ag Chemical companies have shied away from making too many recommendations on killing cover crops, farmers are confident in their abilities to “figure it out” and make cover crops work on their farm.  Why use “boring” oats and radish?  Let’s use Annual Ryegrass!

Don’t get me wrong, Annual Ryegrass is a fabulous cover crop with tremendous value as a cover crop and forage.  But, it does take more management than many other cover crops.  Annual Ryegrass provides high reward with some additional risk.  On our home farm we sprayed our soybeans three times to make sure all annual ryegrass was killed.

Planting Radishes too early or planting the wrong Radish can create a problem with seed production on the radishes...and you don't want that!
Planting Radishes too early or planting the wrong Radish can create a problem with seed production on the radishes…and you don’t want that!

I’d love to hear your “formula” for annual ryegrass control. Have you noticed any difference with terminating annual ryegrass on different soil types? Different temperatures? Different additives? Different times of the day?

 

Be Aware of Dormant Seed in Cover Crops

As Oregon and other west coast farmers try to keep up with the demand of getting seed back to the Midwest from their newly harvested crops, we are beginning to see some potential issues with just-harvested seed.

In the past, supply was usually greater than demand at harvest time. However, seed companies and farmers now have been clamoring for the seed…it seems from right out of the combine in Oregon!  In some ways this is very exciting, but in other ways it’s challenging.

One of the the bigger challenges outside of logistics is seed dormancy.  In the following few paragraphs we will look at two species that seem to have risen to the top of the heap when looking at seed dormancy issues.

Seed Dormancy Issues

Radishes

Here are just the few events I’ve personally witnessed with radishes:

  • In the fall of 2010 I saw pictures of big radishes in dry beans in the thumb of Michigan.
  • In May of 2011 I saw pictures of radishes 15″ tall (as tall as the corn).
  • In the spring of 2012 I saw radishes coming in the corn at our family farm.
  • In the fall of 2012 I saw radishes and annual ryegrass coming up from seed that was planted in September 2011.

How do these events happen?  I know that for sure the weed control on our home farm was “excellent” all season long and that there was a “follow-up” herbicide application to make sure that there was outstanding weed control.  However, there they were!  We had BIG radishes in the soybeans at harvest time.

Beans are ready for harvest but radishes can create a headache if not controlled with season long scouting.
Beans are ready for harvest but radishes can create a headache if not controlled with season long scouting.
How would you like these running through your bean head? Me neither. Thankfully they did not cause any issues but we need to be watchful and use full season herbicides if we don’t want to ever see this.

How could these radishes be in the soybeans?

Radishes have a small percentage of “hard” or “dormant” seed.  Usually 4-5% of what is sown will not germinate right away, but will instead come up at a later time, from 1 season to 50 seasons later.  While this will rarely ever cause problems, we need to be aware of it.  The 2012 drought, combined with the heat and later rains, proved to be a great environment for radishes to start growing in August.  By harvest time in October we had very big radishes.

Be sure to talk to your seed supplier about when your radish seed was harvested. You will possibly have less issues with radishes that were harvested the previous summer instead of the previous few weeks.

These radishes were easily killed with the second spray of the season. However, I wish that the initial residual herbicides had controlled them as we anticipated they would have.
These radishes were easily killed with the second spray of the season. However, I wish that the initial residual herbicides had controlled them as we anticipated they would have.

Annual Ryegrass

Annual ryegrass gets a lot of hype and also a lot of guff.  I’m not sure which one bothers me the most.

Annual ryegrass has many outstanding qualities as well as some challenges.  Dormant seed is one of those challenges.  Annual ryegrass needs to “cure” for a time – or to dry fairly thoroughly for its germination to be consistent – the 90-95% that we expect and appreciate.

However, when we go from “combine to airplane or drill” in a very quick time period we are “rushing” the seed so fast that some of it lays dormant for a time.  How long?  Maybe a few months or maybe a year.  On our home farm we had an outstanding kill on our annual ryegrass (and everything else).  Yes, it took two applications to accomplish that but we were very well pleased with the kill on our cover crops.  And we were thrilled with the results!

However, when we were looking at our corn plots in August I gave the “uh-oh” to Hans Kok, Dan Towery, and my brother Don Robison.  As in “uh-oh, we have annual ryegrass coming up.”  In this case it was not a big deal because it didn’t bother the corn harvest and we’re planting soybeans in the spring.  But, what if we were going to wheat?  We would have sprayed and killed the young seedlings if we noticed them becoming a problem.

In the middle of August we were seeing annual ryegrass and radishes coming up that had been SOWN THE PREVIOUS SEPTEMBER!
By November we had vigorous growth and a thicker stand than we had the year that the cover crops were actually sown.

There is no doubt that cover crops are a valuable tool.  But with the demand for cover crop seed, I think we will have issues that some of us never dreamed of –  in addition to the benefits that are beyond our imagination.

To achieve the best possible benefit and profitability we need to manage well.  The cover crops that came back into our corn should be of great benefit to next year’s soybean crop – even though we didn’t plant them in the fall of 2012, but rather in the fall of 2011, a year earlier!

So should we NOT use annual ryegrass or radishes?

Of course we should use them. They are outstanding species for cover cropping.

Should we buy seed a year in advance?

That is probably not feasible for most farmers and you surely need a rodent proof storage area!  And good luck finding enough “extra” seed.

Manage Well

Since we’re learning that cover crops increase profitability on the farm, our focus needs to be on proper management. Very simply, use a long-lasting residual herbicide, scout and spray as needed, and be aware that some cover crops species have dormancy issues.  If you are going to follow with wheat, be sure to apply herbicides that kill annual ryegrass in the fall so the annual ryegrass  does not live and cause issues in the wheat the following summer.

It all comes down to managing your cover crop well.  Most farmers have few if any problems, but stay alert. You must be on guard to achieve the greatest benefit from your cover crops.

Cover Crops Provide Improved Corn Yields in On-Farm Trial

All of what is reported below was accomplished after only one year of cover crops.  This work was inspired by a conversation Don and I had last winter with Dr. Eileen Kladivko from Purdue University.  As I say in cover crop meetings,

Don’t expect a miracle the first year – but look for one.

Over the exceptionally dry and super hot late-spring/summer months of 2012 my brother Don Robison collected “plant-health” related data on our corn field at Robison Farms near Greenwood, IN.  Don took data on the corn  from each area of the cover crop plot we planted last fall over the top of a soybean field as well in the “check area” (no cover crop area).

The data he took throughout the summer included plant chlorophyll readings, plant height, and compaction readings.  I presented some of the chlorophyll data on the CropLife Webinar and at several cover crop meetings this summer (and more is posted below).

On August 15th Don and I took hand harvested yield checks from each area and from the check area.   The data on the corn yield was almost identical to what we found with the chlorophyll data and compaction data. Where we had the healthier plants all season long (more “green-ness” and deeper roots) we had higher yields.

To figure yield we utilized this formula we found at a Purdue University agronomy website.

Each cover crop treatment out yielded the “no cover crop check”. The top three yielding plots also had the least compaction and highest chlorophyll readings through out the drought stricken summer.  The check plot yield was 105.24 bushels per acre.  The top yield estimate was 164.82 bushels per acre.

 

The area where the plot was had a 24″ water line was installed by the county in 2009; so it was intended to be a “rescue disturbed soil trial”.  The corn was not harvested directly over the water line but it was where the soil from the water line was mixed in with the top soil.  In 2011 the field was in Soybeans and yielded 48 bushels/acre.  In 2010 the field was corn and yielded 198 bushels/acre.  The whole field has been no-tilled for most of the past 20 years (there were some years with conventional tillage done – mainly in the early 90’s).  175 Units of N were applied (100 units (28%) with the chemical burn down application early season and 75 units side dressed (28%) in early May).

Rainfall from May 1 to July 31 was 2.24″ (with only 0.75 from May 1 to July 19).  There were 42 days over 90 degrees and 8 days over 100 degrees during that time.  All time record dry and heat was recorded in July, 2012 in the area.

Don took chlorophyll readings weekly (one week missed in July due to a family vacation).  He took 30 chlorophyll readings per plot per sampling date.  He also took multiple plant height readings each time as well.  He followed the manufacturers instructions on the chlorophyll readings and penetrometer tests.  Don spent a lot of time in this field so we could all have this data!  Thanks to The CISCO Companies for providing the seed, equipment, and Don’s labor to collect this data.

 

This chart shows the percentage above the no cover crop area (the “check”) compared to the different cover crop mixes. The two comparisons on the far right are from a soybean study we ran where we had cover crops two consecutive years compared to one year (more data and a post coming soon on this study).

Observations:

  • The plot areas that rated healthier (more green-ness and taller) yielded the best.
  • The plots areas where there was less compaction yielded the best
  • The plots with annual ryegrass did not fare as well as some others in this drought year – yet was still considerably above the check.
  • Not all plots with radish were “top” yielding – however two of the top three yielding plots had legumes plus radish.
  • Plots with legumes were generally healthier all season long and their yield reflected that.
  • I doubt that the whole field will average over 100 bushels/acre.  As with all hand yield tests they are estimates but I believe that the comparison is very accurate.
  • The Austrian Winter Peas, Crimson Clover, and Appin Turnips overwintered “beautifully” and were growing aggressively when sprayed at burndown.
  • There was a considerable amount of earthworm activity in the cover crop area but only a few earthworms were found in the “check” area. That is unfortunate because 2 acres were covered and 48 acres were not!
  • There were more corn roots in the plot areas we dug vs. the check area (watch for a new post coming on this soon).
  • There was more moisture in the soil where the cover crop plots were compared to the check area.
  • The soil structure was considerably better in each cover crop plot vs. the check area.
Don recorded over 180 chlorophyll readings in each cover crop plot and check plot over the summer.

 

The check plot had 175 units of nitrogen plus the whole field had been soybeans the previous year. While the annual ryegrass blend plot was above the check all season long it was not up to the desired level until after the July 19 rain event.

 

The plot with the Oats and Rye and Appin Turnips was impressive most of the spring and summer. It was at or above the desired rating until August. It was very impressive right after the July rain event and that is possibly why it had the second highest estimated yield. By the way, the turnips did live through the winter.
All season long I was convinced that the plot where the Austrian Winter Peas and Radish were was going to have the highest yield based on the data shown above (and plant height readings). It beat the second place entry by less than 1/2 bushel in the yield estimate.

Terminating Cover Crops – Use Residual Herbicide

Terminating cover crops is part of the “stepped-up management” that using cover crops requires.  Over the past month I shot videos about killing annual ryegrass, killing crimson clover, and about the difference of killing cereal rye and annual ryegrass.  In each of the videos I examined the importance of killing the cover crop…and killing it dead.  Overall, most of the cover crop fields that I have seen had a very good burn down.  In more than a couple of instances it was obvious that the applicator missed a few (if not many) spots or strips.

Terminating Cover Crop Radishes

In the cover crop plots where Radishes were in the mix we now have plenty of Radishes in the corn!

But burndown is not all that we need to be concerned about.  In 2011 I saw photos from fields in Michigan that almost made my heart stop!

A corn field in southern Michigan had radishes that were taller than the knee high corn. And a field of soybeans had large radishes in it at harvest time.  Thankfully the corn field yield was not affected, but areas of the soybean field could not be be harvested.  At $12-13/bu soybeans that was an expensive lesson.

Applying glyphosate once a season without using a residual herbicide does not provide adequate weed control. These radishes germinated after the spring glyphosate application.

So how did these situations happen?  In both instances the producers used glyphosate for their burndown and did not  use (or had not yet used) residual herbicide.  Of course the radishes were not the only “weed” in the field, but it was the focus of the growers!

Terminating Cover Crops at Robison Farms

At Robison Farms in Central Indiana we have two issues going on in our fields this spring of 2012:

#1) Radishes are coming in the corn and soybeans, even though we did apply a residual herbicide!

#2) There are more annual ryegrass escapes than I’d ever like to see. We actually had very good burndown and we used residual herbicide too.  Note that these are NOT the only “weeds” that we have growing in the fields.  I cannot remember a year when we’ve seen so many winter annuals and broadleaf weeds survive residual herbicide.

My brother Don has been scouting our fields and he reports seeing ragweed, morning glory, cocklebur, Queen Anne’s lace,  and a variety of other broadleaf weeds across our 300 plus acres.  The weeds aren’t thick, but there are too many of them. So we’ve concluded that it is not “just the cover crops” that are escaping.

So what is the advice here?  Make a commitment to scout your fields for weeds, whether they be “cover crop species escapes” or other weed pressure.

  • Excellent weed control is vital for top profits in cash crops.
  • Use residual herbicide in corn and soybean fields.
  • Scout fields looking for escapes and other weed issues.
  • Terminate all escapes before they produce viable seed.
  • Realize that cover crop radishes do have hard seed and you most certainly will see radishes in the spring.
  • Oilseed crops (brassicas like radishes, turnips, rape, canola, kale, mustards) can stay viable in the soil for years. Scout each year in fields where you have had these brassicas.
  • Scout for brassicas later in the season as well.  This should not be an issue but don’t take a risk of losing acres of soybeans.  The soybean field in Michigan had no residual herbicide applied but the radishes that caused the problems came up later in the season (probably late July or early August gauging from their size at harvest).
  • In some years like 2012 (even if you did not use cover crops), you will have more weed pressure than other years.  Eliminating all weed pressure is important!
The casual drive-by look at this plot looks like we achieved a great kill on this annual ryegrass cover crop. The corn looks great, the grass looks brown and dead, but...
...in more than one area I found annual ryegrass "escapes" that are heading out or nearly heading out. These plants need to be sprayed right away so they will not produce viable seed.

 

Killing Cover Crop Annual Ryegrass – How Are We Doing?

This Annual Ryegrass plant was almost killed. But almost is NOT good enough!

Over the winter of 2011-12 I did nearly 55 cover crop meetings across the Midwest.  And one of the “hottest” topics was how to kill annual ryegrass in the spring. This topic is almost like the Tim Tebow of the cover crop world. Some have no problems managing it and some hate it (cannot get it killed).

During the meetings I suggested that farmers read a really good article on Ag Web that I was asked to help write along with Mike Plumer, Dan Towery, and a few others.   In the article Mike Plumer and Dan Towery both give excellent advice on killing annual ryegrass.  I have also written quite a bit on the blog about killing tall annual ryegrass.  The one theme we make sure producers know is that they need to kill the annual ryegrass dead!

At this point many farmers swear that they have no problems and others just swear!

I have done a couple of videos that I hope help in this matter.  They are pretty representative from what I have seen this spring across the Eastern Corn Belt.  The first video was taken before spraying, the second taken after spraying was done. A third video shows the difference between killing annual ryegrass versus killing cereal rye.

One of my key points is that we be ready to spray again if we see green.  Don’t assume that if you see green that the initial herbicide application will eventually work.

Please forgive the wind noise on the second and third videos. I used the mic but it was very windy.

 

Annual ryegrass on the left and cereal rye on the right. Look at the massive amount of cover on the annual ryegrass!
This green leaf tells us that the plant is not entirely dead. While we may have a 99% kill this plant will end up producing seed if it is not terminated.