Plant Cover Crops

Learning about the benefits of planting cover crops.

cover crop radishes

Cover Crop Field Day Set in Blooming Prairie, MN

PileDriver at Hagan Farms 2 33 days
This Radish was planted in late July 2013 and after 33 days has tremendous growth. This mix included oats and crimson clover and radishes.

Cover Crops will be the main topic of discussion on September 4, 2013 at a cover crop field day and meeting in Blooming Prairie, MN. I have the privilege of speaking at this event as we look at cover crops on prevented plant acres.  We will also look at what cover crops work best in the upper Midwest.  We will be on Brad Hagan’s family farm and possibly look at Dale Ramsey’s farm too.  Please note that we will be looking in root pits (where the action really is)!

I received this note from Legacy Seeds representative Andrew Heath about the field day/meeting:

“We  plan on structuring the event much like an open house with designated times where you will be able to address the crowd. We will start the event at 10 am and have you speak from 11 to 11:45 and again at 1 to 1:45. There will also be transportation to the cover crop plot and some of the field that you, TJ, Brad and I visited earlier with root pits dug. This will happen from 12 to 1 and 2 to 3.”

I have seen the plots and have added photos here on this post to entice you to come if you are in the region.

As a side note, Hagan farms will be no-tilling corn into these fields in 2014.  We’ll follow-up on these fields next spring and see how these fields compare to others that did not have a cover on them.

This prevent plant field had plenty of nitrogen from manure to capture. Hagan farms used a hybrid brassica and spring barley to secure the nitrogen and Berseem clover to produce more N and provide better soil health.
This prevent plant field had plenty of nitrogen from manure to capture. Hagan farms used a hybrid brassica and spring barley to secure the nitrogen and Berseem clover to produce more N and provide better soil health.

Cover Crops and Prevented Planting Guidelines

There are thousands upon Thousands of acres - mainly in the upper Midwest not planted in early June 2013.
There are thousands upon thousands of acres – mainly in the upper Midwest still not planted in early June 2013.

Over the past few weeks I have heard from countless farmers in Wisconsin, Minnesota, Illinois, Missouri, Michigan, and Iowa that are considering taking prevented planting on all or parts of their farms. Growers Edge just published an excellent piece Prevented Planting Guidelines. 

Also see my articles on Prevented Planting Row Crop Acres – Which Cover Crops Can Help? and Summer Annual Grasses for Cover Crops for Prevented Planting Acres that may also be helpful.

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.

Is it Ever Too Early to Plant Cover Crops?

Is it ever too early plant cover crops?  YES.

As many of you have figured out, I sell seed for a living.  I also have been a farmer or involved on the farm since I was a little boy.

But first and foremost I am an agronomist.

The temptation of a seed salesman is to recommend planting a cover crop either too early or too late – and then somehow justify it. However, as an agronomist and a former farmer, I simply cannot do that. I also want to be able to look at myself in the mirror without guilt.

Cover crops have to work for the farmer, not the seed salesman.  There are several fantastic seedsmen out there and I do not want to disparage that fine profession.  I feed my family by being a seedsman and marketing seed. Most seedsmen are a trusted source of information and quality seed.

Questions I Get A Lot

The planting date question comes up a lot. For example:

  • How soon can a farmer plant cover crops after wheat has been harvested?
  • Can a farmer plant clovers into corn at “the last cultivation?” (even though only a few farmers still cultivate).
  • When is it too early to plant radishes?
  • When is it too late to plant radishes?

Money has not always been good in agriculture and I doubt that this current boom will last forever (it never did before).  So I want to give answers based on sound agronomic practices that will work 90% of the time.

Question: Can you plant crimson clover at “lay-by”?

Yes you can.  My granddad did that practice back in the 1950’s.  Of course he planted in 38″ rows with 16-18,000 plants per acre.  He did not use herbicides but he did cultivate.

However, how many of us farm like my granddad did?  A few of you might –  with good reason to do so (specialty corn or organic production).  But, can it work with modern herbicides and plant populations pushing 35,000 plants per acre?  Maybe, but not consistently – and probably not.

I think I tried to say “no” but I’m aware that some farmers have done it.  But, can we do a practice if it is not going to work 90+% of the time?  Not on a large scale.  Can we afford to try it on a few acres?  Maybe.

Here is a northeast Indiana farmer’s testimony of his success spreading crimson clover into his growing corn at sidedress time.  I am sharing this exactly as it was sent to me – trusting that it is accurate. I do not know the farmer who submitted the testimony.

I broadcast 10 lbs/acre of crimson clover at sidedress time this year. I seeded it on 6/6. We got essentially no rain from the first week of May until the last week of July. I figured the clover wouldn’t grow, but it laid there until we got rain and by harvest we had a nice stand. I’m not sure how this would work in a ‘normal’ year, but it sure worked good this year. I left some check strips and the clover didn’t affect the yield.   The seeder was just an old 12V spinner seeder I clamped onto our N toolbar. I’m attaching pictures of it and the clover stand. 

Photos provided are below.

My Observations

My guess is that this farmer used only glyphosate and no residual herbicide.  It was also terribly dry this summer and this seeding would have been more like a “dormant seeding”.

This was not at all typical for an Indiana summer. It was the driest July on record and June and August were also very dry.  Note how short the corn is in the photo with the corn head.  There was a lot of corn 3-5′ tall this year in Indiana.  I’d guess that a 5 foot height would cover the corn height in this field.  If the crimson would have been planted in a “normal” year I would be surprised if he would have had success like this.  But, boy, it sure is a beautiful stand in these photos!

If you try this practice, just experiment with a few acres to see what works on your farm.

Seeding Crimson Clover at “lay-by” in June in NW Indiana.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Note how short the corn is in the photo. Contrary to the belief of Illinois and Iowa farmers, this is not typical for NW Indiana corn! Most likely the rains that came in August were adequate to germinate the clover and there was plenty of sunlight getting to the ground so the seedlings had heat, moisture, and sunlight. What a beautiful cover crop!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Here is a beautiful stand of crimson clover between rows of harvested corn! Unfortunately the lack of corn fodder shows that the corn was under severe stress in 2012. While achieving a nice cover crop is important, I would prefer 200+ bushels/acre corn and a less advanced stand of clover at harvest time.

Question: Can you plant radishes right after wheat harvest?

No.

Even if you use an excellent radish,  it will bolt.  I don’t care which radish you use – it WILL BOLT if you plant it too early in the summer.

Bolting means that it will try to produce seed.  Generally a radish that bolts has a smaller and shorter tuber and most of the plant energy goes to seed production instead of root tuber production. If you wait until early August and use the proper radish you will see very little if any bolting.

I have been in several fields this fall that had no plants bolted.  I have also seen many fields that had a high percentage of plants that bolted.  Some claim that the exceptionally high soil temperatures in the summer of 2012 caused the August planted radishes to bolt.  That may be the case.  One thing I know for certain, if a radish is planted in July, it almost always bolts and can produce viable seed in the fall – and that could create potential problem for years to come.

Dave’s Best Advice

Wait until August to plant your cover crop radishes.  Use the few weeks between wheat harvest and planting cover crops to clean up weeds that were in the wheat field and also control volunteer wheat.  Patience is a great virtue.  It is important that you see an excellent return on your investments that we make in cover crop seed and seeding cost.  Our goal should not be “to be done first” but rather to have the best cover crop and healthiest soil.

I hate seeing fields like this as I know there was potential for seed to be produced and dropped to the soil possibly creating some issues in future years. Was this field planted too early or was the wrong radish planted? I do not know but I do know that farmers should chose wisely on planting time and what radish to plant.  Thankfully not every plant bolted so there are still plenty of plants “doing the radish thing” in the soil very well.

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.

Harvesting Cover Crops for Emergency Fall Forage

Need Feed?

Many producers across the Midwest and beyond have very poor corn. Grain and Silage yields will be significantly lower than normal in 2012.

Harvesting cover crops for emergency fall forage may be able to play a major role in lessening the impact of the 2012 drought disaster for livestock producers.  As I traveled from Indiana to eastern Iowa and through Wisconsin I saw dry ponds, cracked soil, nearly dead alfalfa, completely brown pastures, and an exceptionally poor corn crop.

I have received phone call after phone call from dairy and beef producers asking what cover crops they can use to provide food for their animals this fall and winter.  Below I have listed a variety of choices that may work well for producers needing feed (if we get rain).  By the way, these choices are also excellent cover crops.

Fall Forage Fast- Mechanically Harvested

Sudangrass or Sorghum X Sudangrass

BMR Sudangrass is a great choice for fall feed - IF you can get your hands on some this year.

Both of these would be choice 1-A and 1-B. However the producers in Texas have been experiencing drought for the past few years and seed supply is exceptionally tight.  Choose BMR varieties if you can find them.

Spring Oats/Spring Triticale

This photo was taken south of East Lansing, MI in April 2010 and shows Oats in the center with Cereal Rye to the left and Spring Triticale to the right.

This is not a “sexy” choice but it is a very good option.  Oats sown in July and August will out-produce all of the winter cereal grains if a fall harvest is desired.  I have worked with Ed Ballard from the University of Illinois and Gary Wilson from Ohio State University Extension for a number of years on summer seeding Oats and found great success almost every year.

Stan Smith from OSU Extension is a real believer in summer seeding oats as seen in this excellent article.  Seed the Oats at 2 bu/acre and fertilize with 50+ Units of N or manure equivalent.  Spring Triticale will behave very similarly to Oats when summer seeded.

Oats and Crimson Clover

From this photo of crimson clover, you can see the potential forage value planted with oats (note the field in the background).

I really like this mix because it will be higher quality than plain oats.  Plant the oats in the grain box and the crimson clover in the small seed box.  Plant the oats at 2 bu/acre and the crimson clover at 5-8#/acre.

Nathan Anderson of Cherokee, Iowa (NW Iowa) planted this mixture in 2011 and had very good success. While taking one cutting for hay and grazing 2 times in the fall/winter, he showed a profit of nearly $140/acre in beef production (weight gain) and hay produced.

Make sure that the crimson clover is inoculated and do not plant the crimson clover more than 1/2″ deep.

Oats and Cereal Rye (or Winter Triticale)

Oats (left) and Rye (right) planted in August show the value of Oats as a fall forage in this photo taken in October 2011 in NE Indiana.


Harvest the oats in the fall and the cereal rye in the spring.  I’d look at 2 bu/acre oats and 1 -1/2 bu/acre on the cereal winter rye or triticale.  Consider adding 5-8# of Crimson clover to this mix as well.

 

 

 

 

 

 

 

Oats (or Spring Triticale) and Peas (Forage or Austrian Winter Peas)

Austrian winter peas can produce A LOT of quality forage.

Plant a 50/50 mix of this combination for high quality fall forage.  Be sure to inoculate the peas.  Plant this mix 1 1/2 -2″ deep for best success.

 

 

Annual Ryegrass/Annual Ryegrass – Crimson Clover Mix or Italian Ryegrass

Annual ryegrass makes great fall and spring feed. It loves nitrogen, so apply plenty of manure. Add crimson clover to this, and WOW!

Annual Ryegrass or Italian Ryegrass will not produce the tonnage that the spring cereal grains will.  Ryegrass needs cooler temperatures, more moisture, and more fertility than the spring cereal grains need.  The main benefit is that you can get a very high quality forage…just not a lot of it unless you have the moisture, cooler temps, and higher fertility.  Maybe in the southern parts of the Midwest and further south this can be a good option.  Italian Ryegrass will not grow as aggressively in the fall as Annual Ryegrass will.

 

Spring or Winter Barley

Barley is a multipurpose cover crop that can be beneficial to hog, dairy, and beef producers.  It is a wonderful grain to use for feed and it is harvested for grain in June.  The haylage would be harvested in May with plenty of time to plant corn silage or Sudangrass.  Spring Barley planted in July/August will act like Oats and spring Triticale. Winter Barley will act more like cereal rye or winter Triticale.  Plant 2 bu/acre for grain production and 3 bu/acre for forage production.  Use less N than you would with Wheat or Ryegrass.

Spring or Winter Barley is also an option. Barley grain can be fed pretty similarly to corn and be harvested in June.

 

 

Cover Crop Turnips – A Good Choice Over Radishes?

Cover Crop Radishes or Turnips as a Cover Crop – or Both?

Cover crop radishes certainly receive a lot of press. I have researched them quite a bit over the past four years. On this blog alone I have over 20 posts about radishes. They are fun to take photos of, dig around in, research, and even play baseball with.

It is hard to pick up a publication that mentions cover crops and not read about radishes and their benefits.  Some industry and university cover crop research leaders like Steve Groff and Dr. Ray Wiel (University of Maryland) have researched radishes for over 10 years.You might say that cover crop radishes are the “Rock Star” of cover crop species these days.

What About Turnips?

The Oats are nearly 30" tall and the turnips are around 18" in this Oactober photo. The Cereal Rye was about 6" tall at this time. This mixture was planted in late August and the photo was taken Oct 22 - approximately 8 weeks after planting. My daughter Grace was the model..
The Oats are nearly 30″ tall and the turnips are around 18″ in this Oactober photo. The Cereal Rye was about 6″ tall at this time. This mixture was planted in late August and the photo was taken Oct 22 – approximately 8 weeks after planting. My daughter Grace was the model..

Why are turnips used as a cover crop so little compared to radishes? Are they the “ugly step-sister” of the Brassica family?

Let’s look at some of the benefits of turnips. Some newer varieties (Appin in particular) provide a bulb that is almost entirely in the soil and a deep root system (though a smaller bulb/tuber than the radish).

Benefits of Turnips

  • Turnips are very palatable for grazing cattle and sheep.
  • Most turnips survive the winter and hold onto nutrients into the spring (longer than radishes).
  • Turnips sequester nutrients in a similar fashion and amount as radishes (see data below).
  • Turnips are easy to kill in the spring.
  • Turnips do not have the odor problems that radishes have (therefore they can be planted more “safely” in areas closer to towns or neighbors).

“Problems” with Turnips

  • Not all turnips are created equal. The old purple top (or that type) turnip and even the tankard type turnips have very little of the bulb in the soil – thus less soil activity.
  • Most turnips survive the winter and then need to be killed in the spring. Yes this can also be a benefit.
  • The turnips “bolt” in the spring and want to produce seed. Kill them as early as possible.

    Turnips will overwinter in the spring. The turnips above flowered out in March 2012 in central Indiana. This is nearly 5 weeks before “normal”

Frequently Asked Questions

  1. If we mix turnips and radishes together, is that okay?  YES – for grazing or for just using as a cover crop.
  2. If we plant turnips instead of radishes is that okay?  Yes – just be aware of the differences and that the turnips will most likely survive the winter.
  3. What if we are just looking to graze and only care some about the cover crop?  Choose turnips.
These three brassica types were collected from a Loundonville, OH farm in the fall. Pasja Hybrid Brassica (L); GroundHog Cover Crop Radish (C); and Appin Turnip (R). Note the difference in tops versus tubers.

 

Nitrogen tested in Radishes/acre from Loudonville, OH dairy farm  averages 200 units of N (data collected November 2010)

Nitrogen tested in Appin Turnip/acre from Loudonville, OH dairy farm showed nearly 300 units of N (data collected November 2010)

The turnip tops had nearly 200 units of N/acre.  This was NOT scientific but it is instructive that turnips are an excellent scavenger of N.

Nutrient Scavenging Cover Crops – How much good are they doing? It depends.

Meet the Cover Crop Scavengers

Over the years I have worked with cover crops I have recommended that producers use “scavengers” like Annual Ryegrass, turnips, cereal rye,  winter barley, oats,  and cover crop radishes.  These cover crops do a very good job of capturing excess nitrogen and other nutrients and keeping them from reaching the ground water or running off with surface water.  When the nutrients are scavenged they are available for the subsequent crop.

Most of these scavengers are “luxury consumers” of nitrogen and a few of them are also “luxury consumers” of phosphorous.  These are ideal to use on land where manure is applied.  They also work very well when grown with a legume like crimson clover, hairy vetch, chickling vetch, and Austrian winter peas.

However, if  limited amounts of nitrogen are available how will these scavengers perform?

The answer: not as well.

My answer is subjective but based on observations that I will show you via some photos.

 

Observation 1

It is easy to see where the manure was knifed in in this field. But how much more N is being taken up where it is darker green? We'll be doing tissue tests soon to determine that.

The first observation is where hog manure was knifed in after wheat had been harvested. The photo shows that the cover crop (Annual ryegrass and Appin turnips) looks considerably darker where the manure had been applied.  We will soon be taking tissue samples to see what difference there is in the amount of N, P, and K are in the plants.  We also anticipate a future post showing a root pit view of the root growth difference (if any).
 
 
 
 

Observation 2

The "yellow" strips are pretty obvious in the cover crops in this seed corn field. It is not obvious where the corn rows were but I expect the lighter strips are above where the corn row had been.

The next observation comes from a seed corn field in north western Indiana near Demotte in Jasper county.  The main area of difference in N uptake is found where the male corn rows had been cut out this summer after the female rows had pollinated.  The difference is color was not as dramatic as it was in the previous situation but there was a clear difference in color and the amount of growth (considerably more developed) of the cover crop.
 
 
 
 

Observation 3

The left half of this photo had 35#/acre of N but had no legume to feed the radish. The right half of the photo shows the significant color and growth difference when radishes are grown with crimson clover (and the 35# N/acre).

The next field is near Edgerton in NW Ohio.  This field had three different applications being trialed.  One area had a crimson clover and GroundHog radish mixture, another area had an Austrian Winter Pea and GroundHog Radish mixture.  In between these mixtures was a strip of Tillage cover crop radishes with no legume but with around 35 units of nitrogen applied (the ~35 # of N was applied across the whole field).  If you attend many cover crop meetings you will hear speakers tell you to apply 35-50 units of N on radishes if they are sown without a legume or without manure applied.  After seeing this field I believe we are underestimating what kind of N we need to apply for “best” results as the radish only strip had considerably smaller radishes with much less tuber growth and more “yellow leaf”.    The area with the crimson clover/GroundHog Radish Mix was by far the darkest green and had the largest radish growth.  However, even though the peas did not look as impressive as the crimson clover, the radish growth was significant and much darker green than the radish area grown without any legume.

Observation 4

Not only does the crimson clover add nitrogen to the soil it also greatly enhances the soil structure. The soil on the left came from where there was only radishes planted. The soil on the right had crimson clover and radishes mixed together.

Another observation from this field was that where the radishes were grown with the crimson clover the soil had a much improved structure over the soil where only radishes were grown.  The massive amounts of crimson clover roots (with an exceptional amount of nodules on them by the way) gave the soil a much better texture.  See a very descriptive video here.  These soils are “Williams County Clays” or “NW Ohio clays” and are well known for their tightness and poor drainage.  As the farmer Ryan Sanders said after seeing the results of this experiment… “I will never plant radishes alone again.”

 

Cover Crop Field Day Set at Robison Farms

CISCO Seeds, Robison Farms, and Dougherty Fertilizer are sponsoring a Cover Crop Field Day and Root Dig at the Greenwood, Indiana farm. If you’ve not had an opportunity to see cover crops in a real life farm setting, this will be a great meeting for you . There will be multiple species available to look at and expert agronomists on hand to answer questions.

 

When:

Wednesday, November 30, 2011 from 2-4 P.M.

Location:

Corner of Five Point Road (300 East) and Main Street (Rocklane Road) east of Greenwood, IN

Contact:

If you have questions or need further information contact  Don Robison at donrobison@ciscoseeds.com or 317-357-7013

  • Rain or shine we will have a gathering (call if the weather is bad for “plan B”)

 

Cover Crop Field Day Highlights

Come see ten different mixes and/or species of cover crops in a large plot setting.
  • 1100’ lineal feet of cover crop plots
  • 10 different mixes or straight species shown
  • guaranteed weather! (not saying what kind)
  • working with NRCS, SWCD, and Dougherty Fertilizer
  • root digs (weather contingent)
  • Cover Crop Agronomists on hand for tours and Q/A sessions
  • See over 150 acres of various Cover Crops withing 1/2 mile of plots

 

Purpose of the cover crop field day

To see different species of cover crops in a real to life situation. This was a soybean field that had the cover crops applied over the top of the standing crop at roughly 50% leaf drop.

 

Species You Will See

 

  • Radishes
  • Turnips
  • Crimson Clover
  • Oats
  • Winter Rye
  • Annual Ryegrass
  • Austrian Winter Peas
  • Several Mixes including the above species

 

 

 

Directions:

From Indianapolis

  • Take I-65 South to Exit 99. Turn Left at end of ramp and travel 1.5 miles east to the plots

From Louisville

  • Take I-65 North to Exit 99. Turn Right at end of ramp and travel 1.5 miles east to the plots

From Columbus, OH

  • Take I-70 West to Indianapolis, follow 465 South to I-65 South to Exit 99. Turn Left at end of ramp and travel 1.5 miles east to the plots

From Terre Haute

  • Take I-70 East to Indianapolis, follow 465 South to I-65 South to Exit 99. Turn Left at end of ramp and travel 1.5 miles east to the plots

 

Just down the road we plan on digging another pit where Annual Ryegrass and Appin Turnips were applied after hog manure was knifed in after wheat.

Cover Crop Radish Research reveals interesting data and information

In the summer of 2010 I entered a number of “cover crop” radishes into research plots in Michigan and Minnesota.  Some of the products I entered were given to me from a supplier in Oregon. They had collected seed samples from Europe that had been touted as cover crop worthy.  They weren’t. Fortunately those varieties never hit the US market – that I am aware of.

I also entered two other radishes that actually performed very well.  What we found is that not all cover crop radishes are created equal.  While many of the top selling radishes grew the way you would hope, there were some that did not perform well at all.

Here’s what I mean: The “lesser performers” either bolted and went to seed production early, or they had very small tubers, or both.

Now in the summer of 2011 we have planted new plots in MI and MN along with some plots in my garden “agronomy plot” in Winona Lake, IN (NE IN).  I planted my plots WAY too thick as it was very dry and I was hoping to get emergence.  I watered two times after planting the plot and that helped quite a bit.  Over the last week we received nearly 5 inches of rain, so I have a very thick, robust radish stand.

What I am seeing after 6+ weeks of growth is interesting.  I purposely planted the “wild looking radish” (“VNS Daikon Radish” on the tag) that was sold out of North Dakota in the summer of 2010 so I could compare it to Oregon grown VNS Radish.  I included two named products, GroundHog and SoilBuster (a mixture of two varieties) in the plot as well.  On the GroundHog I entered seed from two different years 2009 and 2010 to check for consistency (GroundHog is actually a true single variety of radish).

VNS stand for "Variety Not Stated" and in some cases "Buyer Beware." The Oregon grown VNS Daikon Radish is a far superior radish for cover crops than the VNS Daikon Radish from North Dakota.

I have a few early observations on these 6+ week old radishes (planted August 19, photos taken Oct 6):

  • The GroundHog from both seed crop years look the same (green top on tuber, similar tuber type and size).
  • The Oregon grown “VNS Daikon Radish” is far better than the North Dakota grown “VNS Daikon Radish” (seed purchased from the Pulse Group).
  • The North Dakota grown “VNS Daikon Radish” looks like it did in 2010 – already bolting (it started bolting at 4 weeks) and very little root.
  • The Oregon Grown “VNS Daikon Radish”  has shorter top growth than both GroundHog and SoilBuster.
  • The Oregon Grown “VNS Daikon Radish”  has smaller tubers than both GroundHog and SoilBuster.
  • GroundHog had more top growth than SoilBuster.

My conclusion so far:

The two named radishes (that are actually varieties) seem to actually show more “value” (more top growth and larger tubers) than either of the VNS products.  What does that mean to producers?  That maybe the few extra dollars you pay per acre is actually money well spent.

Both named products showed larger tubers and more top growth than the Oregon Grown VNS Daikon Radishes.

 

 

 

 

 

 

 

 

 

 

The tag from the North Dakota VNS Radish. Notice the "ND" under origin in the upper right. Click on the image to make it larger.