Plant Cover Crops

Learning about the benefits of planting cover crops.

Cover Crops and Earthworms

Cover Crop Root Pits Reveal Plenty

During the first week of April I was in several root pits in northwest Indiana and boy did we find plenty of interesting factoids! I was assisted by Eileen Kladivko from Purdue University on one day and Barry Fisher, Indiana NRCS State Agronomist, on another day.

What We Found in the Cover Crop Root Pits

We found several night crawlers and smaller worms as well in each pit we were in
  • Earthworms galore, especially where we had radishes and/or crimson clover. But the earthworms were plentiful in all cover crop species.
  • Earthworm channels 48″ deep in a field that had been long term no-till with one year of cover crop annual ryegrass/radish mix (planted after soybeans).
  • Roots from two different  crops in the same root zone/earthworm channel (soybeans and cover crop roots) over 30″ deep.
  • Earthworm eggs where radishes had decayed.
  • Soybean nodules 26″ deep on roots that went 44″ deep (long term no-till field – 10 years).
  • Annual ryegrass roots that were not as deep following corn as they were following soybeans (less N available for them to grow as vigorously).
  • Canola or oilseed rape in fields where bin run oats had been planted instead of seed oats.
  • Continued evidence of compaction. One year of cover crops does not eliminate all compaction issues (though roots from cover crops did penetrate through the compaction).
  • Radish and radish roots that were 34″ deep last fall were found at 40″ deep this spring (though dead).
  • Living radishes. Several radishes survived the Indiana winter (very mild winter), especially where they were protected by crimson clover and annual ryegrass.
  • 20 earthworm channels and 5 earthworms in an area 8″ by 8″ square at 6 inches deep (in a mixture of annual ryegrass, crimson clover, and cover crop radishes).
  • 700 acres of oats and radishes looking very different in the spring than it did in the fall!  (Click the links to see the different videos)

Miscellaneous Notes from the Cover Crop Root Pits

The farmer from our first cover crop root pit dig on April 4th reported that he saw less visible drought stress where they had long term no-till and cover crops, attributing the healthier plants to increased root depth.

We saw several fields of cereal rye after corn stalks being grazed by beef cattle.

Barry Fisher encouraged everyone to “expand your farm vertically.” In other words, don’t just keep buying/renting more land. Instead, put cover crop roots down deeper to create better land where you farm – and get more yield.

Be sure to control your annual ryegrass instead of waiting on the crimson clover to grow taller.  Much of the ryegrass was 10-12″ tall with the crimson clover at 6-8″ tall.

Farmers are becoming more creative with cover crop applications and types, and they are finding success – not surprising!

 

Other than the "extra goodies" from the VNS oats, this field was ready to plant without herbicide in the spring.
We saw several fields where cattle were grazing cereal rye planted into corn stalks.
Cereal rye in one row and crimson clover and Appin turnips in the other row (mixed together).

 

One of the joys of working with farmers is the excitement I see on their faces when they "get it" about soil health. There were several excited farmers again this spring.
We found several earthworm eggs around the decayed radish holes.
We found roots from soybeans and annual ryegrass in the same root zone/earthworm channel.

Cover crops for gardens – and my wife, the cover cropping queen!

My wife Sally must love me…or at least she is observant to see how cover crops are improving the soil in our family gardens.  Over the nearly 19 years we have lived in our home we have had a garden where we often have raised vegetables for the Hispanic families that we minister to.  A few years ago we had nearly 50 chili plants of various types (Jalapeno, Serrano, Habanero, etc…) and we raised several bountiful crops.  But we found that after raising these crops that we had few if any earthworms and our soil was becoming more compacted year after year.  We decided to put the gardening on hold in some plots as we look to improve our soil.  Just as last year, Sally planted different cover crops in August into some garden plots.  I need to explain, these plots are in the front of our house…right near the road!  My wife is a pretty bold cover crop user (and a good advertiser as well).

This Austrian Winter pea and cover crop radish mix fill one garden patch.

Why would she plant cover crops in our gardens?  The main reasons are to enhance the soil quality with earthworms and to reduce soil compaction.    Sally is a pretty “eco-friendly” gal as she recycles everything and she knows the value of taking care of the soil.  What we have found in the past 12 months is an increase in our earthworm population and several more roots in the soil to help build organic matter.  I expect that we will have some veggies in these garden plots next year.  I’m confident that Sally is doing the right thing by improving our soils…even if it is only a few square feet at a time!

 

A mixture of turnips, cover crop radish, and crimson clover is helping build the soil in my wife's garden plots.
The front of the Robison "Agronomy farm" house in Winona Lake, IN. Note that Sally let's me have a "Cliveden pasture green" house too! It must be love!

 

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.

66″ No-Till Corn Roots Following Cover Crops

This is not a scene from a horror flick...it's a scene from Frank Gibb's experiment showing that smoke was coming up from the tile drains over 200 feet from the tile entry point.

I had a “see it to believe it” moment in late August near Stryker, Ohio (Williams County – NW Ohio).  A very long and deep root pit had been dug as Frank Gibbs (Ohio NRCS Resource Soil Scientist) was looking for the tile in a continuous no-till corn field.  I’m thankful that the tile was not easily found because we found pretty remarkable “things” going on in the soil beneath the soil.  What were those “things” we found?

Watch the Frank Gibbs video to see how special cover crops and no-till make a tough soil a healthy soil!  Frank does some pretty incredible work that shows the value of having a healthy soil.  Now, watch this second video of the smoke test results.  I have seen this test three times and NEVER seen it this awesome!

  • corn roots and earthworm channels up to 5 1/2 feet deep on no-till corn
  • top soil approximately 3 feet deep on top of lake bed soil
  • smoke from Frank’s “smoke test” coming up from 34″ deep over 200 feet away from the entry point

Frank says in the video that often times that the corn roots would “be turning out” when they hit the lake bed soil.  But because of cover crops and no-till the earthworms had plenty to eat for much of the year and the soil was very healthy compared to similar soil types in NW Ohio.  Obviously these roots did not “turn out”…they kept going down all the way to over 5 feet deep!

 

Crimson Clover; a jewel among the cover crop legumes

bee on crimson clover
Crimson clover is a top nitrogen producer and beautiful as well.

Crimson clover is a real jewel among the cover crop species.  Crimson clover is an excellent producer of nitrogen and there are some newer varieties on the market that are very winterhardy even into Michigan.  Dr. Eileen Kladivko measured how much nitrogen was produced by crimson clover in a test plot in western Indiana.  What she found was quite amazing!  After around 90 days the crimson clover had produced over 140# of nitrogen per acre!  Now, this was a limited test of one plot but the best of the other plots came in at just over 50# N produced.  That is a significant amount of nitrogen.

Crimson clover mixes very well with annual ryegrass (to help the ryegrass be healthier and growing better when there is no manure applied).  It also mixes well with cover crop radishes and or turnips.  Crimson clover is generally considered more shade tolerant so it works well aerial applied into standing corn.

Crimson clover MUST be inoculated for best success.

I have listed some advantages and disadvantages below:

Advantages of Crimson Clover:

  • There are some excellent new varieties on the market that are more winterhardy.
  • There are earlier maturing varieties that mature early enough to make more N in the spring before killing.
  • At around 90 days after wheat it can produce upwards towards 140 units of nitrogen.
  • Earthworms love the environment around the roots of crimson clover…it’s creates “earthworm heaven!”
  • It is easy to kill in the spring.

Disadvantages of Crimson Clover:

  • VNS and MOST older varieties will probably not survive the winter in the Midwest.
  • It has some hard seed so you may see some coming up some months after planting.
  • If it is a very late wet spring there is a slight chance the clover will re-seed itself.

Crimson in ARg
Crimson clover mixed with annual ryegrass is a great cover crop combination.
Crimsom roots
Properly inoculated crimson clover produces large and multiple nodules. Note the root hairs as well.

Earthworms…valuable resource on farm ground

Earthworms are exceptionally valuable builders of  healthy, fertile topsoil.  Jill Clapperton stated that a good sign of a healthy topsoil was that a “shovel-full of soil” should have 8 earthworms in it.  In my  field diggings I have found anywhere from ZERO to 10 erathworms per shovel-full.  I found 10 in crimson clover, 8 in annual ryegrass, 7 in my Austrian winter peas, 10 in my annual ryegrass/crimson clover mix and ZERO where I had no cover crop.
Earthworms thrive in many cover crops
Earthworms thrive in many cover crops

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