Plant Cover Crops

Learning about the benefits of planting cover crops.

earthworms

Fertilizing Cover Crops & Planting Legumes After Soybeans

If you spend any time at all in cover crop meetings, you may have heard that it’s a good idea to add 20-50# of Nitrogen per acre to your cover crop – if you don’t have a legume in the mix or you don’t have manure available. You also probably heard (or participated in) the grumbling that predictably starts from the crowd. Who wants to fertilize a crop that they will not harvest?

While it’s true that producers will not “harvest” the cover crops, they will have healthier cover crops which should lead to healthier soils and healthier profits.

Manure as the No-Brainer

Obviously if manure is available it is a smart move to put manure where you will have or already have cover crops.  We know from research that cover crops can hold as much as 90% of the nutrients from manure applications.

We have also know that where manure is applied without a cover crop being present (even if worked in) we can lose a significant amount of nutrients into ground water or as surface run-off.

What About Adding Commercial Fertilizer?

The Radishes on the left had manure applied and those on the right did not have any additional nitrogen applied.
The Radishes on the left had manure applied and those on the right did not have any additional nitrogen applied.

But, what if there is no manure to apply and for some reason you do not want to include a legume in your system?

Is it worth applying 50# of nitrogen to produce a cover crop?

Let’s look at what we think we know:

  • Pages 22-24 of Managing Cover Crops Profitably provide formulas to figure out the value of using cover crops as a green manure in a cover crop system –  whether with legumes, manure, or fertilized.

Look especially at the section on “Potential losses” to see that there can be nitrogen losses even in this scenario.

  • Cover crop experts say to count on 50% of the N captured or N produced by a cover crop to be available to the next cash crop.
  • It appears that adding a grass with legumes or brassicas will help “slow down” the release of the N in the spring making it more slowly released to the next crop.

 

Here is a photo of the Ingham County Michigan Cover Crop Plot. Where there was a legume in the mixture there was considerably more growth and earthworm activity
Here is a photo of the Ingham County Michigan Cover Crop Plot. Where there was a legume in the mixture there was considerably more growth and earthworm activity

What can we expect if we plant a cover crop and we don’t add more nitrogen?

How will that cover crop do?

I will utilize work that Dan Hudson did when he was an Extension educator in Ingham County Michigan in cover crop plots he planted back three or four years ago.

  • Radish tubers are considerably smaller and the roots appear to not be as deep  (I have not dug a root pit in this scenario).
  • Grasses have a more shallow root system in forage settings when fertility is lacking.
  • The cover crops were pale green.
  • The “hungry” grass cover crops had less earthworm activity than in the grass + legume mix plots.
  • “Hungry” radishes and turnips had much less tuber and top growth, thus sequestering less nutrients (one of their main functions).
  • Winterhardiness on cover crops is potentially not as good when the cover crop is undernourished.

What can we expect after soybeans?

Do we need a legume in the cover crop mix following the beans or is having a grass and/or brassica to sequester the N from the soybeans good enough?

Let’s investigate the difference between adding a legume to a cover crop mix following soybeans compared to planting scavengers only.  The charts are from our family farm trials.  The charts show the chlorophyll readings of the corn in the year following the soybeans (and then following a cover crop).

It is important to look at the “Y” axis as each chart is slightly different in how it shows the top reading.

When Austrian Winter Peas were added to a scavenger (Radishes) the chlorophyll readings were very favorable compared to the no cover crop check plot and plots with just scavengers.
When Austrian Winter Peas were added to a scavenger (Radishes) the chlorophyll readings were very favorable compared to the no cover crop check plot and plots with just scavengers.
Just like the peas gave us an advantage over the no cover crop check the crimson clover showed very favorably.
Just like the peas gave us an advantage over the no cover crop check  and scavengers, the crimson clover also showed very favorably.

 

While the Oats and Radish showed exceptionally favorable in the early part of the season the plot are "ran out of gas" as the corn was pollinating.
While the Oats and Radish showed exceptionally favorable in the early part of the season the plot “ran out of gas” as the season progressed.
Straight Winter Cereal Rye was impressive early season but also did not fare as well against the check as the mixes with legumes
Straight Winter Cereal Rye was impressive early season but also did not fare as well against the check as the mixes with legumes.

As we looked at the yield of the corn in these plots we saw a considerable difference – suggesting that even after soybeans we might want to add a legume to improve the corn yield the following year.

Yields from the different cover crop plots shown above were:

Check Plot                                    105.24 bu/ac

Winter Cereal Rye                      126.86 bu/ac

Oats and Radish                          138.79 bu/ac

Crimson Clover + Radish           153.99 bu/ac

AW Peas + Radish                        164.82 bu/ac

Conclusion

All indicators seem to point that adding manure, a legume, or additional N might very well pay off when planting a cover crop, even after soybeans.  However, adding a nitrogen source is not necessarily vital to having a successful cover crop system.  I would suggest that you try different scenarios on your own farm and in your own system and see what works best for you.

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 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 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.