Plant Cover Crops

Learning about the benefits of planting cover crops.

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 to the Rescue!

A Huge Problem

Brad, TJ, and Andrew inspecting on of Brads many cover crop fields that were planted in July 2013.on prevented planting acres.
Brad, TJ, and Andrew inspecting one of Brads many cover crop fields that were planted in July 2013 on prevented planting acres.

Recently I was in Minnesota with Brad Hagen, T.J. Kartes, and Andrew Heath looking at Brad’s 1,000+ acres or cover crops.  Brad had not intended on planting any of theses acres to cover crops in July, 2013…his intentions were to plant them in August or early September.  But spring 2013 rains and floods kept Brad from planting corn or soybeans on most of his 1,700 acres near Ellendale, MN (about an hour SW of Rochester, MN ).  Brad attended a cover crop meeting TJ set up for me to speak at on behalf of Legacy Seeds last March and as I spoke I could see Brad’s mind working.  When the spring rains came so did phone calls from Brad to TJ and from TJ to Andrew or me (or both)…”what can I do to build soil during this disaster?” was the theme of the weekly (if not daily) phone conversations.

You can seemingly look for miles without seeing a cash crop planted in some areas of SE Minnesota
You can seemingly look for miles without seeing a cash crop planted in some areas of SE Minnesota

Cover Crops to the Rescue!

Brad’s goals are to build soil and to scavenge nitrogen from his hog operation and build nitrogen with legumes.  Realizing that we would plant in early-mid July and not in mid-late August we all understood that we did not want to have to mow to remove seed heads if at all possible – so we left Radishes out of the mix.  We also realized that we wanted to use a “summer” clover, so we used Berseem Clover for it’s excellent growth and N producing ability.  We chose Oats as the grass in most fields and then we added a twist, Pasja or Vivant Hybrid Brassica.  I have worked with Pasja for over 10 years and rarely ever saw it produce a seed head in the summer or fall.  While Pasja (nor Vivant) have a big tuber like a Radish they do have the ability to scavenge a tremendous amount of nitrogen and earthworms dwell around their roots.

Brad Hagen looking at his Pasja Hybrid Brassica and Berseem clover. These are brand new species to Brad.
Brad Hagen looking at his Pasja Hybrid Brassica and Berseem clover. These are brand new species to Brad.  This field was planted 10 days before the photo was taken.

In some later July (and soon to be mid-August) planted fields we chose to use Spring Barley and Crimson Clover along with PileDriver Radishes and Appin Turnips.  TJ and Brad requested this mix so we’d get later fall growth, deeper penetration through compacted soils (Radish vs. Pasja/Vivant) and excellent N production from the Crimson clover.  Spring Barley was available and many folks in Kentucky have told me that barley makes the soil “sweet” (whatever that means).  From experience I know that soil after Barley is quite mellow.

Early August Report

From what I saw on August 1 I was very impressed!  As other folks in the region were planting straight Oats or possibly a few were adding Radishes very few other folks seemed to totally share Brad’s goals.  Brad told me that he is doing these cover crops because he wants to build his soil and because he wants his 7 year old son to have better soil to farm when he grows up and farms his place like Brad does with his father.  I’ll have more photos in a month or so.  I believe Andrew, Brad and TJ will plan a field day for September.  It’s beautiful country near the Hagen farm…it probably will be worth the drive in September to meet Brad and his family.  They’re pretty special folks…

Take a look at my You Tube channel “covercropdave” to watch an interview I have with Brad and TJ.

This beautiful stand of cover crops was planted July 2, 2013 at Brad's dad's place not far from the hog barns. If you sniff this photo real hard you can smell the hogs!
This beautiful stand of cover crops was planted July 2, 2013 at Brad’s dad’s place not far from the hog barns. If you sniff this photo real hard you can smell the hogs!

 

 

 

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.

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?

 

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.