Plant Cover Crops

Learning about the benefits of planting cover crops.

Crimson Clover

Prevented Planting Row Crop Acres – Which Cover Crops Can Help?

The following was originally posted on May 27, 2011 when the Eastern Corn Belt was suffering with severe flooding and wet conditions.  In 2013 the Upper Midwest – especially Iowa, Minnesota, and Wisconsin – is flooded and wet.  Many farmers are considering taking the crop insurance for prevented planting.  Even if it would stop raining – which does not appear will happen anytime soon – many farmers will not be in their fields for two weeks.  While locations are different, the recommendations below still apply.  Please keep the farmers in the Upper Midwest in your prayers; they need it!

For other options that might include growing cover crops for forages click here.

More rain tonight on already flooded fields create a tough situation for many Midwestern farmers.
More rain tonight on already flooded fields create a tough situation for many Midwestern farmers.

In 2010 there were wet spots in fields that were never planted,  so some ingenious farmers planted cover crops in those spots after they dried out.  Now in 2011 there are several entire fields that may not be planted to cash crops at all.  I have heard from two friends in Ohio that are working on plans to help northwest Ohio farmers know what to use on their prevented acres.

Maybe this is not an issue where you live.  I hope you never have to face a spring like this year in the Eastern Corn Belt, where many producers in Ohio, Indiana, Illinois, and Michigan are struggling to get their crops in the ground.  The forecast is for many more days of rain to finish out the month of May.

For wet spots in fields there are many good options like these cover crop radishes that were planted later in the season in a field of sweet corn.

For prevented planting the cover crops may not be harvested until after November 1st.

So what are the options for planting cover crops in the prevented planted fields?  Below I will list the options with a few of their benefits and also some disadvantages.

Oats

Advantages

  1. Provides erosion control
  2. Scavenges nitrogen
  3. Grows a deep and fibrous root mass
  4. Promotes mycorrhiza growth
  5. Quick to establish
  6. Relatively inexpensive
  7. Can be broadcast and lightly tilled in
  8. Can be added to other cover crops to add additional value
  9. Can spray with broadleaf herbicides if necessary to control weeds

Disadvantages

  1. While they provide cover and decent root growth they do not provide additional nitrogen to the soil (at the most it would be very minimal)
  2. Best to use seed oats vs. bin run oats for optimum value
  3. If planting wheat after oats there may be some “grass after grass” issues (I’m not confident this will be a problem and would welcome comments)

 

Field Peas or Austrian Winter Peas

Austrian Winter Peas and cover crop radishes were planted into prevented planting acres in Michigan in 2010. These peas were producing nitrogen for the 2011 crop while fields that were sprayed or tilled for weed control had no such benefit.

Advantages

  1. Can provide 60-120 # nitrogen/acre (excellent if following with wheat in the fall)
  2. Can be broadcast and lightly tilled in (1″ or deeper)
  3. Can be added to other cover crops to add additional value (add to oats)
  4. Can spray with broadleaf herbicides if necessary to control weeds

Disadvantages

  1. Slower to establish than oats
  2. More costly than straight oats
  3. Seed MUST be inoculated at the time of planting

 

Crimson Clover

Advantages

  1. Can produce up to 150# N/acre within 100 days (great option if following with fall planted wheat or Winter Barley)
  2. Fairly quick to establish
  3. Relatively inexpensive
  4. Can be broadcast and lightly tilled in (1/4-1/2 inch deep)
  5. Can be added to other cover crops to add additional value (add oats at 1 bu/acre)
  6. Can spray with broadleaf herbicides if necessary to control weeds (This article is for seed production in the northwestern part of the USA)

Disadvantages

  1. More costly than straight oats
  2. Slower to establish than straight oats
  3. Seed MUST be inoculated (it may be purchased pre-inoculated)

 

Cowpea

Advantages

  1. Can produce 60-150# nitrogen/acre
  2. Can be broadcast and lightly tilled in (1″ or deeper)
  3. Can be added to other cover crops to add additional value (add to oats)
  4. Can spray with broadleaf herbicides if necessary to control weeds

Disadvantages

  1. Cost and availability of seed
  2. Slower to establish than oats
  3. Seed MUST be inoculated

Other crops to consider: Berseem Clover, Fava Beans, and others.

For further information, please read this excellent article by Barry Fisher, NRCS Agronomist from Indiana, who wrote on this very topic in 2009.

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!

 

Photo diary- Corn after a cover crop (after corn)

“Planting this corn field was like planting into a garden” said my friend Dave.   He has been a ‘cover cropper” for six years now.  This year Dave no-tilled approximately 50% of his acres.  Dave is one of the most innovative guys I know…but he’s also “cautious”; he does not want to lose money!  That’s why Dave loves cover crops…using cover crops he has improved his profitability.  In this photo diary we will look at photos from April, May and June where Dave had a cover crop consisting of Oats/GroundHog Cover Crop Radish/AU Robin Crimson Clover.  The previous crop was corn.

An April view of the field with the AU Robin Crimson clover that over wintered. The oats and GroundHog Radishes had died out over the winter as expected.

 

A May photo of Crimson Clover that could not be killed yet because the field (and all other fields in the area) was too wet to spray. Normally by the date the photo was taken the Crimson Clover would have been dead and the corn would have been planted.

 

No-Till Corn on Corn planted into Oats and AU Robin Crimmson Clover

What if a cover crop dies over the winter…was it still valuable?

As I take phone calls and conduct meetings I ask producers if they want to have the cover crop they are choosing to overwinter or die during the winter.  I’d guess that the answer as split 50/50. The biggest reason for wanting the cover crop to die is that producers don’t want to have “to mess” with killing a crop in the spring of the year.  Other advantages that folks mention is that they believe that the soil will be warmer if there is not a living cover in the field.

This mixture was planted on time but had very little moisture in the fall of 2010. All things considered it is a beautiful stand. However, the crimson clover is so short that I hope that it overwinters so the producer can get "maximum" nitrogen benefit for the 2011 corn crop.
On November 17, 2010 we found annual ryegrass roots 40" deep after just 10 weeks of growth. We want this field to overwinter...but we already have accomplished nutrient management goals by holding nutrients from the manure applications. If the field overwinters I believe we may find roots 70" deep when we dig in April 2011.

Advantages of having a “short-term summer/fall cover crop” is that you should still control the majority of the winter annual weeds, many legumes will still produce a good amount of nitrogen before winter (Austrian Winter Peas, Cowpeas, Crimson Clover, Berseem Clover, Field Peas, etc…).  Radishes and turnips will do their nutrient scavenging and plow pan cracking work before the killing freeze too. Even annual ryegrass might have produced a pretty good root system before it goes winter dormant (or dies) depending on the seeding date/fall growth. (See  details of what we found in an annual ryegrass field in the fall of 2010.)

So what would be the advantage of a winterhardy cover crop?  Improved spring erosion control, more living roots in the soil for a longer time period, more spring-time earthworm activity, more nitrogen produced (from legumes) and over a longer time period, minimal soil temperature change (versus a dead cover crop or no cover), a longer grazing time period, to name a few.

Disadvantages of the crop overwintering would include the risk of a very wet spring causing trouble getting the crop killed, possibly cooler spring soil temperatures, and possibly some reasons that don’t come to mind.

If using a legume like clover it seems to be advantageous to have it overwinter, however Berseem clover possibly produces the most N of any legume…and it is sure to winterkill in Midwestern winters.  And I like Berseem clover when it fits the producers situation.

So, does it matter if the cover crop survives the winter…even if it dies when you expected it to survive?  My answer is that there are still benefits on most cover crops IF they were productive in the fall/winter.  If you have a late planted cover crop that has minimal growth in the fall and then it dies…you possibly “wasted” money.  Do your best to plant cover crops in a timely fashion.  Give them the best opportunity to do their best!

Cover Crop plots in December-What can we tell now? part 2

In this post we look at two more videos of mixes on December 2, 2010.  This first mix in this session is of Austrian Winter Peas and GroundHog Radishes.  The seeding rate is 30# Peas and 5# of Radish per acre.  The main thing we observe in this plot is the larger radishes than we saw with the mixes of annual ryegrass, crimson clover and radishes.  Now, in this mix there are more radishes than in the previous two plots (see previous post).  So we have 2-3#/acre more radishes yet larger radishes.  Again, this is NOT scientific, but it sure appears that the radishes, which are luxury consumers of nitrogen, are much larger…thus I conclude, have been fed more  nitrogen from the peas.  It was quite surprising to me to see how much the peas have grown sine I last saw the plot in early November.  The cooler weather seemed to really allow them to grow at a faster pace.

In the second video on this you will see the plot that appears to have the most nitrogen produced.  This mixture is of 17#/acre of AU Robin Crimson Clover and 5#/acre of GroundHog Radish.  In this plot the radishes are noticeably larger in girth and above ground growth.  In fact as you look across the plot it is obvious that this plot is the most “robust” in its growth. In the spring of 2011 I anticipate that the AU Robin Crimson Clover will still be producing more nitrogen.  From previous cover crop field pits we have dug this fall we have found roots on the crimson clover at 24″ deep.  So we have deep rooted cover crops with both items in this mixture as well.

In both of these plots you have excellent nitrogen production and nutrient scavenging!  Personally I like that for a cover crop.  What do you like?