Plant Cover Crops

Learning about the benefits of planting cover crops.

Winterhardiness

Farmer Report from Ohio – Planting into “Out of Control” Peas

The cover crop radishes varied in size with the amount of moisture in the field in the fall of 2010.

My good friend David from Mercer County, Ohio is a great cover crop advocate.  Over the past few years he and his father-in-law have begun planting cover crops after their wheat crop is harvested.  The first year he planted oats and cover crop radish and this past year they planted a mixture called N-Vest® Groundbreaker Mix (a mixture of Austrian winter peas and cover crop radishes).  The summer of 2010 set some records for being exceptionally dry.  Neither the peas nor radish grew the way anyone hoped for, but David did find radish roots around 20 inches deep.  The peas were less than spectacular but still acceptable for as dry as it was.

No-tilling corn into this mix of peas and wheat looked like an easy task in early May when this photograph was taken...but the rains kept coming!
This is not what was expected! Early June 2011 was wet and the peas were tall.

As I have reported in several previous posts, the weather in NW Ohio and the Eastern Corn Belt was the wettest in 120 plus years of keeping records.  The Austrian winter peas and volunteer wheat over-wintered.  In early May David was convinced that they would no-till directly into that “mix.”  But the rain came and came often! By early June the peas had grown quite a bit, like up to four feet tall…and that is what they no-tilled into.  Actually, David said it was the “most mellow soil” he planted into all spring.

Just a few days after planting David sent me the photos of a beautiful stand of corn where the peas had been over 4 feet tall.
Three weeks after planting the corn looked great and the cover crop was dead. This photo was taken June 21, 2011.

I joke that David was nearly written out of the family will when he started no-till planting his corn!  The neighbors were all watching but David persevered and kept planting…even though it was not as easy or as early as he hoped it would be.  A few days later David e-mailed me more photos…and then a week later more photos…

Exactly four weeks after planting and the corn looks remarkable.

So now the neighbors are wondering about this David “kid” that married into this operation.  Maybe he is not as foolish as they thought earlier in the spring!  Exactly four weeks after planting the corn was over “knee high by the 4th of July” and now the neighbors are asking what that cover crop was!

In mid-July, six weeks after planting and the weather has been HOT and dry...but according to David, the field "shows less stress" than conventionally tilled field that had no cover crops.

But the dry summer of 2010 was now being duplicated by another dry summer and the summer of 2011 has been much hotter than 2010.  So how has the no-till corn fared during these challenging conditions? Very well, actually.

There was less than 2" of rain in a very hot July and yet the field looks quite good considering the heat and dryness that it has experienced.

So will David plant cover crops again?  Yes!  In fact they are already in the ground and waiting for rain to emerge.  David has been very excited all the way through this process as he has been confident he is doing the right thing for his soil and the future of his farming operation.  Thanks to David for providing the photos and information to encourage all of us that cover crops are an exciting option that we should all consider.

Cover Crops Under the Snow – What’s Happening?

A blanket of 12" of snow covered my cover crop plots on Feb 12, 2011. What would I find??

Across much of the Corn Belt there has been pretty good snow cover since the beginning of 2011.  On February 12, 2011 it was not snowing in my hometown of Winona Lake, IN so I decided to take out the snow shovel and dig in my cover crop plots to see what was going on.  On February 10, the real temperature was down to -11 degrees F and we’d had quite a bit of wind as well the past few weeks – so I didn’t know what to expect.  I know that snow is a great insulator but we’ve been cold the past 6 weeks.

I was VERY pleased to see green as I dug through the 12″ deep blanket.  I also took my spade out to the plots and decided I’d try to dig if the ground was not too frozen.  What a great idea!  I did not try to dig beyond 10″ but I found plenty of roots and even signs of mychorrizia growth. My plots had been planted late into exceptionally dry soil.

So was it “worth it” to get some cover crop growth?  I’d suggest the answer is “YES” as I have LIFE in my soils in February and not the typical “nothing” going on where there is no cover crop.  While the cover crops were not tall I have annual ryegrass roots at least 10″ deep.  Earlier in the fall I found radish roots 9″ deep before the early December snows came.  I found nodules from the crimson clover at 4″ deep (and living crimson clover plants).

I’m not sure why (but I have an idea)…but where I have cover crops I could get the spade in the ground.  Where I had no cover crop the ground was too hard to get the spade in!  Tell me what you think about that!

The first sign of life and death under the snow! The oats were dead, but the cereal rye was green.
The Annual Ryegrass and Crimson Clover were looking quite healthy under the snow.
Annual Ryegrass roots, Crimson Clover Roots, Mycorrizial activity...all working in Feb 2011 in northern Indiana to build my soil!
The Oats were dead but the Radish still had signs of life. That was quite a surprise!
Several Austrian Winter Peas survived under the snow as well. I believe this is because they were so small entering the winter.
Look at the roots! These made my Valentines Day all the more special! I'm not so sure that Mrs. Robison was having the same thoughts...

I’ve attached several photos with descriptions for your enjoyment!

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!