Plant Cover Crops

Learning about the benefits of planting cover crops.

Breaking Up Compaction

Fall Cover Crop Management

While in southern Minnesota in early September 2013 I was asked when a farmer should plow his cover crop field this fall because he needs the fields to be “black” this winter in preparation for next spring.  I shuddered.  There I was in a beautiful field of cover crops that are jump-starting some biology on a “biologically dead” field and the farmer wants to kill his biology driving mechanism.  UG!  The main reason he wanted to till the field was to have warmer soils in the spring where he had black soil.  I shared that our research sowed much different results.  His thought process sound right but has proven to be a myth, not a fact.

A beautiful stand of Oats, Berseem Clover, and Pasja Hybrid Brassica on prevent plant acres in SO. MN
A beautiful stand of Oats, Berseem Clover, and Pasja Hybrid Brassica on prevent plant acres in SO. MN

I told the farmer to leave the cover crops in all winter and use conservation tillage next spring.  (He’s not a no-tiller.)  We dug some shallow root pits for a field day and we found many problems that I believe can be somewhat rectified if the cover crops are left in all winter.

We found many soil health problems in this prevent plant field

  • Severe compaction– many areas had compaction starting at 2-3″ deep.  Part of that was from spring tillage of wet soils…but the compaction was about 8″ thick as the soil was coming up in blocks the size of cinder blocks!
  • Lack of soil biology – I know this because we found a significant amount of corn fodder 2 foot deep that was not even breaking down.  It would have been buried with the deep ripper 18 months ago.  I could not believe my eyes!
  • Lack of aeration in the soil – the soil was literally rock hard.  We did find a few earthworm channels but it was so dry that worms were small and deep.
  • Low organic matter – I’m not sure how low it was but there was very little soil structure.  I talked with a regional NRCS employee and the local SWCD specialist and both men lamented that many of the soils in that region were “about as bad as this one”.
We found corn fodder two feet deep that had not yet decompose after over 18 months.
We found corn fodder two feet deep that had not yet decompose after over 18 months.

I need to be fair.  The farmer currently renting this field has only farmed it a few years and he is making major strides to improve this farm.  But he has lots to accomplish before he has a healthy field.  Having cover crops are a great first step and he knows it.

Other solutions (instead of cover crops) being proposed to fix the “tight” soils (“unhealthy” soils) in the region

  • Tile – LOTS and LOTS of tile has been installed in prevent plant acres this year.  Farmers know they need aeration and percolation in their “tight” soils.  The regional specialist from NRCS lamented that many farmers don’t believe that cover crops are a solution to make their soils better long term.  Tile is not bad; but tile and cover crops are a much better solution.
  • Deep ripping – this will get air into the soil and break up compaction, but will it build soil health?  No, it will not  (note the corn fodder found 2 foot deep in a root pit).  Let cover crops naturally deep rip the soil.
  • Tillage- and lots of it – many fields in the area had been tilled (disked, field cultivated, etc…) four times already to control weeds…Unfortunately it also reduces organic matter and soil structure and soil health.

So what should happen with the cover crops heading into winter?

  • Leave the cover crop growing into the winter – This will give the best opportunity to help with aeration and percolation.  This also helps build soil structure and reduce compaction.  (See deep ripping, and tiling above…just let the cover crops do this naturally!)
  • Sarah Carlson from Practical Farmers of Iowa recently wrote an article about this topic and you can find it here Prevent Plant, Cover Crops, Now What 2013.
  • Let the cover crops keep putting down deep roots – we found roots of crimson clover, radishes, cereal rye, annual ryegrass, oats, and Pasja all around 24″ deep.  Let them keep growing deeper to open up the soil to get air and moisture deeply into the soil profile.
This 5 week old PileDriver Radish shows the compaction zone starts at around 2-3" seep. Roots on this radish went over 24" deep despite very dry conditions.
This 5 week old PileDriver Radish shows the compaction zone starts at around 2-3″ seep. Roots on this radish went over 24″ deep despite very dry conditions.
This field had very poor soil structure. The regional NRCS specialist told me that many fields in the area had similar issues
This field had very poor soil structure. The regional NRCS specialist told me that many fields in the area had similar issues

Root Pit Reveals 40″ Cereal Rye Roots

Rye Pit

I am blessed to hear from farmers around the world about their cover cropping adventures.  One young man, Brian Scott, from Carroll County, Indiana has generously shared his information with me again this spring.  This post is Brian’s report from early May, 2013.  To see Brian’s photographs, click here.

We dug a few pits in our field today that has about 40 acres of cereal rye and another 40 of annual ryegrass. The cereal rye had a pretty good stand, but the ryegrass didn’t do so well over the winter.  Looks like we may not be the only farm with that problem this year?

Anyway I was pretty excited for our first year cover cropping that we found cereal rye roots down to 40″ today!  And we hit the water table below that since everything is still relatively wet from all the rain.  I wouldn’t be surprised to see more roots if we could have dug down deeper.  That was on pretty good soil that used to have manure applied every year until about 7 years ago when we got out of the hog business.

The ryegrass was on ground with much more clay near the surface, but I was glad to see we had roots down 2 feet where we did get a decent stand.

Both covers were sprayed today.  I think I would have liked to keep the cereal rye a bit longer, but with rain in the forecast we didn’t want it getting out of control if we got soaked again and couldn’t spray.  These were all seeded into standing corn on 9/19/2012.  In all we had about 200 acres of cover this year and have plans to seed at least 400 in the fall!

Thanks Brian!  And to everyone who have been sending info…watch for it to be on the blog soon.  Thanks to all who are sharing their stories.

Followup in On-Farm Cover Crop Trial

The corn is now harvested at Robison Farms in rural Greenwood, IN and we are pleasantly surprised.

Accurate Yield Estimates

We actually achieved a somewhat higher yield than the hand check “guesstimate” that my brother Don and I made back in August.  We reported this yield in the blog post Cover Crops Provide Improved Corn Yields in On-Farm Trial .  The actual yield was 107 bushels per acre across the whole field and our estimate was in the  105+ bushels range.

This gives me confidence that the differentiation we showed in the yield in the different cover crops and cover crop mixes was pretty accurate.  As you will see on the blog post there were some mixes that yielded more than 50 bushels per acre better than the no-cover crop check.

Impressive Root Structure and Soil Moisture

Would the whole field have averaged 50 bushels per acre better if it had all been in cover crops in 2012? I doubt it.

But I think it would probably have been quite a bit better than what the field averaged without cover crops. Here’s why:

  • Better Root Growth
  • Greater Amount of Soil Moisture

One reason that I think there would have been a significant yield increase over the whole field is because of what Don and I found when we dug up some plants. We found more moisture and more roots where we had cover crops versus where we had no cover crops.

In the non-cover crop area:

  • We had to use a shovel and a pick-ax to dig.
  • The ground was exceptionally compacted, hard, and dry.

In the cover crop area:

  • We used just a shovel to dig.
  • We had much less compaction (in most areas).
  • It was distinctly more moist (like comparing a fairly dry sponge versus a sponge that had not been submerged in water for 2 months).
This corn plant was dug up in the area where we had a cover crop mix in mid-August 2012 under severe drought conditions.  Note the additional root and the moistness of the soil compared to the photo to the right.

 

This corn plant was dug from the non-cover crop check area with a pick-ax and shovel. The ground was compacted, hard, and very dry. It is amazing that the corn looked as good as it did!

 

 

 

 

 

 

 

 

 

 

Don Robison holding up a corn plant from the cover crop plot area that had Austrian Winter Peas and Radishes.  Look at the root-ball and moisture compared to the next photo.

Don is not working near as hard to hold this corn plant from the non-cover crop check area. The root ball was smaller and the soil was much drier. I’m not sure why Don was smiling. Most of the 50 acre field did not have cover crops! Like Dad would sometimes say, “get that smile off your face!”

Earthworms

As Don and I were digging in the areas where we had cover crops we were pleased to find earthworms. There were no earthworms to be found in the non-cover crop check area.

This field has been no-tilled for most of the last 20 years and we usually find earthworms, but it was so hot and dry that I assume the worms either died (fried) or went deep into cooler, more moist soil (this year that may have been 5-6 feet deep).  But again, we found some earthworms in the cover crop plot area.

In retrospect, we should have compared soil temperatures on the day we dug roots and took yield estimates.

An earthworm in the cover crop plot area. Though we did not see many in the plot area we saw none in the non-cover crop check area.

 

As dry as the summer of 2012 was, it was interesting to find earthworm activity in the area where we had the cover crop plots. There was no such activity evident in the non-cover crop check area.

 

 

 

 

 

 

 

 

 

 

 

The Takeaway Message from Robison Farms in 2012

  • Cover crops can increase corn yield even in very dry years.
  • Corn following cover crops consistently out yielded corn that was not following a cover crop in hand check yield estimates.
  • Hand check yield estimates were consistent to actual yield on the non-cover crop check.
  • Cover crops can help preserve soil moisture even in a severe drought.
  • Corn roots following cover crops appeared to be consistently larger and deeper than where there had not been a cover crop.
  • There was more earthworm activity in the cover crop areas.
  • There was less compaction in most cover crop plots compared to the non-cover crop check.

In a future post we will look at “Crop Health Imaging” maps that Beck’s Hybrids did for our farm.  These were taken a bit late in the season but they were still very interesting…and telling!

 

 

 

 

 

Cover Crops Planted After Wheat in a Dry Year

Can you still gain value in a cover crop when it is planted after wheat in a dry year?

During the week of October 15, 2012 I traveled a wide swath of Wisconsin looking at cover crops.  In the eastern half of the state the cover crops looked very good.  In the western half the cover crops looked desperately poor.   The difference?  Moisture.

Northwestern Wisconsin – Terribly Dry

While on farms near Osceola, WI (right along the St. Croix River – the river that forms the border between Wisconsin and Minnesota in that part of the state), I observed a sad sight.  Cover crops that had been in the ground for 6 weeks were either not germinated  or had little growth.  While the early part of the growing season had more than adequate rainfall and corn yields were near 200 bu/acre, the last 7-8 weeks has seen less than 1/2″ and the cover crops look…well, they look horrible.

Central Sands Region – Dry But with Some Promise

Near Hancock, in the Central Sands Region of Wisconsin, there is a mixed bag of results.

Where farmers used irrigation to “water -up” the cover crops, there are nice stands with adequate growth to have a “successful” cover crop to achieve many benefits.  Unfortunately, where there was no irrigation used there was much less “success.”

Again, it was dry for several weeks before and after the cover crops were planted after the wheat crop had been harvested.  A few days before my cover crop field day there was a 4 inch rain.  The farmer and dealer present said that the plot “changed overnight” as it had grown so much since there was some moisture.

The beautiful thing about the cover crops in the central sands is that they established and actually looked amazingly good compared to what I envisioned they would. The winter cereal rye was tillered nicely and the oats were 5-6 inches tall.  The radishes, oats,and rye all drilled through the compaction zone that we found at 3-4 inches deep.

What was not apparently impressive was the crimson clover or Austrian winter peas – at least not for coverage or height. The crimson clover was only about 1 inch tall and the peas were 3-4 inches tall.  However, what was surprising was how many nodules were on the clover and peas and that the roots were 4-5″ deep and through the compaction zone as well!

Northeastern Wisconsin – What a Difference Moisture Makes

The crimson clover was not at all impressive even though the seed was planted 7 weeks previous to this photo being taken. However, with virtually no rainfall it is amazing there was any clover established at all in the Central Sands Region of WI.
Seven or eight weeks of dry weather did not help cover crops in this field near Osceola, WI emerge very quickly in 2012. Will there be any value to this cover crop? Sadly, no.  Note how small the radishes and turnips are.  These cannot be declared valuable to this farmer.  Thankfully the winter Rye should survive the winter.

 

 

 

With less than 1/2″ of rain since planting into dry soil, this cover crop field in western Wisconsin near Osceola never had a chance to achieve the goals the farmer had for it improving the soil.

 

 

 

 

 

 

 

 

 

This is the test plot in the Central Sands Region.  From Right to left; Radishes, Oats, Winter Rye, and various mixes. Are these cover crops valuable? I believe so because they are through the compaction zone and the rye and many of the mixes will have components that survive the winter.

 

 

If you enlarge this photo you will be amazed how many nodules are on this tiny crimson clover plant. The roots were over 5″ deep which was through the compaction zone at the Hancock, WI plot.

 

 

 

 

 

 

 

 

 

Cover Crops and Bears?

Radishes, Crimson Clover, and Bears

Walking in cover crop fields in northern Indiana is easy compared to doing it northern Wisconsin.

In northern Indiana my main issue is tripping over large radish tubers sticking out of the ground.

In northern Wisconsin my main issue was that plus watching out for bears. I’m not talking about the Chicago Bears…but real live black bears!  Although I did not see any while conducting cover crop field days near Coleman, WI on October 18, 2012, hearing the stories about the bears raising havoc while AgVentures Co-op employees were harvesting corn plots made me quite nervous.

The cover crop plot was fabulous. There were 5 different mixes to observe plus straight radishes planted at 8#/acre.  The cooperator plans on taking yield tests over each different cover crop mix in his 2013 corn crop.  If he is able to do that I’ll keep you informed of the results.

This cover crop plot near Coleman, WI had beautiful radishes with large tubers – and thankfully NO bears!

 

 

 

 

 

 

 

 

 

 

 

 

The radishes were from 1″ to 3″ in diameter and quite deeply rooted. There was manure applied after wheat harvest so the radishes were “well fed”.

 

 

 

Cover Crops Provide Improved Corn Yields in On-Farm Trial

All of what is reported below was accomplished after only one year of cover crops.  This work was inspired by a conversation Don and I had last winter with Dr. Eileen Kladivko from Purdue University.  As I say in cover crop meetings,

Don’t expect a miracle the first year – but look for one.

Over the exceptionally dry and super hot late-spring/summer months of 2012 my brother Don Robison collected “plant-health” related data on our corn field at Robison Farms near Greenwood, IN.  Don took data on the corn  from each area of the cover crop plot we planted last fall over the top of a soybean field as well in the “check area” (no cover crop area).

The data he took throughout the summer included plant chlorophyll readings, plant height, and compaction readings.  I presented some of the chlorophyll data on the CropLife Webinar and at several cover crop meetings this summer (and more is posted below).

On August 15th Don and I took hand harvested yield checks from each area and from the check area.   The data on the corn yield was almost identical to what we found with the chlorophyll data and compaction data. Where we had the healthier plants all season long (more “green-ness” and deeper roots) we had higher yields.

To figure yield we utilized this formula we found at a Purdue University agronomy website.

Each cover crop treatment out yielded the “no cover crop check”. The top three yielding plots also had the least compaction and highest chlorophyll readings through out the drought stricken summer.  The check plot yield was 105.24 bushels per acre.  The top yield estimate was 164.82 bushels per acre.

 

The area where the plot was had a 24″ water line was installed by the county in 2009; so it was intended to be a “rescue disturbed soil trial”.  The corn was not harvested directly over the water line but it was where the soil from the water line was mixed in with the top soil.  In 2011 the field was in Soybeans and yielded 48 bushels/acre.  In 2010 the field was corn and yielded 198 bushels/acre.  The whole field has been no-tilled for most of the past 20 years (there were some years with conventional tillage done – mainly in the early 90’s).  175 Units of N were applied (100 units (28%) with the chemical burn down application early season and 75 units side dressed (28%) in early May).

Rainfall from May 1 to July 31 was 2.24″ (with only 0.75 from May 1 to July 19).  There were 42 days over 90 degrees and 8 days over 100 degrees during that time.  All time record dry and heat was recorded in July, 2012 in the area.

Don took chlorophyll readings weekly (one week missed in July due to a family vacation).  He took 30 chlorophyll readings per plot per sampling date.  He also took multiple plant height readings each time as well.  He followed the manufacturers instructions on the chlorophyll readings and penetrometer tests.  Don spent a lot of time in this field so we could all have this data!  Thanks to The CISCO Companies for providing the seed, equipment, and Don’s labor to collect this data.

 

This chart shows the percentage above the no cover crop area (the “check”) compared to the different cover crop mixes. The two comparisons on the far right are from a soybean study we ran where we had cover crops two consecutive years compared to one year (more data and a post coming soon on this study).

Observations:

  • The plot areas that rated healthier (more green-ness and taller) yielded the best.
  • The plots areas where there was less compaction yielded the best
  • The plots with annual ryegrass did not fare as well as some others in this drought year – yet was still considerably above the check.
  • Not all plots with radish were “top” yielding – however two of the top three yielding plots had legumes plus radish.
  • Plots with legumes were generally healthier all season long and their yield reflected that.
  • I doubt that the whole field will average over 100 bushels/acre.  As with all hand yield tests they are estimates but I believe that the comparison is very accurate.
  • The Austrian Winter Peas, Crimson Clover, and Appin Turnips overwintered “beautifully” and were growing aggressively when sprayed at burndown.
  • There was a considerable amount of earthworm activity in the cover crop area but only a few earthworms were found in the “check” area. That is unfortunate because 2 acres were covered and 48 acres were not!
  • There were more corn roots in the plot areas we dug vs. the check area (watch for a new post coming on this soon).
  • There was more moisture in the soil where the cover crop plots were compared to the check area.
  • The soil structure was considerably better in each cover crop plot vs. the check area.
Don recorded over 180 chlorophyll readings in each cover crop plot and check plot over the summer.

 

The check plot had 175 units of nitrogen plus the whole field had been soybeans the previous year. While the annual ryegrass blend plot was above the check all season long it was not up to the desired level until after the July 19 rain event.

 

The plot with the Oats and Rye and Appin Turnips was impressive most of the spring and summer. It was at or above the desired rating until August. It was very impressive right after the July rain event and that is possibly why it had the second highest estimated yield. By the way, the turnips did live through the winter.
All season long I was convinced that the plot where the Austrian Winter Peas and Radish were was going to have the highest yield based on the data shown above (and plant height readings). It beat the second place entry by less than 1/2 bushel in the yield estimate.

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 Enhance Water Infiltration/Percolation

In late September of 2011 I was walking in our family corn field in central Indiana–in the pouring rain. Following the wettest spring in the eastern corn belt in 100 years we had a summertime drought that saw less than 2 inches in July and August combined. In that same time period we had 32 days above 90 degrees.

We just had 3 inches of rain yet my soil was dry at 1/2 inch in this area that had been tilled wet in the spring.

On this September day we were having rain…3 inches worth of glorious rain! I threw on my rain coat and Tingley boots, grabbed my shovel and went into the corn field where our cover crop plots had been planted in the fall of 2010 and killed in May 2011. As I walked through the field I noticed that where the soil had been tilled (see previous blog post) I was seeing dry soil underneath my boot track! Now catch the scene here…no rain for much of 60+ straight days…now a 3″ rain and virtually none of the moisture getting into the soil! Literally I had less than 1/2″ of the soil depth that was moist! Dry footprints followed me all the way to the end of the field. I was not happy.

When I reached the area where the cover crop test plot was (that area was not tilled this spring) I dug into the check area that was no-tilled yet did not have a cover crop. In that area I dug into the soil and I found moisture 2 1/2-3 inches deep. This area was now no-tilled for 23 straight years. That made me feel better.

Water was standing (or running off) of the soil that was tilled wet in the spring of 2011. There was very little infiltration from a 3 inch rain

 

In this photo we see infiltration at 2 1/2 - 3 inches deep. This soil has been no-tilled for 23 straight years.

 

Then I dug in the area that had been no-tilled for 23 straight years and had a cover crop the previous winter. I was very pleased when I dug in the areas where we previously had annual ryegrass and cereal rye and found moisture had filtered (penetrated) in 7 (seven) inches deep!

Water infiltrated 7 inches deep where we had corn no-tilled into cover crop rye.

 

 

 

This section of the field had a cereal rye cover crop in 2010-11 and was no-tilled. Note the lack of water standing on top of the soil! Where did the water go? Into the soil!

 

Watch these videos on what I found when digging for earthworms in this sections with cover crops and no-till and where there was tillage without a cover crop. I believe we have an additional answer to why I had so much better infiltration where I had the cover crops..earthworms and roots!

This "rogue" radish provided information that we had a compaction zone at about 3 inches deep in our no-till field; thus reducing water infiltration where we had no cover crop.

Yet, I wondered, why did the moisture stop at 2 1/2-3″ in the no-till plots? I found the answer from a rogue radish. We had a few radishes that came up in the field that had been planted in the fall of 2010 (the fall of 2010 was so dry that many of the radishes did not come up until very late…or not until spring, or in a few cases until mid-summer).  As I previously wrote, Radish does have some hard seed.  I dug around one of the radishes and found a constriction in the radish at 2 1/2-3″ deep! Even after 23 years of no-till I still had a compaction problem! I believe that is one reason why cover crops help producers to transition from conventional tillage to no-till…cover crops penetrate through compaction layers.

Short Cover Crops Put Down Deep Roots

Many cover crops were planted in September and even into early October in much of the Midwest in 2011.  Some of those cover crops are not very advanced in their growth by mid-November. Does this mean that they are useless or worthless?  As I often say in meetings or at field days…”always take a shovel with you.”  You will likely be surprised!

I have been in several root pits this fall and also have dug up dozens of cover crop plants.  One of my goals in the field is to measure roots on species like annual ryegrass, cover crop radishes, oats, cereal rye, Austrian winter peas, rape, kale, cowpwea, Hairy Vetch, Phacelia, turnips, and crimson clover.  Some of the cover crops were in fields that were long term no-till and some were conventionally tilled.

So what have I found so far?

  • Four inch tall Annual Ryegrass with 21″ deep roots

    Very little top growth does not mean very little root growth. This radish had well over 12" of root depth.
  • 15″ deep radish roots that had 2″ tall tops and a “pencil” sized tuber
  • 12″ deep crimson clover roots under a 2″ tall top (with many nodules)
  • 35″ deep roots on oats that had 20-25″ tall top growth (prevented planting situation planted in early September)
  • 30″ deep roots on radishes that had 20-25″ tall top growth and 2-3″ diameter tubers (prevented planting situation planted in early September)
  • 12″ deep roots under 18″ tall Austrian Winter Peas (planted in late August after wheat)
  • 20″ deep cereal rye roots with 6″ tall top growth (planted in late August after wheat)

While it would be nice to have more top growth, what’s below the soil surface is impressive.  As I learned from Dr. Eileen Kladivko from Purdue University nearly 8 years ago…it’s what is below the surface that really counts for most farmers.

Earthworms were abundant in the cover crop soils, but not so much in the non-cover cropped fields.  Another factor that was impressive was the amount of roots…or the density of the root mass in the soil, even on the short cover crops.

So why does this matter?  If we are to have better soil structure we need living roots.  If we are to have better erosion control we need living roots.  If we are to scavenge nutrients, we need scavenging roots.  In fact, the roots are what gives us the vast majority of the positive benefits most producers find with their cover crops.  Cover crops farmers can’t be “windshield” farmers…they need to have their shovel with them…and when they see the roots, that’s when cover crops get the most exciting to them…and me.

 

It's hard to believe it but this short crimson clover had roots over 12" deep. The roots had many nodules on them as well.

 

These cover crops were flown into a seed corn field in NW Indiana in early September. Both the radish and annual ryegrass had roots over 20" deep.

 

There were many earthworms in most of the cover crop fields and in cover crop plots, especially when compared to areas without cover crops.

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!