Plant Cover Crops

Learning about the benefits of planting cover crops.

Higher Yields

Benefits of a Pure Stand of Cover Crop Red Clover

December 28, 2020

by Dustin Johnson

I recently plowed under a successful stand of red clover in an organic wheat field on my farm near Kokomo, Indiana. I have grown alfalfa and mixed stands of hay as a cash crop for my entire career. Five years ago we began experimenting with organic grain production to try something new and take advantage of the synergies between organic grain farming and our existing hay business.

This was my first experience growing a pure stand of red clover. The main goal for the stand was nitrogen fixation for next year’s organic corn crop.

Along the way, I also gained a forage harvest, weed suppression, and soil health benefits. Please read further for a more in-depth discussion of my experience and the benefits that this time-proven practice can bring to your farm.

FROST SEEDING

On February 21st, I broadcasted 15 lbs/acre of red clover seed into my dormant wheat field. Frost seeding should take place near the end of winter when a period of nightly freezing and thawing is anticipated. The ground was frozen enough to hold up the tractor and the field contained a light dusting of snow. This helped me see the spread pattern of the clover seed.

Red clover is my personal first-choice when frost seeding: The seed is relatively inexpensive, clover can thrive underneath a crop canopy, it can be harvested for dry hay, and it works! Red clover seeds are heavy and round with a high level of seedling vigor. They naturally sort through material on top of the soil and fall into the “honeycomb” of soil cracks created by frost. This is the same process by which red clover stands naturally persist on road sides and barn lots.

If grazing is your primary goal, plant an improved species such as Bearcat or Gallant. White and berseem clover can also be successfully frost seeded for forage use. If you plan to exclusively grow it as a cover crop, sweetclover and mammoth red clover are also good choices.

Around the time my wheat broke dormancy, the red clover seedlings emerged. The frost seeded clover scavenged sunlight that filtered through the rows of wheat, but grew more slowly than the wheat and stayed beneath the wheat canopy. The presence of red clover in the wheat field did not interfere with the wheat’s ability to grow or be harvested. From the road, the wheat looked like a normal wheat field. Only after harvest was a carpet of green growing clover revealed.

FORAGE HARVEST

Once the wheat was harvested and the canopy opened to the red clover, it grew very quickly. I mowed the red clover for hay about a month after wheat harvest on August 19th. The clover was nearing full-bloom and the weather was right. The hay was mostly red clover, but also contained a few weeds and about 4” of wheat stubble. This medium-quality hay was the most fragrant, sweet-smelling hay that I have ever baled! Yield was also impressive: 2.3 dry tons/acre in a single harvest. Even priced modestly, this hay harvest was a significant boost to the profitability of my wheat crop.

COVER CROP VALUE

After taking a cutting of hay in August, I let the summer regrowth accumulate for a green manure to plow down. The regrowth was vigorous and thick. Weeds that had been present in the growing wheat were mowed before going to seed by the wheat and hay harvests. Newly germinated weeds could not compete with the established red clover. This certified organic field was nearly weed-free in late summer.

The clover bloomed again in September and was a haven for wildlife and pollinators.

In early December, I moldboard plowed this land and the red clover again showed its value. The clover was still actively growing and removing water from the soil. Areas of the field that did not have a good stand of clover were noticeably wetter. The clover taproots penetrated the plowing depth and prevented the wetter clay soils from “slabbing.” The pictures below show the loose friable soil created by the clover roots compared to an area of shallow-rooted grass sod plowed at the field edge.

Note the difference in the above plowed soil (with clover) vs. the soil below (no clover).

Those same roots will provide a soil health benefit below the plow layer as well. The clover taproots penetrated the soil much deeper than the plowing depth. The roots will help prevent a plow pan from holding water when they decompose this winter and drainage occurs in the old root channels.

The red clover has now begun to decompose within the soil profile and will be releasing nitrogen for my organic corn crop next spring. University sources estimate that a successful stand of red clover that is terminated after blooming can release 70 to 120 lbs of N per acre.

Now is the time to make preparations for frost seeding clover on your farm. Whether your goal is nitrogen fixation, improved pasture quality, or soil health, frost seeding clover this winter is an easy and cost-effective way to achieve big results.

Results of Farmer Cover Crop Survey Conducted by SARE and CTIC

Folks,
If you want to see how cover crops provide a very good ROI across a wide geographic region then this report is for you!  Thanks to Rob Meyers from SARE and the folks at CTIC for conducting and publishing this survey.  It helps me to see that the results on our home farm (and many of your farms too) were duplicated over a broad area.

Cover crops REALLY help with yield :)
Cover crops REALLY help with increasing yield 🙂            (BTW, we are NOT really standing up.)

Here is Rob’s e-mail.  Check out the link to see the whole report.
We are releasing today the results of a farmer survey on cover crops that was conducted by SARE and the Conservation Technology Information Center (CTIC) this past winter.  A majority of the surveys were completed by farmers attending Midwest conferences this past winter but we also had some respondents to the online version of the survey from across the U.S.  The survey analysis and report development was completed by CTIC under a contract from North Central Region SARE.  Questions on the survey were developed with the input of MCCC steering committee members.  The report is available online at:  http://www.northcentralsare.org/CoverCropsSurvey
Key findings included the following:
  • During the fall of 2012, corn planted after cover crops had a 9.6% increase in yield compared to side-by-side fields with no cover crops.  Likewise, soybean yields were improved 11.6% following cover crops.
  • In the hardest hit drought areas of the Corn Belt, yield differences were even larger, with an 11.0% yield increase for corn and a 14.3% increase for soybeans.
  • Surveyed farmers are rapidly increasing acreage of cover crops used, with an average of 303 acres of cover crops per farm planted in 2012 and farmers intending to plant an average of 421 acres of cover crops in 2013.  Total acreage of cover crops among farmers surveyed increased 350% from 2008 to 2012.
  • Farmers identified improved soil health as a key overall benefit from cover crops.  Reduction in soil compaction, improved nutrient management, and reduced soil erosion were other key benefits cited for cover crops.  As one of the surveyed farmers commented, “Cover crops are just part of a systems approach that builds a healthy soil, higher yields, and cleaner water.”
  • Farmers are willing to pay an average (median) amount of $25 per acre for cover crop seed and an additional $15 per acre for establishment costs (either for their own cost of planting or to hire a contractor to do the seeding of the cover crop).
Please help us distribute this information to your colleagues and farmers in your region.
Rob Myers, Ph.D.
Regional Director – Extension Programs
North Central Sustainable Agriculture Research and Education (SARE)
University of Missouri
238 Ag Engineering Bldg.
Columbia, MO 65211-5200
Phone 573-882-1547
Email myersrob@missouri.edu
Web http://www.northcentralsare.org/

Are Cover Crops Profitable to the Farmer?

Establishing the row crop into a cover crop is vital for success. Very rarely do I see this as a problem as farmers do a great job of "precision planting" corn and soybeans.
Establishing the row crop into a cover crop is vital for success. Very rarely do I see this as a problem as farmers do a great job of “precision planting” corn and soybeans.

Cover Crops: Will I Get a Return on Investment

Over the past two months my brother Don Robison and I have had opportunities in Indiana, Iowa, and Wisconsin to share a presentation entitled “Return On Investment from Cover Crops.”  I will do the same in Ontario and Michigan over the next few weeks.

Sarah Carlson from Practical Farmers of Iowa told me that after Joel Gruver and I spoke in Iowa that farmers were leaving the presentation room excited and ready to plant more cover crops in 2013.  That gets me excited!

However, do cover crops always show extra profit for every producer in every field?  The answer is “no.”

Robison Farms Research Plots

In a previous post I shared data, along with the other interesting benefits, that we found in our long-term no-tilled soil – compared to the same soil with cover crop plots.

However, the real reason we did the research was to find out if we could be even more profitable when using cover crops with no-till instead of just long-term no-till.  What we found was a significant increase in profitability in each of our plots in 2012.

The net revenue on each cover crop species or mix was considerable on our farm in 2012.

The net revenue on each cover crop species or mix was considerable on our farm in 2012.  We used $5.75/bushel as the value of our corn.

 

The “worst” profit improvement was $41.78/acre and the “best” was $286.94/acre – impressive figures.

However, we did see additional benefits that may not always add this kind of improved profit:

  • increased earthworm activity
  • improved root mass and root depth
  • improved water infiltration
  • improved plant health

But these may not always add profit.

Other  $uccess Stories

Since the inception of Plant Cover Crops.com, many farmers I’ve gotten to know have had increased yields and profits.  Dave from Central Indiana has had very good success with improved profitability and improved soils.  Dave, from NW Ohio, has seen improved yields and profits following cover crops most years.

Others like Dan DeSutter, Rodney Rulon, Terry Taylor, Cameron Mills, and Larry Bonnell have had great success and continue to use cover crops more and more while refining their systems to fit their needs and management practices.

It is easy to see the area where the soybeans were planted into tilled ground over a new tile compared to the soybeans no-tilled into winter cereal rye.
It is easy to see the area where the soybeans were planted into tilled ground over a new tile compared to the soybeans no-tilled into winter cereal rye.

Cover Crop Disappointments

As I said earlier, not every farmer will have success with cover crops every time.

Bob Ormiston,  from NW Indiana, recently e-mailed me about his 2012 experience.

Last year we had three fields of cereal rye which we sprayed about the time the rye was starting to head.  In two of the fields, we had worked new tile lines to level the ground and wiped out the cereal rye.  There was an enormous difference in the quality of the bean stand, and the no-rye tilled beans were significantly taller than the beans planted into the rye.  I think it is fair to say that in 2 of the 3 fields we took a 5-10 bpa yield hit because of the cereal rye.  The problem was very likely compounded by the crazy dry and hot weather.  The field with the best stand made 58 bpa.  The other two around 49.

Bob later commented,

The beans in the worked areas of the cereal rye had a much better stand and throughout most of the growing season they were taller.  They were all drilled with a JD no-till drill.  The rye was around 20 inches tall and starting to head.  The beans were planted about 1.25 inches deep.  Weed control was excellent and both glyphosate and Extreme were utilized.  To reiterate, I felt the perceived yield loss in 2 of our 3 bean fields was a direct result of the drought and high temps.  The 78 acre field that yielded 58 bpa received substantially more rain and generally had a much better stand than the other 2 fields.

Tom Burlingham from Wisconsin notes,

›Neighbors plot had 10 bu less corn per acre where there was radish cover after 2011 wheat. 75 vs 65. Three strip trial with UW Ext. (Under exceptionally dry conditions.)

Multi-Year Research from Iowa

A three year study done by Practical Farmers of Iowa has shown both improved yields AND also yield loss when following winter cereal rye with corn and soybeans. It is important to note that when yield was lost it was sometimes a failure to control the cover crop adequately.  However, that was not always the case – their 2010 corn yield following winter cereal rye was negatively impacted in each of their locations.

Conclusions

While cover crops have been the “hot topic” over the past 3-4 years we still have a lot to learn.

Some experienced cover croppers may scoff at losing yield and claim it is because only one species was used as a cover crop – that we all need to use “cocktail mixes.”

Others may say that using one species is all they are comfortable with managing.

Both groups might be correct in their thinking.  But each individual farmer must make his own choice of what he can deal with (or wants to deal with).  Bob Ormiston is investigating using Hairy Vetch and Crimson Clover with a grass mixture in 2013 before his 2014 corn crop.  My brother, Dad, and I are looking to do straight winter cereal rye before all of our soybeans in 2014.

Whatever choice a producer makes should always have a goal of improving the soil health.  If the soil is healthier, then usually a better, more profitable crop will follow.  But it does not always happen that way.  Like many things in life, patience and best management practices usually pay off – and most likely will always pay off in the long run.

I’m interested to hear about your experiences using cover crops. Have you seen a benefit? Have you struggled? You can share your thoughts below in the comment section or send me an email.

 

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 Increase Iowa Corn Yields

Cover crops are helping to increase yields in Iowa corn fields.  My friend Sarah Carlson from Practical Farmers of Iowa sent me the following testimonial from Eric Franzenburg from east central Iowa (about 1.5 hours east of Ames).

Eric Franzenburg has seen increased corn yields of 20-40 bushels per acre the past 3-4 years after using cover crops!

Thanks to Sarah and Eric for making this testimonial public.  I know that there are many other farmers that have seen similar results.  If you have and would like to share with the readers of plantcovercrops.com I’d greatly appreciate it!

Eric’s testimony:

I believe that the researcher from the article is on to something in regard to relieving drought stress (research I proposed on this blog).

I went out to do some yield checks on our conventional corn fields about a week ago to get an idea where we were.  One of the fields was seeded with fall rye earlier in the fall (September 1, 2011), followed by 3,000 gallons/A of hog manure (later in the fall). This spring we killed the rye with Roundup when the rye was over knee high, waited over 2 weeks to plant, tilled one pass with tandem disk-harrow, and planted later in May. It was the last field I planted.

I followed with a sidedress of 70 lbs at V6. This field will out-yield all other fields by 40 bpa.  The plant health is excellent, and I was telling Sarah that if you start poking around looking for rye residue it is virtually gone (not sure if this is good or bad).

We have been doing this same program for 4 years now and I am no longer worried about planting corn the third week of May under these conditions, especially after this year; this has been a very telling growing season. We are coming up with the same results 3 of the 4 years (yields 20-40 bu. higher).

I have been wondering what the mechanisms in the soil are that have given us these results.  While the scenario that the researcher has proposed sounds good, it does not sound like much work has been done to prove this out.

Cover Crops in Wisconsin – Full Speed Ahead!

This cover crop field was ready for harvest in late September 2012.

I took a new management position in May of 2012 with Wisconsin based Legacy Seeds, Inc.

While my main responsibility lies in working with alfalfa and forages I also was pleased to find out that there were several folks in Wisconsin that were using cover crops!  Well, you would figure that I’d get involved more with cover crops in the Badger state, and I have.

Wisconsin Cover Crop Meetings

In February 2012 I conducted two cover crops meetings in the Fox Lake, WI area with over 75 producers present. The purpose of these meetings were to teach farmers about how cover crops can work in their farming operations.  I was very pleased with the outcome of those meetings as over 10,000 acres were planted on farms that were represented at those meetings.

In July I held three more cover crop meetings in Eau Claire, Waupaca, and Brillion, WI. All combined, there were over 150 farmers present and I’m confident that there were at least 30,000 acres of cover crops planted by those farmers.

While I don’t have figures of how many cover crops were planted in Wisconsin, I think there were as many as 250,000. Many of those acres were after wheat was harvested and a surprising number after corn and soybeans.

Cover Crops for Forage & Manure Management

Feed was one reason so many acres were planted. The severe drought has created a forage shortage.

But many farmers planted their cover crops because they want healthier soils and better production.  Still others planted because they want to hold onto the nutrients from their manure.  Whatever the reason, cover cropping is alive and well in Wisconsin – and growing.

You can click on the pictures below to see a larger image of each.

The Oats, Appin Turnip and Cowpea combination should make excellent haylage for the Wisconsin dairy market.

The nodules on the Austrian Winter Peas were multiple and large. This field will be planted to corn next year and it sure appears that a good amount of nitrogen will be in the soil and available for that corn crop.

This field of Austrian Winter Peas and Radish east of Green Bay, WI was planted after wheat in severe drought conditions. Thankfully some later rains came to get the mixture up and going.

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.

Inoculating Cover Crop Legumes Pays Off

Several farmers have asked me why they need to spend an “extra” 4-6 cents per pound to inoculate the legume seed they are planting for producing nitrogen with their cover crops.  I get asked this especially about Austrian Winter Peas and Cowpea.

However, if you are planting Crimson Clover, Berseem Clover, Kura Clover, Alsike, Hairy Vetch, Sunn Hemp, or Medium Red Clover it’s just as important inoculate!  Why?  I’ll list a few reasons below:Inoculated peas are significantly better at producing nitrogen

  • Legumes are planted as cover crops most specifically to produce nitrogen.
  • Legume seed is relatively expensive; if it does NOT produce nitrogen, then it is exceptionally expensive.
  • The inoculant is a species specific bacteria that allows that plant to fix nitrogen.  If there are not enough bacteria there is limited nitrogen production from the legume plants.
  • A healthy legume cover crop can produce nearly 200 units of nitrogen
  • Even if you have produced a similar crop in your field within a two year time period, it still pays to inoculate each year since many of the bacteria prove to be “weak” and unable to perform like a healthy and vigorous bacteria.
  • If inoculating Peas or Cowpea you will need to do a “seedbox” treatment.  There are not yet inoculants that can be pre-applied that will allow you to have healthy bacteria. Therefore, most inoculant companies suggest putting the inoculant on within hours of putting the seed in the ground.

Be sure to get very good coverage on all of the seeds.

Do not hurry. Each seed needs coverage to actually be inoculated. I know that sounds silly, but I have seen many fields and plots where only some of the pea or vetch  plants were performing well.  The ones that looked poor had no nodules.

Many companies sell pre-inoculated clover seed.  If yours does not, then either find another supplier or purchase the correct inoculant from your current seed supplier.  Do not waste a great opportunity to produce as much nitrogen as possible. It is  less expensive to produce nitrogen than it is to purchase it.

A well inoculate Austrian Winter Pea nodule will be pink inside like the one above.

This photo shows a mixture of well inoculated and poorly inoculated Austrian Winter Pea plants. It is important to inoculate each seed with the nitrogen fixing bacteria.

 

 

Cover Crops in the Great Plains – a view from a long time cover crop user- Part 2

In this cover crop post I again quote Paul Conway from Kansas, who is giving his input on cover crops in the Great Plains. In this article, Paul shares his experience with Austrian winter peas, field peas, chickling vetch, and hairy vetch.

Dave,

Austrian Winter Peas: I have limited and disappointing experience with Austrian Winter Peas.  They always winter kill and they must be planted at an inconvenient time.  It seems that the areas where they do well do not follow a simple geographical line.  Austrian Winter Peas do very well about 60 miles south of me in central and southern Kansas.  Ironically, they seem to do fine in the Nebraska panhandle, which is much colder than we are. I think consistent snow cover makes the difference.

Field Peas: also know as Canadian field peas or forage peas. I’ve grown these in early fall with oats and forage radish. I don’t know how much nitrogen they fix but they do winterkill by early winter –  mine haven’t died yet – probably consistent lows in the middle teens will do it.

I also plant them in early spring the same time as oats, killing them for June planted cash crops.  Mowing after flowering will effectively kill peas.  Where peas shine is in mixes and in cool climates.

The pea/oat or pea/triticale is excellent for haylage or silage. These mixes have the same benefits for livestock farmers as the soybean/summer grass mixes.

In much of the Midwest and east, double cropping is possible, oat/peas followed by soybean/milo or sorghum-sudan.  Further north, the oat/pea mixes would mature too late.  In that regard, I think that field peas could be managed as a summer annual (like soybeans) in the Great Lakes states, upstate New York, Pennsylvania, and New England.

Peas can handle routine summer temperatures in the low-mid 80s. Peas can be grazed. Peas aren’t shade tolerant so they don’t do well when sown into row crops.  Frankly outside the mixes I think the clovers may be more versatile.

Chickling Vetch: Also known as “AC Greenfix.” It will fix nitrogen faster both in the fall (it winterkills about the same time as the peas) and in the spring.  AC Greenfix seed is more expensive and harder to plant due to it’s shape.

Hairy Vetch: As you know, hairy vetch is the strongest nitrogen fixer among the annuals.  Hairy vetch easily fits into vegetable rotations. I have seen two foot vine growth and numerous fat nodules on vetch in early-mid April after a mildly wet fall and an early spring.  It will be harder to fit into field crop rotations, especially corn-soybeans.

Here the optimum time to plant hairy vetch is September, but it can be planted as late as mid October.  It needs minimal soil contact which isn’t a problem in a normal fall. A dry September/October, like I had this year, is a problem.

I know that you have some experience with flying in hairy vetch into maturing corn or soybeans.  Another option is to plant it very late (mid-late November) and hope it doesn’t germinate until the soil warms up in late winter-early spring.   I don’t think people realize how versatile hairy vetch can be.  In the northern areas suited for field peas (see above) hairy vetch could be managed as a summer annual. [I have seen hairy vetch flower, drop seed which stays dormant during a hot dry summer – Dave’s EMPHASIS HERE – this is why I caution growers about Hairy Vetch.]  When the weather cools down in late August the vetch seed sprouts.  It is still warm then through September and early October with temperatures similiar to the Great Lakes states and New England in the summer.  So why couldn’t vetch be planted in early summer in these areas?

Years ago I planted hairy vetch in April between wide rows of vegetables just to see what would happen.  I remember lots of growth by July, despite a hot dry summer. The soil under the vetch was cool and moist.  The vetch did not grow enough to fix much nitrogen by May but it may have fixed enough nitrogen for mid-summer planted crops.

In 2012 I will plant hairy vetch and other vetches (purple) in the spring and record how they do.

Finally, new cultivars of hairy vetch come out which may have promise.  I will try a new variety called Purple Bounty, which is supposed to mature two weeks earlier but with less winter hardiness.

 

Nutrient Scavenging Cover Crops – How much good are they doing? It depends.

Meet the Cover Crop Scavengers

Over the years I have worked with cover crops I have recommended that producers use “scavengers” like Annual Ryegrass, turnips, cereal rye,  winter barley, oats,  and cover crop radishes.  These cover crops do a very good job of capturing excess nitrogen and other nutrients and keeping them from reaching the ground water or running off with surface water.  When the nutrients are scavenged they are available for the subsequent crop.

Most of these scavengers are “luxury consumers” of nitrogen and a few of them are also “luxury consumers” of phosphorous.  These are ideal to use on land where manure is applied.  They also work very well when grown with a legume like crimson clover, hairy vetch, chickling vetch, and Austrian winter peas.

However, if  limited amounts of nitrogen are available how will these scavengers perform?

The answer: not as well.

My answer is subjective but based on observations that I will show you via some photos.

 

Observation 1

It is easy to see where the manure was knifed in in this field. But how much more N is being taken up where it is darker green? We'll be doing tissue tests soon to determine that.

The first observation is where hog manure was knifed in after wheat had been harvested. The photo shows that the cover crop (Annual ryegrass and Appin turnips) looks considerably darker where the manure had been applied.  We will soon be taking tissue samples to see what difference there is in the amount of N, P, and K are in the plants.  We also anticipate a future post showing a root pit view of the root growth difference (if any).
 
 
 
 

Observation 2

The "yellow" strips are pretty obvious in the cover crops in this seed corn field. It is not obvious where the corn rows were but I expect the lighter strips are above where the corn row had been.

The next observation comes from a seed corn field in north western Indiana near Demotte in Jasper county.  The main area of difference in N uptake is found where the male corn rows had been cut out this summer after the female rows had pollinated.  The difference is color was not as dramatic as it was in the previous situation but there was a clear difference in color and the amount of growth (considerably more developed) of the cover crop.
 
 
 
 

Observation 3

The left half of this photo had 35#/acre of N but had no legume to feed the radish. The right half of the photo shows the significant color and growth difference when radishes are grown with crimson clover (and the 35# N/acre).

The next field is near Edgerton in NW Ohio.  This field had three different applications being trialed.  One area had a crimson clover and GroundHog radish mixture, another area had an Austrian Winter Pea and GroundHog Radish mixture.  In between these mixtures was a strip of Tillage cover crop radishes with no legume but with around 35 units of nitrogen applied (the ~35 # of N was applied across the whole field).  If you attend many cover crop meetings you will hear speakers tell you to apply 35-50 units of N on radishes if they are sown without a legume or without manure applied.  After seeing this field I believe we are underestimating what kind of N we need to apply for “best” results as the radish only strip had considerably smaller radishes with much less tuber growth and more “yellow leaf”.    The area with the crimson clover/GroundHog Radish Mix was by far the darkest green and had the largest radish growth.  However, even though the peas did not look as impressive as the crimson clover, the radish growth was significant and much darker green than the radish area grown without any legume.

Observation 4

Not only does the crimson clover add nitrogen to the soil it also greatly enhances the soil structure. The soil on the left came from where there was only radishes planted. The soil on the right had crimson clover and radishes mixed together.

Another observation from this field was that where the radishes were grown with the crimson clover the soil had a much improved structure over the soil where only radishes were grown.  The massive amounts of crimson clover roots (with an exceptional amount of nodules on them by the way) gave the soil a much better texture.  See a very descriptive video here.  These soils are “Williams County Clays” or “NW Ohio clays” and are well known for their tightness and poor drainage.  As the farmer Ryan Sanders said after seeing the results of this experiment… “I will never plant radishes alone again.”