- 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).
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 “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.
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.
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.
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).
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.
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 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).
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!
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.
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.
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.
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.
- 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.
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.
- 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.
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.
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.
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.
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).
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.
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.
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.”
Planting Cover Crop Radishes with Wheat – A Growing Practice
Cover crop radishes planted with wheat at seeding time?
Last year I posted about how farmers in NW Ohio are seeing increases in wheat yields by 4-7 bu/acre by planting 2-4# of cover crop radishes in with their wheat seed. In the fall of 2010 there were more acres of wheat planted in Indiana, Ohio and lower Michigan than in many years before, and several of those acres had radishes planted with them with the hope of increasing yields.
Several test plots were planted as well. Unfortunately, the seed was planted into very dry soil and it did not rain until late October or early November so the radishes grew very little (if at all). So the grand “radish seed planted in with the wheat seed” experiment was pretty much a flop in 2010 in the eastern Corn Belt. However, I heard reports from Oklahoma and New York that claimed to see value in this practice. By the way, 2# per acre is plenty. 4#/acre is too much seed.
How to Mix Cover Crop Radish Seed with Wheat Seed
As I have shared about this potential practice around the Midwest I often-times get the question, “How do I mix the radish seed with the wheat seed?”
I first mention the “coffee can and paddle” approach of adding the seed. As you fill the drill add some radishes and use a paddle (or even a tree limb) to stir it in. With that approach I usually get a confused and almost angry look from producers that think I am mocking them (Seriously, I am not!).
Since most farmers are more sophisticated than that I recommend adding the radish seed to the wheat seed at the seed house. Then I get angry calls from the wheat seed suppliers about adding a “weed seed” into their bagging system!
So I have concluded that the easiest way (and the way to recommend that will not get me in hot water) is to add the radish seed with the fertilizer that will be applied just before or after the wheat is planted.
I’m open to suggestions. If any of you do this differently will you please help out our fellow wheat producers? Thanks!