Plant Cover Crops

Learning about the benefits of planting cover crops.

field peas

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

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

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

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

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

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

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

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

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

Oats

Advantages

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

Disadvantages

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

 

Field Peas or Austrian Winter Peas

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

Advantages

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

Disadvantages

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

 

Crimson Clover

Advantages

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

Disadvantages

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

 

Cowpea

Advantages

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

Disadvantages

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

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

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

Cover Crops 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.