Cover crops like these are amazing in their ability to improve soil health and
provide lots of other services.
But to do these good things they need to be planted correctly and managed carefully
and having the right equipment is critical
I'm going to be talking about some innovative cover cropping equipment
that we've been developing and dreaming about developing
but let me start off with a story of my first experience planting a winter cover crop
in the organic research farm that I started managing several years ago
The soil here was in bad shape and needed lots of cover cropping to turn it around
So when I planted that first cover crop this is the grain drill that I used
And I remember how good it felt as I pulled that drill back and forth across the
field planting the cover crop and thinking about all the good things that I was doing for the soil
Now after I'd planted about half of the field
I figured I better go and check to see how much seed was left in the hopper
Well, unfortunately one side was completely empty and I had no idea where in the field the seed had run out
Now I didn't want my first planting to look like I didn't know what I was doing
You know, with big gaps where the weeds would grow
so I reloaded the grain drill with seed and I replanted the whole field again
I've learned a lot about cover crops since then and I'm now much more
comfortable with the various features on standard planters
but I've also come to realize that these planters and a lot of the other tools that we use to manage the cover crops
have their limitations and aren't always well-suited for the high value cropping systems that I work in
and I think this is part of the reason that cover crops aren't as widely used as they should be
So the novel system and equipment that I'm going to be focusing on
involves growing cover crops on beds
in the same row spacing that we use for many of our vegetables
Now there's lots of potential advantages of growing cover crops on beds
and I'll explain some of those after I show you
the modified planter that we used to plant that
So this precision belt seeder works really well
with round pelleted seeds
And it's been the standard planter for most of the lettuce industry for more than 50 years
It's a great planter because it accurately spaces individual seeds within a row
But we don't need that level of accuracy with a cover crop
and it wouldn't make economic sense to pellet irregularly-shaped cover crop seeds
The pelleting process is pretty expensive
So we remove the seed metering units
and we added these multi-purpose hoppers
that deliver the seed right down to the bed where it's needed.
Here we are planting the rye cover crop in two lines on four beds
and here's the field nine days after planting
Now the first potential advantage of cover cropping on beds
is that we use about sixty to seventy percent less seed
than with a standard planting arrangement
With a standard cover crop planted say with a grain drill
there would be several more seed lines per unit area
and this is important to shade the soil quickly and suppress weeds
but with a bedded cover crop we manage the weeds differently
So here we are rotary hoeing the cover crop
to uproot weeds that aren't as deeply rooted as the cover crop
We then like to follow this with a standard vegetable cultivator about a week later
and this helps to take out remaining weeds that may be in the furrow bottoms
or on the bed top and might have been missed by the rotary hoe
The cover crop then fills in the bed top and shades the furrows giving us a nearly weed free cover crop
that's still extremely productive
Now if the weather cooperates
we can take out several weed flushes during a single winter
and this really helps to reduce the weed seed bank
When the cover crop needs to be mowed
there are some real benefits to having it on beds
rather than having it in a standard unbedded arrangement
The wheel tracks of the tractor in a standard cover crop
push down the cover crop in front of the mower
and this can leave long unmowed strips through the field that are difficult to incorporate into the soil later
Now in contrast with a bedded cover crop
the wheels run in the bare furrow bottoms
and this allows us to cut the cover crop into smaller
and more uniform pieces
and also mow the cover crop closer to the soil surface
Now another potential benefit to cover cropping on beds
is that it allows us to control the growth of the taller cereal component in a legume cereal mixture
For example, with this rye-vetch mixture
the rye starts to flower before the vetch
and we can actually mow the rye seed heads off
in the upper canopy to prevent them from setting viable seed
and then let the vetch vines get a little bit more light
and grow a little longer to potentially fix more nitrogen
Let me now share some ideas of some innovative cover crop management strategies
and equipment that I've been dreaming about developing
Earlier this year I wrote a paper that addresses this complicated
question about cover crops and sustainability
And in that paper I described several different cover cropping strategies.. some new ones
probably the most novel idea involves extracting nitrogen rich juice from cover crop shoots
to use as a liquid fertilizer in subsequent vegetables
You might want to check out that paper and learn some more about that interesting idea
The juicing strategy involves harvesting cover crop shoots from beds
using a forage harvester like this
it would actually be pulling a trailer to catch all the harvested shoots
and then they would be processed
And as we've been experimenting with his forage harvester
I've been wondering about another way to use it that doesn't involve juicing
and this idea came to me when we were trying out the mower or the harvester after some broccoli
What really impressed me about it is that it cut the broccoli right at the bed top
and then lifted the residue off the bed top leaving it really clear
The bed top was actually so clear that it looked like you could plant your next vegetable right into it with almost no tillage
So we're going to try modifying the hood of this forage harvester so that the finely chopped material
that's pulled off the bed
can be channeled back down and into the furrows between the beds
leaving the bed top free of residue
We could then lightly strip-till the bed top if we needed to
and then plant our next vegetable and leave the residue in the furrow bottoms
as a mulch where it would decompose slowly and then provide a lot of other benefits
Now as you've probably figured out I like Legos
They inspire kids to be creative and also adults too
and as we develop new tools for cover cropping
I often feel like...
a kid with a lego set
it's a lot of fun seeing what you can come up with
So stay tuned as we continue working on innovative cover cropping equipment and strategies
I think these have got a lot of potential to increase cover crop adoption
and make the systems that I work in here far more sustainable
take care