Landrace cover crop for a special purpose

[gilbert]

If I don't stop thinking up new projects, I'll be in trouble! 

I need a cover crop, or mix of crops, which will overwinter, grow rapidly in the spring, fix nitrogen, cover the ground, and fade back in June as I plant warm weather crops. Then, it has to come back to life in September as the warm weather crops fade, either from tough seeds or as a perennial, well enough to thickly cover the ground going into winter. 

So far, I've found a few grasses which are said to die back in the summer even if watered. However, most legumes do not do this. Subclover can, but it is not winter hardy here. Vetch might reseed, but it is rather tall and tangling; I'd like something more mat-like for the shoulder seasons when it has to co-exist with the crop. And I'm not sure if it will reseed well in a hot dry autumn. 

Since this does not seem to exist, I could try to breed it! (If it exists, let me know.)

The plan would be to mix up lots of varieties of vetch and subclover, as many as possible, and possibly some cross comparable species, and plant them all together. Then, over each summer, I'd plant a smother crop of buckwheat. This would do two things. First, it would crowd out the summer weeds over time. Second, it would help to select for plants that went dormant as seeds or crowns; plants that kept trying to grow would be likely at a disadvantage. In the winter, I'd have to park a low tunnel over the beds to keep them from freezing out before the genetic lottery got going. Over time, I could reduce the protection level. 

A related project would be a legume that could be covered with plastic or paper mulch, go dormant, and quickly re-emerge to cover the soil when the plastic is removed. Again, it might exist to some degree, but I could certainly select for this trait. 

[reed]

They are not really cover crops at least not in the normal sense but I have been doing something kind along those lines with radishes and turnips. Of course they don't fix nitrogen but I'm told they release it when they rot. I only harvest flower stalks and seed pods eat. Been at it for about four years now and they are settling in pretty good as self sustaining "weeds" that cover, till and improve the soil while at the same time making for some fine salads. I'v also come to greatly appreciate my wild purslane for similar uses.  

[oxbowfarm]

I'd try white clover. It doesn't die back in the summer, but it stays low and would be overtopped by your crops, which I assume you would still be watering? Elliot Coleman used to advocate using white clover like this. Maybe he still does, I don't keep track.

[steve1]

Very 'One straw revolution' with the white clover. From memory Fukuoka knocked back the clover before planting crops by flooding his fields for a week.
His rice yields on non flooded fields were as high as anywhere else in Japan. I guess if you have enough water for the clover and crops it might work, you might even just be able to mow the clover to knock it back. My guess is that it might take some time to find varieties that perform really well in this situation, but would probably be well worth it.

[reed]

White clover would be great. I have a lot of it in the yard but have never succeeded in getting it established in the garden. I guess it just can't hold on with the veggies, at least not in my garden.

[keen101 (Biolumo / Andrew B.)]

Jan 13, 2018 19:45:30 GMT -5 gilbert said:

I need a cover crop, or mix of crops, which will overwinter, grow rapidly in the spring, fix nitrogen, cover the ground, and fade back in June as I plant warm weather crops. Then, it has to come back to life in September as the warm weather crops fade, either from tough seeds or as a perennial, well enough to thickly cover the ground going into winter. 

I doubt you will be able to find or breed something that fits all of your requirements, perhaps some. But good luck either way.

This reminds me of that permaculture farm documentary where that guy in Wales or Scotland or whatever wanted to farm his cows in a natural sustainable manner where the cows did not need supplemental feed in the winter but the cows would not erode the soil. His solution was to create biodynamic multi-culture of natural grasses, tweed, and other plants to create a thick mix. It worked!

See part 19:33 in the video below:

topdocumentaryfilms.com/farm-for-the-future/

Here there is a small short type of drought and cold tolerant sage that is growing right now in my garden. There might be a few other plants too. The best i've seen are the bulb based plants like the purple hyacinth flowers or chives. Perhaps snow drop flowers would work well. But the grape hyacinth flowers grow super fast in cool early spring weather and fall weather and any weather in between snow storms when it warms a bit. But it does not die back and it spreads a lot. but the bulbs are easily tilled and other things planted in their stead. The short sage is easily torn away. Other plants like the various clovers grow here sometimes. There is one clover that is currently green in my dead watermelon patch. The shamrock comes to mind as well. The catnip has also become a cover crop on it's own.

I'm personally thinking of someday having a home where i either refuse to plant useless ugly grass in my yard or rip out all the former existing grass lawn and plant it entirely of grape hyacinths or chives or both as they are green in the winter and all year round and need less water than grass so they don't get all ugly brown in the summer.

[ferdzy]

Yeeeeaaaahhhh, maybe not on the white clover. We tried it one year and it did well. VERY well. So well we had to rip it out. It's perennial, and it grows pretty high if it isn't mowed. Just a note of caution there. Can see it some applications but they will need to be carefully thought out.

[gilbert]

The white clover might work; I've seen it done other places. The potential problem is that it might steal water from the crops. I would be watering, but water is a scarce commodity here. I'm using city water, so it is fairly expensive.

I suppose the first step would be to do a side by side comparison with clover and without.

The Fukuoka reference is relevant; he needed to suppress the clover somehow to allow the crops to get ahead. I'm wondering if lengthening days or increasing temperature couldn't do this for me.

Subclover would be perfect if it would overwinter here, I'd think.

[oxbowfarm]

Another option might be black medic, although I don't think that there are any legumes that are going to actually exactly meet your criteria, especially with regard to not competing for water in summer. Black medic wouldn't grow tall enough to compete for light though. I don't know if you can buy black medic seed, its pretty much considered a lawn weed.

[gilbert]

Black medic grow pretty well in lawns here. On the other hand, it doesn't produce much biomass either. I wonder if it fixes much nitrogen compared to the clovers. I think it is an alfalfa relative.

Any cool season annual legume wouldn't compete with warm season crops; the trick would be to get reliable reseeding with hard seed for the fall.

[keen101 (Biolumo / Andrew B.)]

What about lupin? Lupin should be native to the dry areas here. I tried growing it once. And it is a legume like you want and might die in the summer like you want, not sure.

[gilbert]

What about lupin? Lupin should be native to the dry areas here. I tried growing it once. And it is a legume like you want and might die in the summer like you want, not sure.

I looked into them a bit. It sounds like they tend to bloom a little too late; so the perennial ones wouldn't die back in time, and if the annual ones were terminated early, they wouldn't have produced seed for the spring. Also, it didn't sound like they would germinate and start in the fall.

But there are lots of different lupines. Maybe I should do some more research. Or maybe they would be a good breeding project for this. It would certainly be beautiful. It is too bad they tend to be poisonous. 

This sort of idea has been at the back of my mind for a long time; some sort of Fukuoka type system where a minimum amount of work at the leverage points would produce a high yield. Most low work permaculture type systems are just too low yielding, or depend on trees; and Colorado is not friendly to trees. 

[oxbowfarm]

The more I think about this, there are all kinds of low growing perennial legume species out west. Locoweed and/or milkvetch jump to mind, something like woolypod locoweed or Lambert locoweed? You definitely cannot buy seed for those I don't think.

[gilbert]

I've done some more research on Lupines. They look rather promising. Some species are winter annuals; many have hard seeds which need to weather in the soil before sprouting; they tend to tolerate cool weather; and they fix nitrogen. So far, I haven't found a winter annual with hard seeds that could overwinter here. But, lupines tend to cross easily with one another. Maybe a good first step is to set up a lupine garden of the dozen or so native species.

Also, non-bitter types have been developed as food and fodder crops, which could stack another function.

[Joseph Lofthouse]

Jan 19, 2018 14:10:04 GMT -5 gilbert said:

non-bitter types have been developed as food and fodder crops, which could stack another function.

The supposedly non-bitter type that I grow is incredibly bitter.