Hi,
I have watched a few youtube movies about Dr. Elaine Ingham and soil food web. In there, she says that, if we have lots of life in soil, we should have great plants above, too.
That's something we all know, for sure, however, I was intrigued about her way of achieving this.
She talks about perennial cover crops, plants that are evergreen if possible, with deep roots, and small height above the ground. This way the bacteria & fungi is always fed.
Also, these deep roots, will create good soil deep underground, decompacting it.
There is a list here: http://www.soilfoodweb.com/Cover_Plants.html but it is about low grow plants.
Is there a list somewhere of deep rooted plants that can go through compacted soil, preferably perennial too?
Does anybody know a few plants that are suitable for this job?

thanks.

Low growing, perennial, nearly evergreen, covered in flowers for most of the year, grows by runners that send down taproots: frog fruit http://www.wildflower.org/plants/result.php?id_plant=PHNO2

I'm still experimenting with this, but it didn't seem to hurt the saffron to grow under a layer of this. My collards and roses look happy. Everything else but the rosemary is too young to tell or lived the expected lifetime. Rosemary is a special case, as I somehow always manage to kill it no matter what I try. I haven't been having good luck getting seeds to germinate in the middle of the frog fruit, but I'm not the best about keeping steady soil moisture. It was a thin covering during the last planting period. I'd like to try again next season now that the thicker cover of frog fruit may help seal moisture close to the surface. If that doesn't work I'll go the other direction and pull back larger open areas when I plant seeds.

Here's an update on my perennial cover crop project. I have been at a loss as what would be my first step. When I wrote the initial post, I thought that planting the right perennials, their deep roots would break the compacted soil. Now I am not so sure any more.
For example, here:    , she says that if the roots do not run deep, then the nature tells us that we have compacted soil, and we need to address that problem. The solution is compost, and the micro-organisms in it. From other movie that I couldn't find to place the link here, I know she sais that we must inoculate the soil at compaction depth with that compost, and the life there would break it and give it structure so the roots can then grow below.
However, I know that the micro life in the compost cannot live without root exudates.
It's like that story, who was first, the egg or the hen?
Should I put the root first, then the bacteria and fungae would appear and flourish, breaking compaction along the way, and the root will go deeper and deeper, together with the life around it [that's something that I would prefer.]?
Or, I should first make compost, inoculate the soil with it, then add the root - from here videos it seems that most of us get the compost pile wrong, and we should be very scientific about that process?

Russian Comfrey is a permaculture all-star—specifically, the Bocking 14 variety.  It sinks a root deep into the soil, covers a significant amount of space when full-grown, its leaves are fantastic compost activators, and it comes back year after year.  Where I live, I cut it back about every second month, even in the winter. 

If you are not familiar with it, search on this forum and you'll find all sorts of threads and videos on it.

As for which to put down first, the compost or the plant, I would encourage you to put down a heavy layer of organic material of some sort—any mulch is good mulch.  I use hundreds of wheelbarrow loads of wood chips throughout my food forest/integrated orchard.  But any plant-based mulch will do—grass clippings, spoiled hay, manure, leaves or pine needles . . . or all of them.  Microbes WILL live in mulch, even without root exudates.  Any organic mulch will eventually break down, which is the basically the same thing as compost.  Fungi will thrive in a thick layer of mulch.

Best of luck.

As I understand it, compaction creates a toxic, anaerobic layer which roots will not penetrate.  They grow sideways instead.  Ideally you would break through the compaction layer, and introduce beneficial biology, at the time of planting or immediately before.  Depending on the depth of compaction and the size of the project, this could be as involved as using a deep ripper with tubing attached, or a simple handheld soil injector.  I've had some success pounding rebar through the compaction with a hammer, then dribbling compost extract down the hole; just be sure to check every few swings to make sure you can still pull the rebar back out.

The compost/tea/extract should have not only healthy compliments of bacteria and fungi, but also protozoa and beneficial nematodes; otherwise nutrient cycling will not happen.

Interestingly, Dr. Ingham lists some ground covers that many would shun as overly aggressive, like bugle and creeping Jenny.  These suit my situation just fine.  What works best for you will depend on your climate and your crop.

I am researching low growing perennials to plant as strips/paths in one of my fields in order to nurse beneficial microbes throughout the year. Doing so is an investment in time and resources, so I would like to avoid planting perennials that are too eager to spread from their strips into my annual rows. It's a fine balance of these qualities: competes against weeds but doesn't spread into adjacent beds, withstands foot traffic/occasional tractor tire traffic, thrives in full sun/part shade, etc. I live in the mountains of NC, a climate closer to the Northeast than the South (zone 6b). Elaine Ingham's list of low growing perennial crops includes some I would be wary of establishing so close to my annuals. Anyone able to shed any light on this?

Perhaps creeping thyme?  It's on Dr. Ingham's list, and although it will spread eventually, in my experience it does so very slowly.  The downside is that it hasn't - for me - created a weed-choking ground cover.  Some weeding would probably be necessary.  But it will provide protection, attract lots of beneficial insects, and of course feed the soil life.