Dr. Elaine Ingham has been talking about a novel approach to cover-cropping, using a diverse selection of low-growing (1-3 inches tall), perennial plants as an understorey, into which narrow strips are tilled and then sown/planted into, giving the crops sufficient room to establish.
In this manner, she says, the majority of soil surface remains protected from weathering, and the supply of root exhudates to the soil microbes is maintained, enabling them to remain minimally affected by the cultivation. Likewise, the plants that are best adapted to the weather conditions in a given year are the ones that end up being more prominent in that year.
If you click on the below link you can listen to or download the relevant excerpt from our interview with her:
Elaine Ingham on perennial cover crops
(Click to listen, right click and 'Save Link As' to download)
Sounds wonderful in theory doesn't it?
The main question then, is which plants would be appropriate to use in our climate, and likewise with different soils, topographies, rainfall, etc.
What I've managed to glean up until now is:
20-25 species of plants, with an emphasis on broadleaved, winter-hardy and native species
The SFI website lists successful combinations of plants for the northern US; some of which have potential relevance for us in northern Europe.
Plants I recall Elaine mentioning as possibly being appropriate in Britain include:
Docks (low growing) - does anyone know what Rumex species this could be?
From the lists, these also seem promising to me:
Creeping St John's wort
Whilst a few other ideas a couple of friends of mine and I have had include:
As far as existing research is concerned, Elaine mentioned some done at the Rodale Institute before she left, and some done by Jay Fuhrer and Gabe Brown. So far I have yet to find anything in print relating to this particular approach; the latter 2 gentlemen seem to be talking about annual cover crops in what I've seen of their work thus far.
I imagine that a good asset with this endeavour would be someone who knows about establishing wildflower meadows. I've been looking at native seed merchant websites, and this one, for example, categorises plants by height, but it doesn't have a very good selection, and some of them aren't particularly low either. So something along these lines but more extensive and precise would be useful. Of course observing the native flora in an intact ecosystem is another.
I feel that it would be good if we could start investigating these things, as the sooner we stop destroying our soils, the better! Therefore I welcome input from others here, and will distribute this in other places for wider perusal and report back what I learn. Please feel free to do the same yourselves.
A related field of inquiry is pasture cropping, which I've yet to determine if it is something that would be practicable in Britain. But that is another matter...
Below are some additional things that have come to my attention since making the original post:
1. There is a term for the type of tillage involved, it is 'strip-till'.
Here is a short video demonstrating its use. Obviously I'd hope we could both till and sow/plant all in one pass.