permaculture

["Lawrence F. London, Jr." <venaurafarm@bellsouth.net>]

On 6/8/2012 11:10 PM, Lawrence F. London, Jr. wrote:
> On 6/8/2012 5:33 PM, Jason Gerhardt wrote:
> > Buckwheat cover crop is a notorious phosphate scavenger. If your climate
> > permits, bring this into your rotation.
> I would guess tall sweet clover too. I have both white flowering and
> yellow growing on my property, I have encouraged it since I discovered
> it growing in 1978 when I bought my land. It is rare to find it growing
> wild these days. Some of my plants are now 7' tall.

http://scholar.google.com/scholar_url?hl=en&q=http://www.bashanfoundation.org/hirsch/hirschroots.pdf&sa=X&scisig=AAGBfm2GBdstkXVQl098g8WMsQywXTpMZA&oi=scholarr

Roots and Their Symbiotic Microbes:
Strategies to Obtain Nitrogen and
Phosphorus in a Nutrient-Limiting
Environment

Michelle R. Lum and Ann M. Hirsch*
Department of Molecular, Cell and Developmental Biology and Molecular 
Biology Institute, University of California, Los Angeles,
California 90095-1606, USA

ABSTRACT
The association between Rhizobium and legumes
and that between arbuscular mycorrhizal (AM)
fungi and most land plants display a remarkable
degree of similarity. Both events involve the recognition
of, entrance into, and coexistence within
the plant root, with the development of a specialized
interface that always separates the two partners
and at which nutrient exchange occurs. Molecules
produced by rhizobia during the early stages of the
symbiosis are related to fungal chitin, and the
plant responds to both microbes with an increase
in the production of flavonoids, which may assist
in recognition and development of the symbioses.
Many of the same plant genes are up-regulated
in the two symbiotic pathways, and notably plants
that are Nod) are often defective in the AM association
as well. However, there are a number of
differences between the associations, and these are
important for understanding the relationship between
the two symbioses. The Rhizobium and AM
symbioses will be compared and the question of
whether the nitrogen-fixing association evolved
from the much more ancient AM symbiosis will be
discussed.
Key words: Rhizobium; Legume; Arbuscular mycorrhizal
fungi; Symbiosis