Gilbert Fritz wrote:
One of my points was that I don't think plants are at the mercy of soil chemistry, so long as organic matter and fungi are present. Steve Solomon is right about this in his tilled beds, not about a hugelkulture.
Gilbert Fritz wrote:Also, I should have said that an annually tilled garden can not make use of fungi, because they will not be present (will get shredded). Annuals in a sheet mulch would probably do much better at this.
Gilbert Fritz wrote:I always try to integrate conflicting views, instead of sticking to one and throwing out the other. This is my feeble attempt to do this here. I think, in most scientific conflicts, that both views are at least partly right, just in different contexts and different ways.
John Saltveit wrote:This is a great discussion! Annuals do have fewer exudates to encourage the soil food web.
The list of specific compounds released from roots is very long, but can generally be categorized into organic acids, amino acids, proteins, sugar, cellulose, mucilage, phenolics and other secondary metabolites...The cocktail of chemicals released is influenced by plant species, edaphic [of, pertaining to, or influenced by the soil] and climactic conditions which together shape and are shaped by the microbial community within the rhizosphere. There is still very little known about the role that a majority of the compounds play in influencing rhizosphere processes. A growing body of literature is beginning to lift the veil on the many functions of root exudates as a means of acquiring nutrients (e.g. acquisition of Fe and P), agents of invasiveness (i.e. allelopathy) or as chemical signals to attract symbiotic partners (chemotaxis) (e.g. rhizobia and legumes) or the promotion of beneficial microbial colonization on root surfaces (e.g. Bacillus subtilis, Pseudomonas florescence) (Bais, Park et al. 2004).
Adam Klaus wrote:I work to encourage fungal populations in my garden soil by innoculating my compost with native mushrooms, and spraying horsetail biodynamic fermented tea.
Jennifer Wadsworth wrote:Humans and other animals excrete phosphorus in urine and manure. So another way to add phosphorus back into the soil is to use these elements within the system...certainly permaculture is all about creating a no-waste system where everything gets cycled through and used in some way.
Jennifer Wadsworth wrote:Humans and other animals excrete phosphorus in urine and manure. So another way to add phosphorus back into the soil is to use these elements within the system. I don't know Steve's work so I don't know if he addresses this, but certainly permaculture is all about creating a no-waste system where everything gets cycled through and used in some way.