Originally Posted by WannaBeOrganic
What you guys wrote reminded me of something I read about a year ago. There's a resaerch that has a website where she publishes gardening myths. One of them was about phosphorus and mychorizae. Basically lack of P results in shallow roots, shallower roots make the plant secrete an acid that attracts mychorizae to colonize on the roots to help provide P.
Found it. Seems appropriate it's titled The Myth of Beneficial Bone Meal
So what are you saying? Plants are better off without the Mycorrhizae?
What do these 2 paragraphs, from your link, mean?
"Why does the myth of phosphorus-induced root stimulation persist? The answer probably lies in the effect phosphorus fertilizers have on mycorrhizal relationships. When plant roots are in low phosphorus environments, they exude organic acids from their root tips. These acids allow mycorrhizal fungi to penetrate the roots and form the networks that assist plant roots in taking up water and nutrients. Mycorrhizae are particularly adept at extracting phosphorus from the soil.
If phosphorus levels are too high, however, the roots do not exude the organic acids and mycorrhizal connections do not form. This forces the plant to put more resources into root growth to compensate for the lack of mycorrhizae. So in a sense phosphorus will increase root growth – but at an added cost to the plant. The resources expended by the plant in growing additional roots to take the place of mycorrhizae are not available for other plant needs."