TL;DR: New research shows that biochar made from phosphate-poor feedstock encourages much more symbiosis with mycorrhizal fungi, compared to biochar made from phosphate-rich feedstock, which encourages very little mycorrhizal symbiosis.
Very interesting and a strong hint that sustainable farming should try to enhance the natural composition of the earth. Phosphate fertilizer works but the mycorrhizial fungi will leave over time. This leads to earth where you have to use Phosphate to grow plants. I am allways facinated by the intricate relationships in nature.
I recall reading that someone discovered that a primary reason the amazon forest is so fertile now is that it has a huge stock of biochar left by the mayan civilization.
Either they knew what they were doing, or it is a happy effect of all the cooking fires they made, from the char they left in the area.
