Figure 1.

Systematic diagram of P solubilization by fungi used in the biological control of nematodes. (a) Nematodes can be parasitized and predated by (in clockwise order) trapping fungi, egg-parasite fungi, special device-producing, or toxin-producing and endoparasitic species. (b) Compounds produced by fungi. (c) Chemical reactions of P in soil, binding with elements such as calcium, iron, and aluminum that can then be mineralized or solubilized by the NF compounds. (d) Roots absorbing negatively charged orthophosphate ions.