Soil researchers at the Agriculture Canada research station in Alberta have isolated a naturally occurring fungus, Penicillium bilaji, which makes phosphate soluble so that it can be more easily absorbed by plants.

Currently farmers must add up to ten times as much phosphate as is actually needed, because as the fertilizer lies in the soil it reacts with calcium, iron and aluminum and becomes unavailable to the plants. Several other microorganisms are known to have this phosphate dissolving ability, but none have the ability to work as efficiently or as long as the fungus isolated by Reg Kucey. The relative of the fuzzy green mold that grows on fruit has both the ability to stop phosphate fertilizers from deteriorating into insoluble compounds and to dissolve natural phosphates such as rock phosphate.

This could be a real boon to farmers in the developing countries who cannot afford commercial phosphate fertilizer but often have access to natural deposits of rock phosphate.

Kucey does not fully understand the mechanism by which the fungus dissolves the phosphate, but thinks that the organic acids produced as a by-product of normal metabolism attach themselves to metal ions on the insoluble phosphates. This allows the phosphates to dissolve into the soil water, ready for the crops to use.

Initial tests by a Canadian corporation have proved successful. Crops treated with the fungus did equally well as crops grown with monoammonium phosphate, a commercial phosphorous fertilizer. Further tests are presently underway.

New Scientist 1988, 118(1616):51