Mycorrhizal fungus may be bio-fertilizer for crops: study

A common fungus could be used as "bio-fertilizer" in the future, replacing mined phosphate which is now depleted to the point of an impending fertilizer crisis, according to a report recently released by the University of Cambridge.

Researchers from the University of Cambridge found that the interaction of roots with a common soil fungus changes the genetic expression of rice crops, triggering additional root growth that enables the plant to absorb more nutrients.

In addition to causing extra root growth, the mycorrhizal fungus also entangles itself with crop roots at a cellular level, blooming within individual plant cells. The fungus grows thin tendrils called hyphae that extend into surrounding soil and pump nutrients, phosphate in particular, straight into the plant cells, researchers said.

Plants "colonized" by the fungi get between 70 percent to 100 percent of their phosphate directly from these tendrils, an enormous mineral boost which may eventually reduce farmers' need to use phosphate fertilizer, said researchers.

Finding a replacement for mined phosphate is a critical problem as not only is the resultant fertilizer a pollutant, but the big phosphate mines are expected to run out in the next 30 to 50 years.

Mycorrhizal fungi are extremely common in all soils around the world, and are an ingredient in many organic plant foods found in domestic garden centers, but have yet to be used for industrial agriculture.

"Plants monitor their own nutritional state. If a plant has enough phosphate, it will not allow the fungus to enter the root ... We are working on ways to circumvent this blockage so we can allow symbiosis to contribute in agricultural practices in better developed countries," said Dr. Uta Paszkowski from the University of Cambridge who co-authored the research paper published in the journal Proceedings of the National Academy of Sciences. Endit