Fungi could be the next ‘bio-fertilizers’

Posted May 11, 2015 by Tim Sandle
Biologists are proposing that a common soil fungus could be a candidate as a ‘bio-fertilizer’, replacing the more harmful phosphate based chemicals. In a study on rice crops, the fungus has triggered improved root growth.
Fertlizing Corn
A farmer applying fertilizer to his corn crop
Lynn Betts
The type of fungi in question are mycorrhizal fungi. A mycorrhiza is a term for a symbiotic association between a fungus and the roots of a plant. There are many different species that engage in this activity.
The study has shown that the fungi enable better root growth for rice plants. This is because the fungi facilitate the plant absorbing more nutrients. Here the fungi extend into the soil (via the hyphae, which act like tendrils) and pass some of the nutrients absorbed back to the plant. One of the nutrients pumped back into the plant is phosphate, which is essential for plant growth (and is the basis of many commercial fertilizers.) This process has been termed “mycorrhizal symbiosis.”
The effect is seen for rice grown dry, rather than in a paddy field. Around 40 percent of the rice in the world is grown in soil.
This has led a research group, based in Cambridge (U.K.), to propose that if the fungi are encouraged to grow in soil, then this would negate the need for artificial chemical fertilizers to be used. This would save costs and be better for the environment, in that phosphate would not need to be mined at the same quantities. It also stands that the world’s phosphate supply could be run down within the next 50 years.
The use of the fungi would benefit rice, wheat and maize most greatly of the various cereals in the world. As well as allowing the fungus to flourish, researchers argue that the best crops can be selected too. Here it is possible to breed crops with the best possible root architectural and symbiotic properties. This means having thick roots with long, thin branches coming off the main trunk.
As an extension of the research, mycorrhizal fungi could be key ingredients in 'bio' plant foods used for houseplants.
The findings have been published in the journal Proceedings of the National Academy of Sciences. The research paper is headed “Transcriptome diversity among rice root types during asymbiosis and interaction with arbuscular mycorrhizal fungi.”