Adapting microbes that dramatically increase crop yields while reducing demand for fertilisers and pesticides through selective breeding or genetic engineering could be cheaper and more flexible than genetically modifying plants themselves, says an author of a report.
Microbes, such as beneficial bacteria, fungi and viruses, could be produced locally for smallholder farmers to significantly improve food security and incomes in developing regions, believes Ann Reid, director of the American Academy of Microbiology and co-author of a report published by the organisation last month (27 August).
'Genetic modification of crop plants, which has seen a huge investment, is closed to all but the biggest agricultural companies,' she tells SciDev.Net.
'Optimisation of microbes could be done at the level of the local community college and is much more obtainable for a smallholder farmer.'
Her comments echo the findings of the report — the product of an expert meeting in 2012 — which underscored the significant impact microbes could have on food production by increasing crops' absorption of nutrients, resistance to disease and environmental stresses, and even improving flavour.
As well as to accentuate naturally occurring traits such as the secretion of pest-killing toxins or nitrogen-fixation, the modification of microbes is often needed to allow them to be grown in large numbers out of their natural environment.
For example, researchers in Colombia could only produce large quantities of a fungus that improves the nutrient absorption of cassava once they bred a strain of that fungus that was capable of growing on carrot roots.
Recent technological developments in rapid DNA sequencing, imaging and computer modelling can help provide further solutions, as well as building a greater understanding of the complex environment that microbes themselves need to flourish, the report says.
These advances raise the possibility that, within two decades, microbes could increase food production by a fifth and reduce fertiliser demands by the same proportion, it finds.
But to achieve this ambitious goal, the research community must engage in curiosity-driven basic research, develop even cheaper sequencing techniques, and establish a process to move discoveries from the lab to the field, it says.
Reid adds that, unlike genetic modification, which requires farmers to regularly buy improved seeds, microbes may be able to stay in the soil indefinitely.
But larger universities are still needed to drive more-complex areas of investigation, which inevitably requires funding, she says. 'We wanted to get the word out that this could be a big-bang-for-your- buck area for funding agencies.'
Matteo Lorito, a professor of plant pathology at the University of Naples, Italy, agrees that sophisticated research centres must be involved in identifying and selecting suitable microbes and techniques.
But once this groundwork has been done, growing microbes will require as little as a fermenting tank, he says.
The impact of this approach is already being seen in areas such as Honduras, where melon yields have been improved by 15 per cent by applying a fungus that boosts the plants' defence mechanisms.
Other crops such as maize, tomatoes and wheat could see rises in production of more than 50 per cent from such techniques, he believes.
But Ken Giller, professor of plant production systems at the Netherland's Wageningen University, says that much more work needs to be done, particularly on how to get the microbes into the soil, before farmers will benefit, he says.
'Molecular biology has been incredibly important in understanding biology in general, which has helped when thinking about solutions [for food production],' he tells SciDev.Net.
'But in terms of the manipulation of these processes to make an impact in the field, we have yet to make any great inroads.'