Termites and ants boost crop yields
Rather than damaging crop yields, these insects have been found to enrich soil by more than one-third.
ANTS AND TERMITES HAVE long had a bad rap for stealing picnic food and chomping through house frames, but it turns out that their services are invaluable to Australian farmers.
New research from CSIRO and the University of Sydney has shown that, by performing an earthworm-like role in soil enrichment, the insects can boost crop yields in the dry areas of Australia's wheat belt by more than one-third.
"The sheer size of the effect is what is most surprising to me," says lead author Dr Theo Evans, from CSIRO Ecosystem Science in Canberra. "I didn't think it'd have such a huge impact - a 36 per cent yield increase compared to my expected five per cent."
The results suggest that ants and termites not only increase grain yields but can cut fertiliser bills and decrease the need for pesticides. "It's likely to mean decreased pesticide use, especially pesticide that is applied to the ground," Theo told Australian Geographic.
Ants and termites have a positive affect on crop yield
Enriching soil is traditionally an earthworm role, but, say the CSIRO scientists, in arid zones it's ants and termites that perform the important biological functions that worms do in the cooler and wetter zones.
These insects are able to re-colonise untilled wheat fields that have 'crop stubble', which they use for nourishment as they establish their underground nests. The activity helps more rainwater soak into the ground where plants need it most. The insects also increase the amount of nitrogen - a nutrient needed for plant growth - by a quarter.
The study, published last week in the journal Nature Communications, is the first of its kind to look at ants and termites in agricultural systems and is also the first to show that such insects have a positive effect on crop yield. It is possible that any 'dryland' farmland - non-irrigated agriculture - may benefit, Theo says. This includes wheat, oats, barley, rye, canola and perhaps, cotton.
"Poorer parts of the world which don't irrigate may be positively affected," he says. Theo sees potential benefits to swathes of marginal land in southern Africa, Brazil, Mexico and the Mediterranean, particularly "if the effect is true across broader soil types and across species."
He hopes the research will take the 'triple-bottom-line' approach - people, planet and profit. "It might pay the farmer economically, but it could be that by harnessing ecosystem services, we could be better off in every way,"
Insects boost farm efficiency
Farmer, Rohan Ford, whose property was used as field study site for the project, is buoyed by the results. "It's great news. I think it's a mindset - it's about understanding what chemicals you can and can't use, and how we can best use our machinery. The interesting thing, now the information is out there, to see whether we can get more funding to keep doing research into different soil types."
Next, the team is keen to look into the extent to which termites act as nitrogen fixers - agents that convert nitrogen in the air into a form that plants can use in the soil. "They definitely enrich the soil, but we'd like to know which species provide the most benefit," says co-author Dr Nathan Lo from the University of Sydney.
But Theo would also like to see the results imparting positivity towards the insects' negative image. "You say the word 'earthworm' and people...know they do good. But 150 years ago, people wanted to kill them. Darwin rehabilitated their image in one of his final studies," Theo says. "Maybe we can do a bit of a Charles Darwin for ants and termites."
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