|Coming soon to a farm near you?|
Ants and termites can massively increase crop yields on arid farms, according to an Australian research team.
Dry soils contain few if any earthworms. Instead, insects break up soil and move nutrients, but little is known of their effects, says Evans.
Previous studies have shown that ants and termites influence soil processes such as nutrient cycling and water infiltration, but there has not been an experimental demonstration that they increase crop yield, note Evans and his colleagues in a paper in Nature Communications.
To fill this gap, the team used insecticide to eliminate ants and termites from half of the plots on their experimental farm in Western Australia. Areas where the insects remained produced 36% more wheat on average. The insects appear to have increased water infiltration into the soil with their burrowing and to have improved soil nitrogen levels.
Now the question is whether the benefits of insects can be captured and put to use. The animals are happiest on farms run on ‘conservation agriculture’ lines, points out Evans. This includes minimal ploughing and machinery traffic, leaving stubble after harvest and – obviously – lower use of pesticides.
Local insects should quickly colonize fields managed this way. If there are not local populations the issue becomes trickier. It is also not yet clear whether yields will increase in other environments.
“I suspect the greatest yield increases will be in driest and most marginal cropping lands, because water infiltration is the most important limitation to plant growth in such habitats,” Evans told Nature.
“I wonder about sub-Saharan Africa, the dry veld of Southern Africa, Mexico, and India in particular. I am planning to ask that question for other crop species in the next phase of my research.”
Image: Termite mound in west Australia. Photo by robertpaulyoung via Flickr under creative commons.