AsianScientist (Mar. 29, 2011) – Ants and termites have a significant positive impact on crop yields in dryland agriculture, according to a paper published today in the journal Nature Communications by scientists at CSIRO and the University of Sydney.
These insects play a role in dryland agriculture – similar to that by earthworms in cooler and wetter areas.
“We already knew that the activities of ants and termites affect soil structure, aeration, water infiltration and nutrient cycling in natural ecosystems but we wondered whether they also perform these services in agricultural landscapes,” said CSIRO’s Dr. Theo Evans.
This is the first study to show a crop yield increase due to soil fauna in the field.
Their studies of soil containing ants and termites gave on average a 36 percent higher wheat crop yield under low tillage but otherwise conventional agricultural management.
Two main reasons may explain the increases in yield. First, tunnels dug by ants and termites let more rain penetrate deeper into the soil where plants can access it, which also reduces runoff and evaporation. Second, the insects increase soil nitrogen as the termites have nitrogen fixing gut bacteria (functionally similar to those in the root nodules of legumes).
The benefits of ants and termites may likely to be greatest in hot and dry climates where water is a limiting resource for plant growth, due to their positive effect on water infiltration into the soil.
The team’s next big challenge will be to identify soils that can gain the most benefit, the most beneficial species, and how to promote their return to farms where they have been lost due to decades of intensive tillage and pesticide use.
The article can be found at: Evans T. et al. (2011) Ants and termites increase crop yield in a dry climate.
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Source: CSIRO, Nature Publishing Group.
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