Posted by Rita Mu
Ants and termites have a significant positive impact on crop yields in dryland agriculture, according to new research by the CSIRO and University of Sydney.
The research, published in the journal Nature Communications, revealed that ants and termites in soil boosted wheat crop yield by an average 36 per cent under low tillage but otherwise conventional agricultural management.
CSIRO’s Dr Theo Evans said the research was the first of its kind to show a crop yield increase due to soil fauna in the field.
"Ants and termites perform the same ecosystem service functions in dryland agriculture that earthworms perform in cooler and wetter areas, but the potential for ants and termites to provide these benefits has received little attention until now," Dr Evans said.
"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.”
Dr Evans said there were two likely reasons for the increase in yields: “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,” she said. “Second, the insects improve soil nitrogen, probably because termites have nitrogen fixing gut bacteria, which could help reduce fertilizer costs.
"We suspected that ants and termites may be a useful management tool for farmers, based on previous knowledge gained from studies in natural ecosystems, but we were very surprised by the large size of their influence in agricultural systems.”
According to Dr Evans, the benefits of ants and termites are 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.
Co-author of the paper, Dr Nathan Lo, from the University of Sydney said the results of the study were promising as they could lead to less environmentally harmful petroleum-based products such as herbicides, pesticides and fertilisers being used in farming.
"The number of arid farming areas, particularly in a country such as Australia, promises to increase as a result of climate change,” he said. “To find out that ants and termites can increase crop yields in this way is a really exciting result."
Image: CSIRO scientists counting termite tunnels under one of the plots of the study, Source: Theo Evans, CSIRO Entomology, Canberra