Wendy Zukerman, Asia-Pacific reporter
Never mind fertilisers and pesticides: for a natural solution to boosting crop yields in arid regions, turn to termite power.
Theodore Evans at CSIRO Ecosystem Sciences in Canberra, Australia, has shown that the insects can increase the yield of wheat crops by 36 per cent.
Earthworms improve soil health in cool and wet climates, but they can't survive in the arid soils of southern Australia, Africa and South America. But termites and other burrowing insects can. Like earthworms, ants and termites allow more water to get into the soil by digging tunnels, and their nitrogen-packed faeces are a natural fertiliser.
To make his case, Evans and his colleagues doused five farm plots in Australia's south-eastern wheat belt with insecticide in May 2006. By November 2008, yields on untreated plots were on average 36 per cent higher than on treated plots.
A careful count revealed that getting rid of the termites had halved the number of tunnels in the soil. In 2006, they counted around 0.65 tunnels per 100 square centimetres on all plots, but by 2008 that had dropped to 0.35 per 100 square centimetres on treated plots. Evans says that over the two years, the tunnels that weren't regularly maintenained by termites collapsed.
The team also found that removing the insects reduced total mineral nitrogen - a fertiliser - by around 70 per cent.
The conclusion? For Evans, it's straightforward: help termites and ants move into your farmland by - among others measures - cutting the frequency and depth of ploughing.
Not so fast, said Martin Williams at the University of Adelaide, Southern Australia, when we contacted him. He pointed out that many termite species are herbivores and would eat the cereals growing above them - a something of a setback if you're the farmer. In Evans's study, the termites ate the wheat stubble, rather than the wheat.
And then of course there's the small matter of the termite mounds, which take up precious room. So, a nice idea but perhaps one that needs a bit more thought.