Mechanical weeding

Agricultural researchers Leigh Vial and Matt Champness have teamed up, with support from The Crawford Fund, to trial mechanical weeding.

Dr Vial, who has a long history both growing rice in Australia and working in rice research in south-east Asia, said the labour-intensive methods of growing rice in the region were crippling.

"Labour productivity is probably the most important productivity that needs to be improved in the developing world," he said.

"There are already lots of examples of crops not being grown because it just takes too much work."

That's despite Laos's per capita rice consumption being among the highest in the world at 206 kilograms a year, according to the World Bank.

Dr Vial said a shift from transplanted to direct-seeded rice had saved a lot of labour — around 25 'person days' per hectare — but had created another challenge.

"When you change to direct-seeded rice, weeds generally rapidly worsen because the old transplanted rice system is actually quite good at managing weeds," he said.

A University of Queensland project funded by the Australian Centre for International Agricultural Research is currently focused on this issue.

"Herbicides can be used but it is tricky to use them in the wet season in the tropics, so Matt and I have embarked on a venture to improve mechanical weed control," Dr Vial said.

Bush mechanics in Laos
Their solution was to adapt a walk-behind cultivator — known as a rotovator — so that it cultivates between the rows of rice without damaging the plants.

Mr Champness said it had not all been smooth sailing.

"In a Laos context that's not so easy with very limited access to tools and machinery, but we've found a pretty handy mechanic and we've got him to adapt the rotovator," he said.

"We started off cultivating four rows at a time but that wasn't overly successful, so we've gone back to two rows for the minute and had some great success."

Mr Champness said mechanical weeding was crucial because of the sheer amount of time consumed in hand weeding.

"The weed populations get to a point where they just have to give up. You could spend all day getting up a single row," he said.

"So we're trying to bring back a solution that is viable from a time point of view."

A better life

Dr Vial said mechanisation held huge potential in improving the quality of life for farmers in developing countries.

"With modern techniques, the labour required to grow rice can be reduced by three-quarters or more," he said.

"It's often women and girls who get tasked with doing the hardest work in rice fields in south-east Asia, so if we can reduce the time taken to do it and improve the quality of how it's done, that'll have a massive effect for the female members of the population."

He encouraged Australian farmers to share their knowledge with the developing world.

"It's a wonderful opportunity. Australian farmers are very innovative and they have a very good skill set that can be of great value in the developing world," he said.