“With minimum tillage, the minimum disturbance means conserving that moisture, and the crop residue on the surface keeps it from drying out.”— Prof Bell. Image: UN PhotosA MURDOCH University professor is leading an international project to develop a system of conservation agriculture for small farmers in north-western Bangladesh, in order to alleviate potential food shortages in the changing climate.
Professor Richard Bell, from the School of Environmental Science, has led the Australian International Agricultural Research (ACIAR) project for six years.
The project has been introducing sustainable cropping practices based on conservation agriculture research, as well as transposing advanced Australian farming practices to the region.
Two of the main components involve developing systems to maintain crop residue and introducing minimum tillage techniques.
Tillage had been used for hundreds of years to cultivate the soil before sowing, to soften the seedbed and make it easier for the seeds to germinate. It can also help to manage weeds.
However, it has been since understood that this has a variety of negative effects on the soil such as; erosion; breakdown of structure; reduction of organic matter; and a loss of ability to store nutrients and water.
Minimum tillage is now commonly recognised to be the most sustainable farming practice.
However, Prof Bell says it is necessary to change farmers’ traditions in Bangladesh to sustain agriculture as the climate varies – as minimum tillage promotes soil resiliency.
“It seems what they are experiencing [in north-western Bangladesh] is perhaps more variability; so when it’s, wet its ‘more’ wet and when it’s dry, it’s perhaps more extreme,” he says.
“With minimum tillage, the minimum disturbance means conserving that moisture, and the crop residue on the surface keeps it from drying out.”
Prof Bell also says by transposing some of the successfully applied methods learnt from WA’s variable climate, small farmers can have the best chance for the future.
“A good example is South West WA, where our grain farmers have experienced drops in rainfall in the order of 10-15% in the last 30 years—but there average yields have gone up in that period, because they’ve been adapting, and modifying their practices incrementally,” he says.
In Bangladesh, Prof Bells says the project now aims to introduce methods to establish rice that does not require traditional puddling, because water tables in the region are dropping rapidly, partly due to over-pumping of ground water.
However, Prof Bell says it is not as simple as changing only the tilling practices.
“When you change the till, you have to change the agronomy,” he says.
This may include adjusting the fertiliser program so crops still get adequate nutrients at sowing, and using varieties that have early root vigour to push through firmer, untilled soil.
This project is a collaboration with the International Maize and Wheat Improvement Centre and iDE.
