How does rice handle the heat?
14 FEBRUARY 2012
The ability of a staple food crop, such as rice, to cope with climate change is under investigation in specially designed growth chambers at CSU in Wagga Wagga.
The ability of a staple food crop, such as rice, to cope with climate change is under investigation in specially designed growth chambers at Charles Sturt University (CSU) in Wagga Wagga.
The research, led by Associate Professor of Soil Management, Philip Eberbach from the School of Agricultural and Wine Sciences, is examining how tolerant rice is to higher temperatures and how the method of irrigation such as flood or drip irrigation may moderate elevated temperatures.
Associate Professor Eberbach said the project, funded by the EH Graham Centre for Agricultural Innovation is driven by concerns about global food security.
“Over half the global population depends on rice as a principal food source and there is concern about the ability of modern rice varieties to tolerate increased temperatures,” he said.
The research is being carried out in four cone-like growth chambers made of steel and clear plastic, which allow the researchers to increase the peak day time temperatures by up to 12 degrees.
“We are particularly interested in investigating the impact of the canopy of a rice crop in reducing high temperatures and whether this effect is due to shading or ponded water.
“We know from research over the past decade that ponded water can protect a flowering rice crop from cold night time temperatures by thermally buffering the air with in the rice crops,” Professor Eberbach said. “This project is looking at the impact of ponded water in hot conditions to reduce temperatures.”
The rice is being grown in large tubs; either being flooded like a traditional paddy production system, or grown in saturated soil using a tension watering system, where the water does not pool on the soil surface.
“What we’re trying to do in the saturated treatment is provide water to the roots of the plant so that transpiration is not affected while keeping the water away from the surface where you get enhanced rates of evaporation,” he said.
The scientists are measuring temperatures at different levels of the canopy of the plant and hope to find out if the pooled water acts like an evaporative cooler, protecting the crop.
Professor Eberbach said the rice will be harvested in March and April to assess the impact on grain production.