THE grain industry can expect wheat protein levels to decline as a result of increasing atmospheric carbon dioxide levels.
That's one of the trends being picked up in a three-year research project on grain quality run by the Department of Primary Industries at Horsham.
The project is part of the broader Free Air Carbon Dioxide Enriched research program looking at how crops respond to elevated carbon dioxide levels as a result of global warming.
DPI research chemist Cassandra Walker said her research team was looking at how wheat quality changes with a 40 per cent increase in carbon dioxide levels.
The project tested eight common wheat varieties grown on irrigated and dryland plots at Horsham in four replicates.
She said the wheat harvested from each plot was tested for protein levels, test weight, screenings, milling attributes and noodle-making ability to see what effect climate change would have on grain quality.
She said the milling tests were the standard ones millers would carry out: dough mixing time, stability, strength and extensibility, plus water absorption of the flour. They were also making sheets of noodles to measure the colour and stability of noodle dough.
"We want to see the science behind what is going on with elevated carbon dioxide levels," she said.
The researchers bake small loaves to measure some characteristics of the flour.
Ms Walker said the key test was loaf volume, or how much bread could be made from the dough.
She said they were also monitoring the external appearance of each loaf, before slicing it to look at crumb structure and colour and texture of the bread.
Researchers have another harvest to go before results are collated.
She said one of the early trends was that grain protein contents decreased at the higher carbon dioxide treatments.
"But the grain tends to be larger," she said.
Ms Walker said if grain protein levels were declining as atmospheric carbon dioxide levels increased, farmers might have to apply more nitrogen to their crops.
Alternatively, wheat breeders might be able breed for higher protein levels.
"If different varieties respond differently, this would indicate a genetic effect," she said.