THE removal of a 45,000 litre gas cylinder from Agriculture Victoria’s Plant Breeding Centre at Horsham has marked the end of 11 years of field trails.
The trials were established to better understand the impacts of climate change and rising atmospheric carbon dioxide levels on dryland food production.
The Horsham-based Australian Grains Free Air CO2 Enrichment project – or AGFACE – was established to allow researchers to examine how crops would respond under elevated CO2.
It was the only facility of its kind in the world, having been built specifically to study the impact of elevated CO2 on field crops grown in semi-arid conditions.
To mimic future atmospheric carbon dioxide levels, which over the next 35 years are predicted to rise from 405ppm to 550ppm, a gas cylinder was installed at the plant breeding centre which fed into pipes arranged into 12 metre wide octagonal rings around the field trials.
Plants grown inside these rings were exposed to 550ppm levels of CO2 during daylight hours. Agriculture Victoria research scientist Glenn Fitzgerald led the AGFACE at Horsham.
The project was also supported by a large team of researchers specialising in the fields of cereal chemistry, agronomy, soil sciences, farming systems, pests and diseases, microbiology, agricultural engineering and crop modelling ensuring crop effects were looked at from all angles.
Dr Fitzgerald said a decade of experiments using the AGFACE infrastructure had produced a number of results and had significantly contributed to the collective understanding about food production under elevated CO2.
“A key finding was that crops grown under elevated CO2 grow bigger but they will need more nitrogen and phosphorus to support them, and grain quality will decrease,” he said.
The research also showed that the impact elevated carbon dioxide had on crops varied according to cultivar, which suggests that adaptation to a changing climate is possible with targeted plant breeding.
Dr Fitzgerald said there were a number of important other findings that resulted from the extensive AGFACE research.
“Increasing temperatures and reduced rainfall in the future may tend to lower yields, counteracting the benefits of CO2,” he said.
“We also found that greater legume growth under elevated CO2 could benefit future rotation systems by supplying more nitrogen to soils, but more phosphorus fertiliser will be required to maintain growth on deficient soils.”
Computer modelling carried out as part of the project showed that the impacts of elevated CO2 will vary across the landscape depending on rainfall, temperatures and soils.
AGFACE was a joint project of Agriculture Victoria and the University of Melbourne, with funding support from the Grains Research and Development Corporation, the federal Department of Agriculture and Water Resources and the Australian Research Council.