Using field chambers with elevated carbon dioxide and warmer temperatures, lead researcher Dr Katie Broughton found increased early-stage vegetative growth of between 34 and 68 percent. The multi-institutional team also saw increased leaf level water use efficiency.
The study is published in the journal Crop Science.
Dr Broughton’s PhD research at the University of Sydney was a collaboration between CSIRO Agriculture and Food, the University of Sydney, Western Sydney University and the United States Department of Agriculture.
Dr Broughton is now working with the CSIRO cotton breeding team based in Narrabri.
“I am pleased that this collaboration has led to a successful outcome with several years of investment in the cotton climate change facility at Narrabri by the Cotton Research and Development Corporation,” said University of Sydney agronomist, Associate Professor Daniel Tan from the Sydney Institute of Agriculture and School of Life and Environmental Sciences.
The research team successfully used novel Canopy EvapoTranspiration and Assimilation field chambers for the first time in Australian cotton to elevate carbon dioxide to 650 parts per million and raise air temperatures by 2 to 4 degrees in the field over two consecutive cotton seasons. Current atmospheric carbon dioxide is at about 410 parts per million.
Despite producing larger plants with higher rates of photosynthesis, elevated carbon dioxide also improved leaf-level water-use efficiency (measuring carbon assimilation and transpiration), which resulted in no increase in soil water use, compared with ambient carbon dioxide.
Declaration: The authors acknowledge the continued support and funding by the Cotton Research and Development Corporation and the Australian Postgraduate Award (APA) scholarship for Dr Katie Broughton’s PhD.