Future drought will offset benefits of higher CO2 on soybean yields
- September 5, 2016
- University of Illinois at Urbana-Champaign
- An eight-year study of soybeans grown outdoors in a carbon dioxide-rich atmosphere like that expected by 2050 has yielded a new and worrisome finding: Higher atmospheric CO2 concentrations will boost plant growth under ideal growing conditions, but drought — expected to worsen as the climate warms and rainfall patterns change — will outweigh those benefits and cause yield losses much sooner than anticipated.
The new discovery, reported in the journal Nature Plants, contradicts a widely accepted hypothesis about how climate change will affect food production, said University of Illinois plant biology professor Andrew Leakey, who led the new research.
“If you read the most recent Intergovernmental Panel on Climate Change reports and if you read the scientific literature on the subject for the last 30 years, the concluding statement is nearly always that elevated carbon dioxide will ameliorate drought stress in crops,” Leakey said.
Numerous laboratory and field studies have supported this assessment: In many scenarios, elevated carbon dioxide acts as a fertilizer, boosting plant growth. Plants exposed to high CO2 also reduce the size of the pores in their leaves, lessening the exchange of gases with the atmosphere. This helps plants use less water from the soil.
Such findings strongly suggested that elevated CO2 would help plants better withstand drought, Leakey said.
Read the full article: Science Daily