Field study shows why food quality will suffer with rising carbon dioxide
▻http://phys.org/news/2014-04-field-food-quality-carbon-dioxide.html
For the first time, a field test has demonstrated that elevated levels of carbon dioxide inhibit plants’ assimilation of nitrate into proteins, indicating that the nutritional quality of food crops is at risk as climate change intensifies.
Findings from this wheat field-test study, led by a UC Davis plant scientist, will be reported online April 6 in the journal Nature Climate Change.
“Food quality is declining under the rising levels of atmospheric carbon dioxide that we are experiencing,” said lead author Arnold Bloom, a professor in the Department of Plant Sciences.
“Several explanations for this decline have been put forward, but this is the first study to demonstrate that elevated carbon dioxide inhibits the conversion of nitrate into protein in a field-grown crop,” he said.
The assimilation, or processing, of nitrogen plays a key role in the plant’s growth and productivity. In food crops, it is especially important because plants use nitrogen to produce the proteins that are vital for human nutrition. Wheat, in particular, provides nearly one-fourth of all protein in the global human diet.
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While heavy nitrogen fertilization could partially compensate for this decline in food quality, it would also have negative consequences including higher costs, more nitrate leaching into groundwater and increased emissions of the greenhouse gas nitrous oxide, he said.