Rice is the largest global staple crop, consumed by more than half the world’s population – but new experiments from Stanford University suggest that with climate change, production in major rice-growing regions with endemic soil arsenic will undergo a dramatic decline and jeopardize critical food supplies.
These experiments exploring rice production in future climate conditions show rice yields could drop about 40 percent by 2100 – with potentially devastating consequences in parts of the world that rely on the crop as a basic food source. What’s more, changes to soil processes due to increased temperatures will cause rice to contain twice as much toxic arsenic than the rice consumed today. The research was published Nov. 1 in Nature Communications.
“By the time we get to 2100, we’re estimated to have approximately 10 billion people, so that would mean we have 5 billion people dependent on rice, and 2 billion who would not have access to the calories they would normally need,” said co-author Scott Fendorf, the Terry Huffington Professor in Earth system science at Stanford University’s School of Earth, Energy & Environmental Sciences (Stanford Earth). “We have to be aware of these challenges that are coming so we can be ready to adapt.”
The researchers specifically looked at rice because it is grown in flooded paddies that help loosen the arsenic from the soil and make it especially sensitive to arsenic uptake. While many food crops today contain small amounts of arsenic, some growing regions are more susceptible than others. Future changes in soil due to higher temperatures combined with flooded conditions cause arsenic to be taken up by rice plants at higher levels – and using irrigation water with naturally occurring high arsenic exacerbates the problem. While these factors will not affect all global commodities in the same way, they do extend to other flood-grown crops, like taro and lotus.
Read more at Stanford's School of Earth, Energy & Environmental Sciences
Image: E. Marie Muehe removes rice grains from stalks so they can be weighed for yield and analyzed for arsenic content and other nutritional information. (Credit: Kurt Hickman/Stanford News Service)