Seed World

New Study Shows Climate Variability Plays Large Role in Crop Yield

A new report from researchers at the University of Minnesota Institute on the Environment has found that climate variability historically accounts for one-third of yield variability for maize, rice, wheat and soybeans worldwide — the equivalent of 36 million metric tons of food each year. This provides valuable information for policymakers to help stabilize farmer income and food supply while boosting food security.
The researchers looked at newly available production statistics for maize, rice, wheat and soybeans from 13,500 political units around the world between 1979 and 2008, along with precipitation and temperature data. The team used these data to calculate year-to-year fluctuations and estimate how much yield variability could be attributed to climate variability.
According to the results, about 32 to 39 percent of year-to-year variability for the four crops could be explained by climate variability. This is substantial — the equivalent of 22 million metric tons of maize, 3 million metric tons of rice, 9 million metric tons of wheat and 2 million metric tons of soybeans per year.
The research team is looking at historical records to see whether the variability attributable to climate has changed over time — and if so, what aspects of climate are most pertinent.