Climate change is all over the news these days, and when a report in the journal Science indicates potential impacts on the future of food production in the US, people sit up and take notice.
David Lobell, associate professor of environmental Earth system science and associate director of the Center on Food Security and the Environment, led a team that analyzed data on corn and soybean production along with daily weather data in actual fields in the Midwestern United States.
The large dataset of crop and weather information compiled for these studies is now available for download from the Stanford Digital Repository. It's great that the accumulated effort this data set represents is now preserved and available for other scientists to use!
The goal was to look at crop yields over time for different kinds of stresses and to assess drought sensitivity. Studies to address these types of questions are often undertaken in experimental fields, but that methodology does not always yield results that are directly translatable to "real" farming.
So, what did Lobell's team find out? Use of no- or low-till systems and advances in genetics have allowed farmers to sow fields more densely (more plants per acre), resulting in improved crop yields. However, the study finds that drought sensitivity in these fields has increased over the last 18 years. This may be because increased sowing density imposes higher stress on the plants in times of drought.
At the current rate of sensitivity, climate change models indicate that corn yields could decline as much as 15% over the next 50 years. However, if sensitivity of these plants continues to increase as well, losses could amount to as much as 30%.