New Model Rivals USDA Yield Formula

Corn ready for harvest. ( Lindsey Benne )

Market-moving USDA reports are being rivaled by a new formula from the University of Illinois, and researchers say it is more accurate in making yield predictions.

“Our research demonstrates we can do better than USDA’s real-time estimation,” says Kaiyu Guan, a principal investigator on the Geophysical Research Letters study. He is also an assistant professor in the department of natural resources and environmental sciences (NRES) at the University of Illinois and a Blue Waters professor at the National Center for Supercomputing Applications (NCSA).

To formulate its estimations, the University of Illinois research team uses satellite data on seasonal climate predictions and in-season crop growth information from satellite imagery.

The team says its approach leads to earlier, more accurate end-of-season yield predictions. Between 2010 and 2016, for example, the World Agricultural Supply and Demand Estimates (WASDE) report for June was off by an average of 17.66 bu. per acre. The new system was only off by 12.75 bu. per acre. In August, during the same time, the WASDE report was off by 5.63 bu. per acre and the new system was only off by 4.36 bu. per acre.

“Compared with using historical climate information for the unknown future, which is what most previous research is based on, using seasonal climate prediction from NOAA’s [National Oceanic and Atmospheric Administration] National Centers for Environmental Prediction gave better forecasting performance, especially in reducing the uncertainties,” says Bin Peng, the lead author for the study and a post-doctoral research associate in NRES and NCSA.

It seems satellite imagery is the key to beating USDA estimates.

“If we only use seasonal climate prediction data—temperature, rainfall and vapor pressure deficit—our predictions were no better than USDA’s,” Guan says. “It was only when we added the satellite data that we started to see the improvement.”

More accurate yield predictions are important to farmers as they create their marketing plans. It could also benefit grain companies and local elevators, giving them a better idea of what kind of storage and sales opportunities they might have at the end of a season.