Satellite data play critical role in understanding yield gaps

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Estimates of average wheat yields in the Punjab region of India for 2000-2008, derived from Landsat satellite data. Red shows areas with highest yields, blue shows lowest yields, and white are non-wheat areas (e.g. towns). Black lines show location of major surface water canals, where yields tend to be higher.

According to a new study by FSE's David Lobell, satellite data can play a critical role in understanding yield gaps and meeting future crop demand. Lobell's review appeared in a special issue in Field Crops Research dedicated to crop yield gap analysis.

To date, satellite data have played a relatively small role in understanding the magnitude and causes of yield gaps in most regions. However, the few examples that exist indicate that remote sensing can help to overcome some of the inherent spatial and temporal scaling issues associated with field-based approaches.

"Yield gap profiles, based on multiple years of satellite data, provide a useful measure of how persistent yield-controlling factors are through time," writes Lobell in his review. "Although the cost or availability of satellite data with sufficient spatial resolution to discriminate agricultural fields was an obstacle in the past, this barrier is rapidly diminishing."

Improved algorithms to pre-process remote sensing data and estimate yields, and the increased availability of new, large geospatial datasets on soils, management, and weather should also benefit future efforts in this area.

"Improved knowledge of yield gaps will play a critical role in meeting future crop demands at affordable prices and with minimal environmental impacts," concludes Lobell. "The use of satellite data can accelerate the pace of discovery, and as such it represents an important area for future work."

All papers in this special issue can be accessed free of charge.