The global demand for food is rapidly increasing, and agriculture must become more productive to meet these needs. Measuring crop production performance from local to national scales is difficult because of the large variance in regional biophysical factors (like climate and soil - which have a significant influence on crop yields), organic and inorganic fertilizer inputs, and resilience to a variable climate. The following performance metrics allow for unbiased comparisons across the variety of variables:
- (i) the yield gap - the difference between current farm yield and potential yield when crops are grown with optimal nutrient supply and protection against pests; and
- (ii) yield stability - quantified by the degree of year-to-year yield variation due to rainfall and temperature variation.
These metrics are evaluated in the Global Yield Gap Atlas (GYGA), which covers local to national and continental scales within an agronomically relevant spatial framework. The GYGA is an international project initiated by researchers from the University of Nebraska-Lincoln and Wageningen University. The Atlas has been developed for 55 countries across five continents and includes major cereal crops. The crop list has recently been extended to include soybean, sugarcane, and potatoes, and additional information on water productivity and nutrient requirements will be future additions.