Yield Potential Key
to Food Security

Crop yields aren’t increasing fast enough to meet the world’s projected food needs, which are expected to double by 2050 as the population increases and becomes wealthier.

Knowing how much food each acre of land can produce is essential to increasing global food capacity without significantly expanding farmland, said Ken Cassman, UNL agronomy professor and director of the Nebraska Center for Energy Sciences Research.

Cassman and graduate student Justin van Wart are developing a transparent, science-based method to measure yield gap, the difference between average and potential crop yields. Identifying underperforming areas where yield could easily be increased could help prioritize research and inform agricultural policies.

"This work will be critically important to mobilize global resources for food security," Cassman said. It follows previous work on biofuels and food security with UNL biological systems engineer Adam Liska.

Using crop simulation modeling and geographic information systems technology, researchers are creating an atlas that shows yield potential for cropland in all countries that can provide data on crop, soil type and climate.

Atlas users will be able to compare an area’s potential yields with actual yields. Having detailed, field-level information will help researchers and policymakers strategize ways to help producers close the gap.

Cassman also envisions using the gap analysis tool to measure water productivity, the amount of water used to produce a crop. He and graduate student Patricio Grassini recently worked with Nebraska’s Tri-Basin Natural Resources District to estimate water productivity of corn.

Results showed the potential to reduce water used to irrigate corn by 33 percent while maintaining yields through adopting conservation tillage more widely, replacing surface irrigation with pivots and fine-tuning limited irrigation. These findings can help inform irrigation and water-use policies in the face of increasing competition for water resources.

"These are powerful tools to establish research priorities and inform agricultural policies at the global, national and regional levels,” Cassman said.