Land Suitability for Rainfed Agriculture:
Source: "Global Agro-ecological Assessment for Agriculture in the 21st Century,
Plate 46: Suitability for rain-fed crops (maximizing technology mix),"
[PDF] IIASA/FAO

Wheat Potential Yield and Actual Yield:
Source: "World Agriculture: Towards 2015/2030," FAO

Rice Potential Yield:
Source: "Reflections on Yield Gaps in Rice Production: How to Narrow the Gaps,"
Mahmud Duwayri, Dat Van Tran, and Van Nguu Nguyen, FAO

Rice Actual Yield:
Source: 2005 data, FAO

Corn Potential Yield and Actual Yield:
Source: "World Development Report 2008: Agriculture for Development," [PDF] World Bank

U.S. Corn Potential Yield:
Source: Kenneth Cassman

U.S. Corn Actual Yield:
Source: 2005 data, FAO

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.