Global food security must address the dual challenges of closing yield gaps (i.e., actual vs. potential yield) while improving environmental sustainability. Nutrient balance is essential for achieving global food security. Historical (in distinct “Eras” from late 1800s to 2012) and geographical (in United States vs. remainder of World) changes in maize (Zea mays L.) grain yields and plant nutrient content (N, P, and K) were characterized from studies (>150) with known plant densities.