Along with rice and wheat, maize, also known as corn, provides at least 30 percent of the food calories for more than 4.5 billion people on the planet. Today, maize is the most important food crop in Sub-Saharan Africa (SSA) and Latin America. Compared to other plant commodities, the environmental impact from GHG emissions, land use, eutrophication potential, acidification potential, and freshwater withdrawal are most similar to palm oil and soy production. No apparent trends were found when comparing GHG emissions to the four other indicators, indicating overall independent relationships between all environmental indicators. There is a slight positive correlation between GHG emissions and land use, particularly for outlier countries in SSA, suggesting a possibility of a co-benefit relationship in certain cases. To explore potentially hidden relationships between indicators, we quantified the impact of specific production stages, which may be more consistent around the world and show trends that are isolated to on-farm or post-farm processes. We isolated the emissions created during each production stage for the five indicators. There are no apparent correlations between indicator values for production stages and GHG emissions. After observing that the range of impact intensities are largely driven by geography, we further explored these trends. Geographic analysis reveals abnormally high levels of land use and GHG emissions in SSA; this is most likely attributed to the “yield gap,” a phenomenon resulting from a lack of fertilizer input and optimized production systems which is especially prevalent in developing countries. As a staple food crop, demand for maize in developing countries is expected to increase 200% while yield will drop a predicted 10% by 2050. Based on our analysis, it is especially important that producers in developing nations find more land and energy-efficient methods of farming maize to match growth in demand, decrease environmental impact, and preserve livelihoods.
