We study the interactions between food production, food security, and the environment using a range of modern tools. The work is motivated by questions such as: What investments are most effective at raising global crop yields, in order to increase food production without expansion of agricultural lands? Will yield gains be able to keep pace with global demand for crop products, given current levels of investment? And what direct or indirect effects will efforts to raise crop productivity have on other components of the Earth System, such as climate? Answering these requires an understanding of the complex factors that limit crop yields throughout the world, and the links between agriculture and the broader Earth System. Current work focuses on three main areas of research.