Tanga Region, Tanzania, is an area of persistent rural poverty with a long history of drought, floods, food shortages, famine, and social and economic disruption. Though farmers have been cultivating the land there for hundreds of years, they have consistently been unable to supply adequate food for the region's inhabitants. In "Challenging Nature", Philip Porter examines eighteen farming communities to understand what the farmers there know about their environment and which historical and economic factors play into the lack of food security. Porter first began work on this project in 1972, asking 250 farmers in the region about life history, environmental and agricultural changes, types of crops grown and methods of planting, environmental assessments, agricultural practices, food and water supplies, training and education, and attitudes toward nature. Twenty years later, he returned and reinterviewed as many farmers as could be found from the first survey. The result contextualizes the environmental history of the region while informing current and future agricultural development.