Agriculture provides food to humans and feed to livestock, livestock provide biomass energy for biogas, manure produced by cattle also provides fertilizer for agriculture, organic waste produced by citizens is used as biogas and fertilizer (see Figure 4.2.1). This web-like relationship is important to both energy and material flows. Here, four self-sufficiency rates are considered simultaneously: food, fertilizer, feed and energy for the city of Furano in northern Japan.