Sustainable intensification of millet–pig agriculture in Neolithic North China

The emergence of complex societies represents one of the major developments of human prehistory. Diverse agricultural strategies were implemented to produce the increased grain surplus necessary to allow the development of complex societies across the world. Little is known, however, about the millet–pig system that developed in Neolithic North China and ultimately underpinned the more complex societies, such as cities and states, in this region. Our data from studies of phytoliths and starches from pig dental residues and stable isotopes of millet grains excavated from the Dadiwan site demonstrate that an intensive crop–livestock system was in practice by at least 5,500 years ago. This novel system, characterized by the feeding of millet crop residues to pigs and the fertilization of millet fields with pig and/or human dung, enabled sustainable intensification in agriculture and fed the early complex societies in North China.