Energy and Civilization: A History
Vaclav Smil
Solar radiation
espite many differences in agronomic practices and in cultivated crops, all traditional agricultures shared the same energetic foundation. They were powered by the photosynthetic conversion of solar radiation, producing food for people, feed for animals, recycled wastes for the replenishment of soil fertility, and fuels for smelting the metals needed to make simple farm tools. Consequently, traditional farming was,
