The Indus Civilization (Cambridge History of India, Supplementary Volume) c16.1

c16.1

Whilst a city of the size of Mohenjo-daro or Harappā implies a substantial middle class financed from trade and industry, the basic economy was necessarily agricultural, and there is evidence for a considerable variety in the crops available to the Harappans. On the other hand, as already noted, the building up of the flood-plain by alluvial deposits during the past three or four thousand years has obscured such evidence of field-systems and irrigation as might otherwise have survived. Our knowledge is derived solely from grains and fruits which happen to have endured in the occupation-material.