ABSTRACT
The doctrine of the decreasing importance of natural resources in economic growth is based on the observation, documented largely for the United States, that the shares of agriculture and of agricultural land in the national income have decreased in the course of economic growth. The natural resources used by agriculture are mainly land, water, and climate. With respect to natural resources originating and mainly used outside of agriculture, such as minerals and energy resources, there is evidence that their income shares have increased in the United States in some periods and decreased in others. In northern India, irrigation has been based for centuries on groundwater lifted from open wells by the Persian wheel, a simple but ingenious device to develop groundwater resources where they are available in large quantities not more than some 40 feet below the surface. This is the situation in large parts of the extensive Indo-Gangetic Plain.
