France successfully integrated the colonies into its economic system. By 1939, one third of its exports went to its colonies; Paris businessmen invested heavily in agriculture, mining, and shipping. In Indochina, new plantations were opened for rice and natural rubber. In Algeria, land held by rich settlers rose from 1,600,000 hectares in 1890 to 2,700,000 hectares in 1940; combined with similar operations in Morocco and Tunisia, the result was that North African agriculture became one of the most efficient in the world. Metropolitan France was a captive market, so large landowners could borrow large sums in Paris to modernize agricultural techniques with tractors and mechanized equipment. The result was a dramatic increase in the export of wheat, corn, peaches, and olive oil. French Algeria became the fourth most important wine producer in the world. Nickel mining in New Caledonia was also important.
