... not yet – and at the end of the seventeenth-century the Dutch were fi rmly in control, having captured much of the supply side of the trade by taking over Java, Malacca, Ceylon, and the Celebes, ... When they were rotated with rice crops, the technique facilitated utilization of the sandy soils along the lower Yangtze and the lower Yellow River, as well The Columbian Exchange and the Old ... those of other rivers and streams. And, fi nally, sweet potatoes – among the most important of the American foods in China – soared in popular-ity, so much so that by the 1920s, the poor in the...