This book investigates the effect of the Green Revolution (GR) on long-term changes in the fertility status of paddy soils in tropical Asia. While information on long-term changes in soil fertility status are rather limited due to difficulties in obtaining past data or samples for comparison, this investigation on temporal changes in soil fertility is possible by comparing fertility status in the 2010s, which the authors examined recently, with those from the 1960s, when GR was initiated, which was reported by Kawaguchi & Kyuma (1977). More than 220 paddy soils collected from Thailand, the Philippines, Malaysia, Bangladesh, and Indonesia were analyzed for their physicochemical properties as well as total and available fractions of plant macro- and micro- essential elements, and their temporal changes were examined in addition to their spatial variation in each country. The most significant change was a drastic increase of available phosphorus in soils, possibly due to fertilization after the GR. Changes in organic matter, pH, and other nutrients were relatively small. A considerable decrease in the content of some micronutrients was also observed. Long-term studies on soil fertility status in the past and present will be useful to establish soil/fertilizer management for sustainable rice production in the future. This book is an essential reading for soil scientists, agricultural scientists, environmental scientists, as well as policymakers and nongovernmental officers such as FAO.