Rice is grown in more than a hundred countries, with a total harvested area of approximately 158 million hectares, producing more than 700 million tons annually (470 million tons of milled rice). Nearly 640 million tons of rice are grown in Asia, representing 90% of global production. Sub-Saharan Africa produces about 19 million tons and Latin America some 25 million tons. In Asia and sub-Saharan Africa, almost all rice is grown on small farms of 0.5−3 ha. Yields range from less than 1 t/ha under very poor rain fed conditions to more than 10 t/ha in intensive temperate irrigated systems. Small, and in many areas shrinking, farm sizes account for the low incomes of rice farm families. Rice grows in a wide range of environments and is productive in many situations where other crops would fail. The highest rice yields have traditionally been obtained from plantings in high-latitude areas that have long day length and where intensive farming techniques are practiced, or in low-latitude desert areas that have very high solar energy. South western Australia, Hokkaido in Japan, Spain, Italy, northern California, and the Nile Delta provide the best examples. More than anywhere else in the world, rice dominates overall crop production (measured by the share of crop area harvested of rice) and overall food consumption (measured by the share of rice in total caloric intake) in rice-producing Asia.