Rice is the crop grown in many Asian countries. In
it is major source of food for the majority of the population. It is a plant that requires plenty of water and heat. In Java, Bali, and other islands in Indonesia the rains are so plentiful that it is possible to grow three or four rice crops a year. Rice fields are surrounded by low walls to maintain the water at a time when fields are flooded. In mountain areas, the paddy fields form terraces where water flowing from the top successively fills each of them. Planting, harvesting and threshing rice is a slow process done by hand.