Nature has endowed Bali with ideal conditions for the development of agriculture. The divine volcanoes, still frequently active, provide the soils with great fertility. Copius rainfall and numerous mountain springs supply many areas of the island with ample water year-round. And a long dry season, brought on by the southeasterly monsoon, brings plentiful sunshine for many months of the year. Bali is, as a results, one of the most productive traditional agricultural areas on earth, which has in turn made possible the development of a highly intricate civilization on the island since very early times. 

Rice as the staff of life 

Wet-rice cultivation is the key to this agricultural bounty. The greatest concentration of irrigated rice fields is found in southern-central Bali, where water is readily available from spring-fed streams. Here, and in other well-watered areas where wet-rice culture predominates, rice is planted in rotation with so-called palawija cash crops such as soybeans, peanuts, onions, chili peppers and other vegetables. In the drier regions corn, taro, tapioca and beets are cultivated. 

Rice is, and has always been, the staff of life for Balinese. As in other southeast Asian languages, rice is synonymous here with food and eating. Personified as the "divine nutrition" in the form by the form of the goddess Bhatari Sri, rice is seen by the Balinese to be part of an all-compassing life force of which humans partake. 

Rice is also an important social force. The phases of rice cultivation determine the seasonal rhythm of work as well as the division of labor between men and women within the community. Balinese respect for their native rice varieties in expressed in countless myths and in colorful rituals in which the life cycle of the female rice divinity ore portrayed-from the planting of the seed to the the harvesting of grain. Rice thus represent "culture" to the Balinese in the dual sense of culture and cultus-cultivation and worship. 
 
Irrigation cooperatives (Subak) 

Historical evidence indicates that since the 11th century, all peasants whose fields were fed by the same water course have belonged to a single subak or irrigation cooperative. 
This is a traditional institution which regulates the construction and maintenance of waterworks, and distribution of life-giving water that they supply. Such regulation is essential to efficient wet-rice cultivation on Bali, where water travels through very deep ravines and across countless terraces in its journey from mountains to the sea. 

Source : BALI, Periplus Travel Guide Edition