Dried paddy being wrapped into bunches. - - Rice Growing in Java.. Central Java is one of the most heavily populated rural areas in the world. In some parts, the demographic density reaches 1,500 inhabitants per square km. Javanese farmers are extremely diligent; they produce three rice crops per year, stock the flooded rice fields with fish and, in addition, raise ducks on the surface of the water. Undoubtedly, there is no other area in the world where as much starch and protein is being produced per area unit.