根据川西北旱区气候资源，现有耕作制度两季有余，三季不足。以小麦──水稻为主的两熟制，有水源保证的常年亩（１亩＝１／１５公顷，下同）产８００公斤左右（小麦亩产３００公斤、水稻亩产５００公斤），无水原保证的望天田、高　田等亩产仅７００公斤左右（小麦亩产３００ According to the climate resources in the arid region of northwest Sichuan, the current farming system is more than two quarters, with less than three quarters. The perennial mu (1 mu = 1/15 ha, the same below) wheat-rice-based two-cropping system with guaranteed water sources produces about 800 kg (300 kg of wheat per mu and 500 kg of rice per mu) Promised Tiantian, Takada and other acres only about 700 kilograms (300 acres of wheat per mu