輪作制情况引黄灌区的輪作制主要有两种:一种是位处灌区下游,排灌条件差,土质粘重,不能种稻(或很少种稻)的銀川以北地区的小麦与糜子輪作。卽种二、三年小麦后种一茬糜子,然后再种小麦;在地力瘠薄时,糜子后种一茬胡麻或“合禾”,然后再种小麦。这类地区,小麦中間作大豆或小麦收后复种糜子的很少,麦收后大多翻晒歇茬。另一种是位处灌区中上游,灌排条件較好,有种稻习慣的銀川以南及中卫、中宁地区的稻旱輪作。卽水稻与小麦等旱作物輪作,銀川以南 Crop rotation system There are mainly two rotation cropping systems in the Yellow River irrigated area: one is the rotation of wheat and millet in the area north of Yinchuan in the lower reaches of the irrigation area with poor drainage and irrigation conditions, poor soil quality, and inability to grow rice (or few kinds of rice) . Breeding species two or three years after planting a crop of barley, and then wheat; barren in the ground when the millet seeds planted flax or “Wo” and then wheat. Such areas, the middle of wheat or wheat after the recovery of mixed broomcorn millet rarely after the wheat harvest drying stubble. The other is located in the upper reaches of the irrigation area, irrigation and drainage conditions are better, there is a habit of rice in the south of Yinchuan and Zhongwei, Zhongning region rice dry rotation.旱 Dry crops such as rice and wheat crop rotation, south of Yinchuan