change the order of crops

• 变化轮作次序

change the order of crops的用法和样例：

例句

1. Most of it has been retained in alternate husbandry.
   其中大部分成为轮作草地。
2. Crop rotation makes a balanced demand on the fertility of the soil.
   轮作可以平衡对土壤的肥力要求。