fertilizer grade

例句：

1. 1.The fertilizer grade is crucial for the growth of crops.
   肥料等级对农作物的生长至关重要。
2. 2. Different types of fertilizers are available at various grades.
   不同种类的肥料在各个等级都有售。
3. 3.The farmer needs to choose the right fertilizer grade based on the soil conditions.
   农民需要根据土壤条件选择正确的肥料等级。