For example, using animal waste may be best for farms that have the animals to supply it.But on farms that cannot get fertilizer, the best solution may be the method of rotating sorghum with cowpea .

• 比如，使用动物粪便对饲养动物的农民来说就是最好的方法，但对那些没有肥料的农民来说，最好的办法就是轮种高梁和豇豆。