作物在任何时期都需要N、P、K三种营养元素。生产实践证明氮、磷、钾三种化肥合理配合施用,作物才能获得丰产。如果根据作物需要,将几种肥料混合在一起一次施用,这既能满足作物对不同养分的需求,又可节省劳力和机力,从而达到提高肥料效率,降低施肥成本的目的。尽管目前有了复合肥料,但还要以单元肥料调节其营养比例。当然,并不是在任何情况下任何肥料都能进行混合的。 Crops at any time need N, P, K three kinds of nutrients. Production practice proved that three kinds of nitrogen, phosphorus and potassium fertilizers with reasonable cooperation, crops can get high yield. According to the needs of crops, several kinds of fertilizers are mixed and applied together, which not only can meet the demand of crops for different nutrients, but also save manpower and labor, so as to achieve the purpose of improving fertilizer efficiency and reducing fertilizer cost. In spite of the current availability of compound fertilizers, their nutrient content is also adjusted with unit fertilizers. Of course, not any fertilizer can be mixed under any circumstances.