作物不仅能由根部吸收养料,而且也能通过叶部吸收养料。植物地上部分吸收养料的过程称为根外营养。尤其是在作物生长后期,根部吸收养料能力减弱,进行根外追肥能及时弥补根部吸收养料的不足。而且,根外 The crop can not only absorb nutrients from the roots, but also absorb nutrients through the leaves. The process of nutrient uptake by plant parts is called extragalactic nutrition. Especially in late crop growth, the ability to absorb nutrients at the root weakened, the root top dressing can make up for lack of nutrients to the roots. And, outside