钾素是作物营养的三大要素之一。长期以来,由于受“土壤富钾”概念的影响,人们忽视按作物需要的氮、磷、钾比例实行平衡施肥,在施肥中只注重对氮磷化肥的使用。土壤钾素肥力的消耗得不到应有的补给,致使钾素含量逐年下降,作物施钾肥的肥效逐年增长。其增长的幅度因土壤肥力和作物种类不同而异。一般表现,高产田的施钾肥效大于中、低产田;玉米、棉花、大豆、芝麻施钾肥的增产机率大于小麦。由此可见,保持土壤钾素平衡,对实现农作物的持续增产,越来越重要。 Potassium is one of the three major elements of crop nutrition. For a long time, due to the influence of the concept of “potassium-rich soil”, people neglected the balanced fertilization according to the proportion of nitrogen, phosphorus and potassium required by the crop, and only paid attention to the use of nitrogen and phosphorus fertilizers in fertilization. The depletion of soil potassium fertility is not replenished, resulting in a decline in the amount of potassium and a year-on-year increase in the efficiency of crop potassium fertilization. The magnitude of its increase varies according to soil fertility and the type of crop. Generally, the potassium application efficiency of high-yielding fields was greater than that of middle-yielding and low-yielding fields. The rate of increase of yield of potassium by maize, cotton, soybean and sesame was higher than that of wheat. This shows that it is more and more important to maintain the balance of soil potassium and achieve a continuous increase of crops.