钾是肥料三要素之一,而且其需要量(按K_2O算)比氮、磷(按P_2O_5算)还多。随着单产的增加和复种指数的提高,作物对钾的需求量已愈来愈大,仅靠土壤中的钾和少量的草木灰已不能满足高产的需要了。目前我国生产的钾肥较少,加之不少地方较普遍地存在着重氮肥、轻磷肥、忽视钾肥的倾向, Potassium is one of the three elements of fertilizer, and its requirements (calculated by K_2O) than nitrogen and phosphorus (calculated by P_2O_5) more. With the increase of yield and the improvement of multiple cropping index, the demand of crop for potassium has been getting bigger and bigger. Only the soil potassium and a small amount of ash can not meet the demand of high yield. At present, China produces less potassium, combined with the more common in many places there is a heavy nitrogen fertilizer, phosphorus fertilizer, potassium tend to ignore,