水稻一生对钾的需求超过对氮的吸收。据有关资料报导,水稻对氮磷钾的需要比例为10:5:18。由于土壤母质大多含有相当数量的钾,钾在土壤中的自然贮量远较氮磷丰富,因此作物缺钾的矛盾一般不那么明显。但是,近一、二十年来,随着氮磷化肥用量的增加,复种指数的提高,高产品种的推广,单位面积产量的上升,作物从土壤中吸收越来越多的钾,致使土壤钾的贮量日 The demand for potassium in rice throughout life exceeds the absorption of nitrogen. According to the information reported, the ratio of rice to NPK is 10: 5: 18. Because most of the soil parent material contains a considerable amount of potassium, the natural reserves of potassium in the soil are much more abundant than nitrogen and phosphorus, so the contradiction between crop potassium deficiency is generally not so obvious. However, over the past one or two decades, with the increase of the amount of nitrogen and phosphorus fertilizer, the improvement of multiple cropping index, the promotion of high-yielding varieties and the increase of yield per unit area, crops absorb more and more potassium from the soil, Storage days