论文部分内容阅读
钾是植物的三个主要营养元素之一。在自然界中,钾的分布较磷为多,比方岩石中,如花岗岩和片麻岩中钾的含量可达4～6％,玄武岩中约为1～5％,平均地壳中的含钾量约为2.6％,而磷仅为0.12％。 在岩石风化和硅酸盐分解时,部分钾以碳酸盐和硅酸盐形态被淋洗而进入海中。根据Clarke的资料(7),欧洲地壳的表层,每年洗入河水中的钾(K_2O)约为每平方公里1.2吨,即每公顷约12公斤;而个别地方,其洗失量可大到5～6倍。部分钾则以不同形态残留于土壤中,其中以难溶状态为主。
Potassium is one of the plant’s three main nutrients. In nature, the distribution of potassium is more than that of phosphorus. For example, the content of potassium in granite and gneiss ranges from 4 to 6%, and the basalts account for about 1 to 5%. The average potassium content in the crust is about 2.6%, while phosphorus was only 0.12%. During rock weathering and silicate decomposition, some of the potassium is eluted into the sea as carbonate and silicate. According to Clarke’s data (7), the surface layer of the European crust has an annual K2O of about 1.2 tons per square kilometer, or about 12 kilograms per hectare. In some places, the amount of loss can be as much as 5 ~ 6 times. Some of the potassium remains in different forms of soil, of which the state of insoluble.