摘要
当前许多国家,由于高产作物品种的推广,氮肥施用水平的提高,加以对产品品质提出更高的要求,因而对钾肥的需要急剧增长,有的国家已感到缺钾的严重性,引起密切的关注。我国当前施肥上也存在氮、钾比例失调的现象。 钾肥资源不足是当前广泛应用钾肥的一个障碍。因此,近年来寻找具有强烈吸钾能力的绿肥作物,利用它把水土中的钾富集起来,是一个颇引起各方重视的解决钾肥的途径。我们在研究红萍固氮时发现,红萍具有较强的富钾能力,但至今未见这方面的研究报道。本研究的目的就是了解红萍富钾的内在可能性,以便为生产利用提供理论依据。
Azolla has a rather strong capacity for absorbing potassium from water.Results of the study showed that the K content of azolla was closely related to the K concentration in the suspending solution.When the latter was within the range of 0.1—500 ppm,the K content of azolla increased in logarithmic form.Under normal growing environment it was within the range of 0.2—0.3%.Azolla could rapidly recover and make use of the very low concentration of potassium.The peak of K absorption from solution occurred at the concentration of 0.85 ppm K_(2)O,which might be taken as the physiological critical point of K requirement of azolla,while the peak of K recovery for the rice from the suspending solution was at about 8 ppm.Since the K concentration in the irrigation water and rain was in the range of 1—5 ppm,it was even more difficult for rice to absorb and utilize.However,this low content of K could be rapidly recovered by azolla and enriched in the plant.And once incorporated into the soil,it will decompose and release the K.Therefore,azolla may be a potential potassium source for paddy rice when it is cultivated in the paddy field.
作者
刘中柱
魏文雄
郑国璋
翁伯琦
张逸清
Liu Chungchu;Wei Wenshung;Zhin Guochang;Weng Beiqi;Zhang Yiqing(Soil and Fertilizer Research Institute,Fujian Academy of Agricultural Sciences,Fujian Province,China)
出处
《中国农业科学》
1982年第4期82-87,共6页
Scientia Agricultura Sinica
