The aquatic fern Azolla spp. is of value as a bio-fertilizer for wetland paddy. It is popular and cultivated widely in other countries like China, Vietnam, and the Philippines, but has yet to be taken up in Korea, in a big way. It fixes nitrogen as high as 3-5kg N per day, because it contains nitrogen fixing blue-green algae, Anabaena azollae. Azolla's ability to create a light-proof mat that suppresses other weeds has been used for centuries in rice production. Azolla spp. has also the capacity to take up the heavy metals such as Mercury and Chromium (75~100%) and may be used as a bioaccumulator in the phytoremediation. Azolla meal also can be used as an unconventional feed resource has a potential as a feedstuff for livestock.

• Ki-Woong Nam
• Deok-Hoon Yoon