Description

Azolla is a genus of seven species of aquatic ferns in the family Salviniaceae. Azolla is extremely reduced in form and specialized, looking nothing like other typical ferns but more resembling duckweed or some mosses. It is typically considered an invasive plant in wetlands, freshwater lakes and ditches. It has the ability of substantially altering aquatic ecosystems and biodiversity.

The symbiotic relationship azolla forms with the cyanobacterium Anabaena azollae helps in fixing atmospheric nitrogen and this symbiotic microorganism transfers directly from one generation to the next. Azolla is fast finding increasing use in sustainable production of livestock feed. Azolla is rich in protein, essential amino acids, vitamins and minerals. Infact, the dry weight azolla has 25-35% protein content, 10-15% mineral content, and 7-10% combination of amino acids, bio-active substances and biopolymers. Low in carbohydrate and oil content, it comes rich in iron (1000–8600 ppm dry weight), copper (3–210 ppm dry weight), manganese (120–2700 ppm dry weight), vitamin A (300–600 ppm dry weight.), vitamin A (300–600 ppm dry weigh), chlorophyll and carotenes. Studies have shown that feeding azolla to dairy cattle, pigs, ducks, and chickens resulted in higher milk production, increased weight attainment in broiler chickens and more egg production of layers, when compared to those fed with conventional feed.

Apart from its use as feed for livestock, the nitrogen-fixing capability of azolla has led to its widespread use as a bio fertilizer, especially in parts of Southeast Asia. It has been used for over a thousand years in China to enhance In China, agricultural productivity. For instance, when rice paddies are flooded in the spring, it is usually cultivated alongside and they end up soon multiplying and taking over the water surface, thereby suppressing weeds. The rotting plant material also releases nitrogen into the water for the rice plants, providing up to 9 tons of protein per hectare annually.