Azolla and Its Uses
Introduction to Azolla
Azolla is a floating aquatic pteridophyte (a fern) with symbiotically associated nitrogen fixing cyanobacteria (Anabaenae azollae). Azolla is sometimes called ‘small duckweed’, but this is a misleading name. Azolla is a pteridophyte, whereas duckweed (also known as ‘water lens’ or ‘bayroot’) is an aquatic angiosperm (flowering plant). The six species of Azolla are: A. carolina, A. filiculoides, A. mexicana, A.microphyla, A. nilotica and A. pinnata. Out of these Azolla pinnata is very common and good yielder in tropical climates.
Nutrition Profile Of Azolla
|4.||Nitrogen||5%(dry weight basis)|
|6.||Dry Matter||80 MT/ Ha|
Azolla Cultivation Method
- Make an artificial pond for growing Azolla.
- For Azolla cultivation pond, select partially shaded area because Azolla needs 30% sunlight too much sunlight will destroy the plant. The area under the tree is preferable.
- Decide to grow an Azolla for the large scale you can make small concrete tanks otherwise you can make the pond any size you want.
- Dig out the soil for pond and level the soil after that spread the plastic sheet around the ground to prevent water loss. Make sure the pond is at least 20 cm Deep.
- Add some soil uniformly on the plastic sheet in the pond. For 2m X 2m size pond add 10-15 kg soil.
- Azolla needs Phosphorus to grow well you can use Super Phosphate along with cow dung slurry. Cow dung increases the available nutrients. Use, cow dung 4-5 days old.
- Next, fill the pond with water to a level of about 10 cm this will allow the short route of the Azolla Plant to float freely then leave the pond for 2 to 3 days so the ingredients can settle.
- After 2-3 days add Azolla culture in the pond by gently rubbing Azolla in hands. It helps break Azolla into smaller pieces for faster multiplication.
- After two-week start harvesting. Form pond of 2m X 2m size, you can harvest 1kg Azolla each day.
Common Azolla Cultivation Practices
- Rice – Azolla
- Fish- Azolla
- Rice- Fish- Azolla
- Pig- Duck- fish- Azolla
Uses of Azolla
Azolla has tremendous benefits and can substantially increase the farmer’s income by decreasing expenditure on fertilizers and animal feed. We are listing here some of the major uses:
Azolla can be used to increase rice yield by several folds at comparatively low cost and less labour. They are grown in a part of field and are transferred in the whole field, before or after transplanting.
Being capable of symbiotic nitrogen fixation Azolla is an excellent biofertilizer. In fact, in different researches it was found that the yield of rice was increased by 20-30% when incorporated with Azolla.
Biogas production capacity of Azolla is also exploited nowadays. To the fact that anaerobic digestion of Azolla with crop straws give good results of methane gas production.
Azolla plant can form a thick layer on water surfaces, so it uses for weed control in paddy farm. In paddy farm, Azolla forms a thick layer and cover all farm area and work as organic mulching which doesn’t allow to produce weed. also it slow water evaporation rate and maintain soil moisture for a long time.
Azolla has another ability Azolla restrict mosquito breeding process, and thus Azolla also called as mosquito fern.
- Feed for livestock poultry and fish
Feed for livestock Azolla contains very high proteins, amino acids, vitamins (vitamin A, vitamin B12, Beta Carotene) and minerals, so it is the excellent nutrient feed for livestock. Also, Azolla has low lignin content. So animals easily digest. Mixing some amount of dairy feed with Azolla enriches the nutritional value of feed. Moreover, direct feeding of livestocks with green Azolla in dry seasons is also a good practice. It is observed that feeding Azolla to poultry birds improves the weight of broiler chicken and increases the egg production of layers’ birds. also in animals, it showed an overall increase of milk yield by 15–20% when 1.5–2 Kg of Azolla was combined with regular feed. Azolla can be fed to sheep, goat, pig, rabbit, and fish. It is highly nutritious and cheap source of fish feed with high protein content. The high level of crude protein of Azolla and higher lysine concentration indicated that Azolla plants may be a good source of fish feed.