Azolla is a free-floating aquatic fern. There are six species of Azolla – Azolla Carolina, Azolla nilotica, Azolla filiculoids, Azolla Mexicana, Azolla microphylla and Azolla pinnata. The Azolla Pinnata is a common species in India. But Azolla microphylla is a suitable species for quick biomass production under tropical and sub-tropical climate condition. Azolla filuculods is temperate species can be grown under temperate region. Now-a-days a cross between Azolla microphylla and Azolla filiculoids are also available in India.
Azolla filuculods is temperate species can be grown under temperate region. Now-a-days a cross between Azolla microphylla and Azolla filiculoids are also available in India. The Azolla is mainly propagated by vegetates means. It may yield on an average about 1.5kg/sq meter in a week. Under normal condition the Azolla doubles it selves in three days. Multiplying Azolla through sporocap technique has also been developed in many research institutes in the world. Azolla can be multiplied in a small cement cistern/galvanized iron tray or cellophane sheet. 
The convenient size will be 2m X 1m X 0.3m. A layer of 7-10cm of soil and cow dung is provided at the bottom. About 5 - 7cm depth of water is maintained in the pit. About 10 – 12gms of single super phosphate/rock phosphate and 2 gms of carbofuran are applied for proper nutrient and pest control. Then about 200gms of fresh Azolla is inoculated in each pit. In about 12 – 15 days 2 – 2.25kg of Azolla can be harvested.
After each harvest above mention super phosphate/rock phosphate be applied for fast multiplication of Azolla. Every time, at the time of harvest 200gms of Azolla is left over in each pit for further multiplication Azolla is found to be very nutrient and less expensive organic feed supplement for dairy animals, goats and poultry. After harvest of Azolla from the pit it can be washed thoroughly with fresh water and kept in a bucket half filled with water. Fresh Azolla is fed as such to cows and goats but for poultry Azolla is fed with commercial feed 1:1 ratio. For goat 400 – 500 gms and for cow 1.5 – 2.00 kgs of fresh Azolla can be fed with a mixture of commercial feed or green fodder. 
By feeding Azolla there will be substantial increase milk and meat yield. Azolla has also been extensively used as feed for pig, duck and fish. Because it contains high protein (24 – 30% on dry weight basis and 4-5% nitrogen). Besides this there are so many important nutrients present which is very much helpful for animal feed as well as nutrient for plants. The chemical composition in Azolla (dry wt%) is, Ash-10.5, soluble sugar 3.5, crude protein 24-30, Nitrogen 4-5, Phosphorus 0.5-0.9, Potassium 2.0-4.5, Calcium 0.4-1.0, Magnesium 0.5-0.6, Manganese 0.11-0.16, Iron 0.06, Chlorophyll 0.34-0.55. 
Chlorophyll 0.34-0.55. Since Azolla releases plant hormones and vitamins and also contain high percentage of Nitrogen, Phosphate and Potash, so it can be used for Azolla – Vermi bio-wash. Besides Azolla Vermi cast the Azolla Vermi wash can be sprayed as a foliar nutrient

Azolla is a free – floating aquatic fern. There are six species of Azolla

1.       Azolla Carolina

2.       Azolla nilotica

3.       Azolla filiculoids

4.       Azolla Mexicana

5.       Azolla microphylla

6.       Azolla pinnata.


Potential fertilizer for its:

  1. High N-fixing ability
  2. High biomass due to rapid growth
  3. Scavenger of K
  4. Sollubilise Zn, Fe,Mu.
  5. Improves soil physico-chemical properties.
  6. If applied together, the utilization efficiency of urea increases.
  7. Thick Azolla mat control weed growth.
  8. Produce compost with a rich, more constantly releasable supply of plant available N. narrow down C: N ratio for better decomposition.
  9. Extract P from eutrophicated water (average P content of soil should be 25 pm to support growth).
  10. It releases plant hormones and vitamins.



  • From other uses
  1. Check evaporation loss of water from rice field 45000 lit/crop/ha.
  2. Absorbing heavy metals from polluted water
  3. Feeding livestock’s, poultry, birds and fishes.
  4. As carrier for microbial cultures (bio fertilizers ).
  5. Source of biogas.

Mass production of Azolla.


  • Prepare the field uniformly and level it.
  • Divide the field into several 20 m X 20 m plots by providing suitable mud bunds and irrigation channels.
  • Water up to the depth of 10 cm.
  • Mix cow dung @ 10kg. Per 20 liter of water.
  • Add 100gm. Of super phosphate in three split doses at

          4 days intervals.

  • Inoculate fresh Azolla @ 8 Kg. per plot.
  • Add furadan granules for insect pest control at the 7th day after inoculation @ 100 gr. Per plot.
  • After 15 days, generally 80-100 Kg. fresh Azolla is harvested from each plot.
  • Again inoculate fresh Azolla after adding cow dung, super phosphate and follow the same procedure.

Production Technology of Azolla

Mass Production of Azolla:

  • The vegetative growth is involved.
  • The stem grows by an apical cell with three cutting faces.
  • Azolla has an unique ability to grow fast.
  • For most spp. Doubling time is 2-10 days.   


Determining Factors for Growth are:

  • Temperature, light, day length, nutrients, salinity, pH, atmospheric humidity desiccation, wind, plant density, predators, pest, species.
  • Phosphorus nutrition plays an important role.
  • Phosphorus level at 20 ppm produced more biomass than lower level.
  • The average P-content of the soil which supports the fern growth well is 25 ppm.
  • Maximum biomass yield range from 0.8-5.2 t dry matter per ha.


Growth Affecting Factors of Azolla :


  • 25-30 C is optimum for most species but at field level survive well between 15-35 C, A. caroliniana, A. microphylla, A. nilotica and some varieties of A. pinnata are relatively tolerant to high temperature.



  • Growth under field condition is maximum at 50K lux. In summer season also the Azolla growth is affected highly because of the bright sunlight. A simple thatching by coconut palm/ Palmyra palm leaf can save the Azolla in the hot summer.


Soil pH and Salinity

  • The average ph for successful growth of Azolla is 4.5-8, optimum 5-7.0. A. caroliniana was found to have a wide tolerance for both ph and salinity.


  • This plant is very sensitive to dryness. To get successful growth of Azolla we need that much water level where Azolla can float. Under moist soil condition also Azolla survives.


  • The nutrient requirement for Azolla is like other ferns.


The main pests are species of



Nimphula and Chlronomus


Common pesticides like


Furadon (50gm/100Kg. Fresh Azolla)


Fungal infection


Rhizoctonia solani

Fusarium sp.

Sclerotium sp

Rhizopus sp


Common fungicides e.g.


Bavistin ( 1 gm./l)


No. Composition Composition on the basis of dry wt. (%)
1. Ash 10.5
2. Crude fiber 9.1
3. Crude fat 3.0-3.3
4. Starch 6.5
5. Soluble sugar 3.5
6. Crude protein 24.0 – 30.0
7. Nitrogen 4.0 - 5.0
8. Phosphorus 0.5 – 0.9
9. Potassium 2.0 – 4.5
10. Calcium 0.4 – 1.0
11. Magnesium 0.5 – 0.6
12. Manganese 0.11 – 0.16
13. Iron 0.06
14. Chlorophyll 0.34 – 0.5