Azolla

 

Azolla

 

Azolla is a genus under plant kingdom consisting of seven species of aquatic fern belonging to the family Salviniaceae. Azolla is the genus of aquatic ferns but they look nothing like a typical fern due to their extremely reduced form.

 

They are free-floating fern that lives in symbiotic association with Nitrogen fixing blue-green algae that has the potential to produce 50-60 kg/ nitrogen per hectare under suitable conditions. Not just adding nitrogen but being bulky they add organic matter to the soil thus improving the soil structure. They are very productive and can produce biomass by two folds in 2-3 days. Azolla has once considered has invasive weed but after realising its benefits they are fondly cultivated by farmers. Azolla is one of the most commonly used bio-fertilizer by farmers as they are easy to cultivate in the field. Azolla is not only used as a bio-fertilizer but they are also loved by poultry and cattle as feed. Azolla is rich in protein, essential amino acids, vitamins, and minerals which make them qualify as a superfood for cattle and poultry.

 

Cultivation of Azolla:

 

Azolla caroliniana,Azolla filiculoides, Azolla Mexicana, Azolla microphylla, Azolla pinnata, and Azolla rubra are the seven species of Azolla that are known. Out of which Azolla pinnata is the most common species in India and cultivated by the farmers.

 

Step 1:

 A suitable site should be selected preferably under a tree otherwise a shed has to be constructed. A pit with convenient size (2mx2mx2m) should be dugout. Make sure that the level pit is properly maintained so that the level of water can be maintained.

 

Step 2:

The pit should be covered with plastic gunnies to prevent the roots of the nearby trees from piercing the silpauline sheet, which is spread over the plastic gunnies. Silpauline is a lightweight, waterproof sheet that is resistant to UV rays.

 

Step 3: Spread around 10 kg of fertile soil on the bottom of the pit. Then add slurry made of cow dung .20-30 g of superphosphate can be also added while making the slurry. Fill the pit with more water.

 

Step 4:

Place 0.5-1 kg mother culture of Azolla into the pit. This will propagate very fast and they will pit in the next 10-15 days. Then they can be harvested every day at the rate of 500g/day.

 

Step 5:

Slurry made with 1 kg cow dung and 20g superphosphate should be added after every 5 days of harvest to provide enough nutrients in order to maintain the continuous multiplication of Azolla.

 

The addition of micronutrients like magnesium, iron, copper, sulfur at weekly intervals is recommended to enhance the mineral content of Azolla.