TeleSupport India Repository

Solution Soil fertiliser using Azolla for rice farming
Country India
Last update: 13/12/2006
Summary Azolla is a fresh water fern that will grow in flooded rice fields. It is associated with a blue green alga (Anabaena azollae) that can fix nitrogen from the atmosphere. Rice fields can be seeded with Azolla in order to fertilize them. This has the advantage that requirement of inorganic fertilizer can be reduced up to 50%.

Azolla seeds are added to a flooded paddy field; after two weeks the Azolla will have spread fully in the field. The water is drained and the Azolla ploughed into the soil. By cultivating Azolla on one acre of land, 40-68 kg of nitrogen- can be added to the soil per year. This reduces the amount of inorganic fertilizer that needs to be applied. Azolla has other benefits. If rice fields are inoculated with Azolla after transplantation of rice seedlings then this will reduce damage by insects pests such as leaf folder and limit weed growth. Azolla is also edible for human beings and it can be used as a feed supplement for cattle (see 'Related GPs' tab) feedstock for biogas generation.
forum discussion 
Contributed by person details Ms. Omana Thakarprambil (RASTA, TeleSupport India)
Challenge/Issue The application of inorganic fertiliser is relatively expensive and leads to the loss of valuable farmer friendly soil organisms. Azolla is a good organic fertilizer which can reduce the cost of cultivation and also improve the soil micro-flora.
Method To watch a video of the method, in Malyalam, see the 'Publications' tab, there is as a document describing the method in English.


1) Azolla cultivation is normally done one month prior to the beginning of rice planting. The seeds of Azolla are often available in local agricultural stations and KVKs. The seeds purchased could be multiplied in a temporary tank (Link data base: ) constructed in the farmyard or in a shallow pond near the rice field.


1) After first plough in the rice field for transplantation, flood the field so that water is maintained at 5 cm depth.

2) Spread 1 kg of Azolla seed evenly to every cent (40 m2)of field.

3) The water level in the field must be maintained as 5 cm in depth.

4) Within two weeks the Azolla will have spread in the field. At the end of the third or fourth week, drain the field and then plough it to mix the Azolla into the soil along with other organic manures.

5) In summer cultivation of rice, Azolla can be added in the first weeks of December.

6) Fields can also be inoculated with Azolla @ 1kg/cent after transplanting the rice seedlings to add more N to the soil. Keep water level at at 5cm depth during the growth of Azolla. This will help the spread of another crop of azolla in the field. During weeding they will be partially buried in the soil adding fertility to the soil.
Lessons learned 1) Over 5,000 farmers in northern Kerala of south India have successfully adopted the practice of cultivating Azolla as a supplementary fertilizer in rice fields.

2) External dependency and costs of nitrogen in rice cultivation can be reduced by fertilizing with Azolla.

3) Additional labour required in this cultivation is negligible as the ploughing of Azolla into soil is done along with the second ploughing normally done for rice field preparation.

4) Water level should be maintained at 5 cm depth for the proper growth and multiplication of Azolla

5) Azolla could control weeds and pests like leaf folder when it is spread in the field after transplantation of rice seedlings.

6) Keep a small nursery of azolla in large rice fields to ensure availability of seeds.

7) Azolla cultivation in rice fields is an eco-friendly technology, important in sustainable agriculture.
List Keywords
1.1 Socio- economic Sector (OECD) 311 Agriculture
410 Environmental protection
1.2 Institutional dimension Social- livelihood systems/ Gender
1.3 Natural dimension Land/Soils
1.4 Target group(s) 1. Local communities
4. Research community
2.1 Production System Rainfed system
2. Mixed cropping system
Irrigated system
2.2 Production Chain 1. Input Supply & Use
2. Production & Management
3. Pest & Disease Control
2.3 Commodity group Food crops
2.4 Food Crops Rice (Oryza)
2.5a Agro-Ecology: Thermal zone 1: Tropical
2.5b Agro-ecology: Altitude zone Mid-altitude
2.5c Agro-Ecology: Moisture zone 2. Sub-humid
3.1 Natural Resource Mgmt. Conservation & Biodiversity
Water mgmt
3.2 Pollution-Environmental Protection 3. Ecosystems
Telesupport Themes Soil fertility
Stage Country Region Location
Development India Kerala wayanad
Test India Kerala alleppy, trivandrum
Apply India Kerala calicut, kannur, thrissur
Role Person name
Describer person details Mr. C.K Vishnudas
Role Organisation Acronym
Owner/Originator organisation details Rural Agency for Social and Technological Advancement RASTA
Network Organisation organisation details TeleSupport India Network TeleSupport India
Function Activity
Upscaling project details Biovillage
Type Title Function Download
Extension leaflet, brochure, policy brief or poster output details Azolla as a substitute for N fetiliser Description 315kb
Presentation (video, TV, radio, interview) output details Azolla cultivation in temporary tanks (video Malayalam) ' How to' manual 3.984kb
Relation Title
Related to practice details Soil fertilised using fermented cow dung
Related to practice details Cattle feed using Azolla
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