Azolla , known to many people as Azolla, scientific name is Azolla spp., is in the family Azollaceae. In Thailand, there is a native species called Azolla Pinnata (A. pinnata), which is small and low yielding. The Department of Agriculture has brought in varieties from abroad to improve. until the species Azolla microphylla (A. microphylla) yields 10 times higher than the native species.
Many people define Azolla as a biological nitrogen fertilizer plant. Through the nitrogen fixation process from the air of blue-green algae up to 300-600 kg/rai per day, azolla contains 3-5% of the dry weight of nitrogen as a constituent. If the Azolla is planted 1 rai, the green manure is equivalent to 7-10 kg of urea fertilizer.
Although the Azolla is a small group of water ferns. But the benefits of Azolla are so great that they are really overdone. On the other hand, the process of cultivation, care and propagation is not that difficult. Most of the Azolla floats on the water surface and can grow well in the water that is not very deep, so the pond does not need to be too deep. Or you can choose a container that is suitable for use in a limited space, such as a basin or a lotus pot. This should be considered as appropriate for that area.
Techniques and procedures for cultivating 1. Prepare the place and containers for cultivation by choosing a place that has a shady Get about 40-50% of sunlight or if it’s an outdoor area or sunny. There should be a 40-60% saran camouflage.
2. Prepare 4 parts soil + 1 part manure (4:1). It can be a sack of soil that you can find at an agricultural store. and animal manure as earthworm droppings, pig droppings, chicken droppings or cow droppings pellets. that can be found and easy to use
3. Then mix the ingredients together. Pour it into a container or soil lined with plastic. to a height of about 5-10 cm.
4. Fill the soil with water about 10 centimeters, then leave it for 1-2 nights (this step, if there are photosynthetic microorganisms can be added. to accelerate the decomposition of manure)
5. Scoop out any floating debris.
6. Put the fresh Azolla into the satisfied amount. If you put a large amount This will increase the growth of the Azolla to fill the pond faster. Here it is recommended to put about 50-60% of the cultivation area is enough.
7. After about 1-2 weeks, the Azolla is grown and can be utilized. or can continue to breed However, the Azolla should not be too dense. Because it may cause the Azolla at the bottom to not receive light. cause rot and a hiding place for worms and insects
pest disease and management
Caterpillars, biting insects, sucking insects, these are the main enemies of the Azolla. Which will be destroyed by eating and sucking the sap from the leaves. It is easy to notice that the Azolla clumps together. By the method of management, a net can be made to prevent worms and insects from laying eggs. Or scoop the Azolla out and put it in the sun immediately. This method also helps to keep the Azolla for longer use. The use of insecticide sprays is not recommended. Because the leaves of the Azolla have properties like lotus or bonsai. Makes it difficult for substances or water to catch on the leaves. Therefore, it is advisable to have 1-2 breeder ponds in order to prevent infestation of worms and other insects in ponds. will still be able to use the Azolla from the mother pond to expand
Azolla needs macronutrients like other green plants. except nitrogen Including the need for micronutrients for growth, phosphorus is very necessary for Azolla. If the phosphorus content in the soil is too low This will result in decreased growth and nitrogen fixation. Therefore, about 100 grams of manure should be added every 2-3 weeks. Add more water as it may come from too much manure. make the water salty and if the azolla shows signs of turning yellow to add more manure Because the amount of nutrients may not be enough for growth.
Disadvantages of Azolla
Azolla, when propagating a lot, will cover the entire water surface. causing sunlight to not reach the bottom of the water or sunlight to reach the water affect photosynthesis and the growth of plants under water including reducing dissolved oxygen These results There is an important cause of the death of fish species easily. and should not be released to expand in the river Natural or public streams because Azolla has a high nitrogen content. and propagate quickly Overcrowding can result in spoilage and toxic water supplies.
In addition to the Azolla can be used as fertilizer and animal husbandry. Yet another benefit that many people do not know is that Azolla can be used as food. by using the Azolla that is not yet fully grown or still has a green color. The menu for the duckweed is boiled with chili paste. Stir-fried with pork/beef, Kaeng Liang, Kaeng Om, etc. However, eating Azolla should be cooked every time. Because there may be parasites or helminth eggs attached to it.
Story/Photo: Athiwat Yuachit