Effective Microorganism (EM) is a versatile product that contains microorganisms found in all ecosystems. This product is widely used in sustainable environment management. The principle of EM is the conversion of a degraded ecosystem which is full of harmful microbes, to a productive ecosystem that contains useful microorganisms.
EM is a liquid concentrate that respects nature and does not contain genetically engineered microbes.
The concentrate of selected species of microorganisms includes predominant populations of lactic acid bacteria, yeast, photosynthetic bacteria, smaller quantities of actinomycetes, fermenting fungi and other types.
All of these microorganisms are mutually compatible with one another and coexist in liquid culture. They are collected from the natural environment of our country, making EM an indigenous product. Concentrated EM (EM 1) solution is available from the manufacturer (Maple Orgtech) in India. The technology was developed at the University of Ryukyus, Okinawa, Japan in 1982 by Dr. Teruo Higa.
EM usage covers a vast number of areas like agriculture, poultry, animal husbandry, aquaculture, solid and liquid waste management and environmental hygiene. At our campus we use EM technology for effluent treatment in recycling sewage effluent, food waste treatment by transforming waste into organic compost and cleaning bathrooms.
EM 1 is activated by the following procedure used for application in effluent treatment: One kg of jaggery is dissolved in 19 liters of water. After filtering this mixture, one liter of EM 1 is added to the jaggery water, and the solution is kept in a closed container for five days. This solution is called extended EM. Four kg of Zeolite (sodium aluminium silicate) is put in a container and drops of extended EM are added. The resultant product is called EM Bokashi, a Japanese word meaning "fermented".
It is mixed thoroughly until the material becomes a paste. The paste is then shaped into balls weighing 100 g each. Each ball is covered with green leaf (Banana or Teak), put in closed polythene bags and kept within closed plastic containers for four to five days to allow fermentation. After fermentation, these balls are called EM Bokashi.
Three tons of vermicompost, prepared every month at our campus, acts as an excellent organic fertilizer for horticulture plants and crops. Vermicomposting or composting using earthworms is also an efficient technique for recycling and reuse of organic wastes.
Backyard wastes, litter fall, crop residues and other vegetable wastes can be recycled by using this technique; the resultant product is utilized as organic manure for crop cultivation.
VCompared with garden compost, vermicompost is richer in major nutrients (NPK) and micronutrients such as Cu, Zn, Mn, Fe. Nitrate nitrogen is found to be 5.6 times higher in vermicompost than garden compost, while other nutrients such as sodium, potassium, calcium are 1.5 – 2 times higher.
Vermicompost is also used as an adsorbent to remove heavy metals such as Cd(II), Cu(II), Pb(II) and Zn(II) ions laboratory effluents. (Matos and Arruda 2003).
Around the world, experiments are being conducted on several earthworm species with respect to compost material and application of vermicompost. Comparative studies to evaluate composting potential by Eisenia foetida(non-native) and Lempito mauritii (endemic) species were performed by Tripathi and Bharadawaj (2004) in the semiarid environment of Jodphur district of Rajasthan in India.
Overall observations indicate E. foetida may be a more efficient breeder than L.mauritii in the desert region of Rajasthan. Eisenia foetida is the most common worm used for vermicomposting, which feeds on the compost pile from the bottom.
Preparation of Vermicompost at Amrita Vishwa Vidyapeetham
Leaf litter, dry leaves, weeds and crops residues obtained from the campus and farms are fully converted into compost and vermicompost. These materials are allowed to decompose for 60 days by placing in heaps and sprinkling frequently with water and cow dung slurry. The decomposed material is then vermicomposted in sheds, utilizing earthworms (Eisenia foetida). The sheds are covered completely with green shade nets to reduce light intensity as the worms are extremely sensitive to light. The compost is heaped in stages to a height of 60 cm and sprinkled with water and cow dung slurry. Vermicomposting is completed in 10 to 15 days.