EM stands for effective microorganisms and the technology implies the use of liquid culture of beneficial microorganisms produced through natural fermentation and not chemically synthesized or genetically engineered. It is an eco-friendly and safe technology that offers solution to the problems which may otherwise be experienced while handling the organic wastes.
EM is a consortium of photosynthetic bacteria, lactobacilli, yeast, fungi and actinomycetes that work symbiotically to counter pathogens and provide environment friendly solution to convert waste into organic fertilizer. These organisms mainly sourced from nature can be both aerobic and anaerobic. Anaerobic microorganisms aerate the anaerobic zone in windrow that creates oxygen for aerobic microorganisms. Each group of microorganism has a responsive function to perform. Some of the EM microorganisms include members of genus Rhodopseudomonas, Rhodospirillum, Rhodobacter, Lactobacillus, Candida, Saccharomyces, Streptomyces, Azotobacter, Azospirillum, Bacillus, Pseudomonas, Xanthomonas, Aspergillus, Penicillium, Trichoderma, Phanerochaete etc.
The Phototropic bacteria synthesize amino acids, nucleic acids, bioactive substances and sugars from secretions of organic matter using sunlight as the source of energy. They consume carbon dioxide, other toxins and pollutants and excrete oxygen. The metabolites developed by these microorganisms act a substrate for increasing beneficial microbial population. Lactic acid bacteria produce lactic acid from sugars. Being a strong sterilizing compound its production suppresses harmful microorganisms. They also control the propagation and spread of pathogenic fungus such as Fusarium and reduce the population of nematodes. Lactic acid also promotes the fermentation and decomposition of lignin and cellulose. Yeast synthesises hormones and enzymes that promote active cell and root division and is harmless to human health. Filamentous fungi by production of hydrolytic enzymes decompose the cellulolytic biomass.
EM culture known as EM bokashi can be effectively used to convert organic wastes into high quality compost to be used as a fertilizer. EM bokashi is fermented organic matter and works as a compost starter. It is made from carbon rich organic substrate as rice bran/ wheat bran/ saw dust, molasses, water and EM solution. To prepare one litre of EM solution (accelerator), 10 ml of EM is added to 40 ml of organic jaggery (molasses) and 950 ml of water. Mixture is placed in air tight container and left in shaded place to ferment for 5-10 days depending upon the temperature. Gas formed is released in between and when pH drops to < 4.0, activated EM solution is ready to use. One to two litres of activated EM solution is sufficient for material in 1 m3 pit. The rate of activated EM solution (EMa) may vary depending upon the type and quantity of material to be composted. As the ideal microbial composition of EM a will deteriorate over time, it should be used up within one month.
The raw material to be composted may include residual food organics, garden and agriculture organics, wood and timber residues and bio-solids. For composting of agricultural residues as straw, it is stacked in 0.5 m layers in a pit (1 m3 size) with low walls. The size/ dimension of pit may vary. The substrate is sprinkled with water for sufficient moisture content. It is followed by stacking of 5 cm layer of FYM. Nitrogen rich waste/ urea (@ 100-200 g) can be added to reduce the initial high C: N ratio of substrate. EMa is sprinkled during build-up of the compost pit/ heap, layer by layer till the heap is complete or pit is full. For better fermentation maintain moisture between 40-60%. Cover with plastic sheet. If temperature reaches 60oC, give turning to avoid the inactivation of flora responsible for organic matter decomposition. In general, a turning is required after 18-20 days to boost the aerobic decomposition. The fertilizer is ready to use a couple of weeks later. EM solution functioning as an accelerator reduces the composting period by 3-4 weeks.
This compost has stable C: N ratio and microbial activity and diversity are far greater than untreated compost. There is efficient conversion of organic nitrogen to nitrate. Organic matter decomposition rate is also accelerated. This type of compost can and should be used very fast to achieve the maximum benefit from the organisms inoculated into the heap/pit. The fact that lots of organic matter may not yet be decomposed is desirable in this case, as the propagation and metabolic activity of the organisms depends on the availability of carbon from organic matter.
• EM not only helps to expedite the natural composting process but also reduces the foul odour and pests. EM bacteria consume sulphur reducing bacteria that produce H2S resulting from the breakdown of organic matter in the absence of oxygen and suppress pathogenic growth associated with composting
• The EM fermented waste is supplemented with useful microorganisms which makes the compost imminently suitable for agricultural use.
• EM has great potential to be integrated in promoting sustainable agriculture system.
• EM technology is not only environment friendly but also protects the environment.
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