Following is a simple way of harvesting IMOs by Rohin Dsouza and Rico Zook (www.i-permaculture.org).
1. Non metal container with a lid/cover
2. Day old cooked rice
4. Molasses, jaggery, whole sugar
Harvesting the IMOs
1. Loosely fill the cooked rice in a non metal container and cover with a lid so that there is some space to air to pass through but not enough for the insects to get in.
In our case, we used empty coconut shells and tied the two halves together. We are also trying banana leaves as they can hold a bigger chunk of rice.
Split bamboo pieces are also commonly used.
2. The rice should be firm so that it has air around it. The rice can be moistened just a bit before its filled in. Soft rice with too much water will not allow room for breathing.
3. Bury the container/shells with rice in a moist place that has good rich soil, such the top of the container is just below soil surface. Moisten the soil if necessary but do not pack the soil. Access to air is crucial. If air temperature is cold a place in the sun might be suitable, like a shaded place if the sun outside is too intense. Mark the spot for easy identification.
The place of harvesting will determine the dominant microorganisms that will grow on the rice. Rice buried in a forest will potentially have more fungi than bacteria. Plant specific microorganisms can be harvested by burying the rice close to the growing plant or in a heap of freshly cut plant.
4. Wait 5 to 10 days depending on soil temperature and richness of soil. If necessary keep soil moist during this time.
5. Dig Up and Open. If it worked you will find moulds of different colours, some fuzzy, some not, giving the sweet fermented smell. These are the IMOs feeding on the rice.
If it stinks putrid and turns the nose it has gone anaerobic and should be thrown out since it wont be of much use. If it smells ok but does not have much growth it can be closed back up and reburied for a longer time.
Multiplying the IMOs
6. In non metal bucket mix molasses or raw sugar (about the same weight as the rice) with tepid water (not hot or cold to touch). We need a rich mix of molasses and water to begin with, so be careful with how much water you add.
7. Add the moulded rice to the liquid mixture. Break up all clumps well and stir mixture thoroughly so all grains are individuals. Finished mixture will be like thick soup.
8. Cover the bucket/container with a newspaper, old cloth or any other breathable sheet.This is to keep insects and unwanted animals out while still allowing oxygen in. Place bucket in a quiet place at room temperature out of the direct sun.
9. Wait 5 to 10 Days depending on room temperature.
10. When ready it will have the sweet fermented smell. It should also be very fuzzy. If not fuzzy enough and/or smell is weak, recover and wait some more days. If it has stinky putrid smell throw out and try again.
Using an old cloth or net strain well to remove all rice particles. Refrigerate liquid or store in cool/cold dry place out of sun but with access to air. Depending on the storage, this culture will last 4 to 8 weeks. If a culture is stored for long, more sugar should be added to the culture to keep the IMOs from starving. After awhile the strain will weaken and you will need to harvest a new batch.
1. These IMos can be diluted with water (1:10 for mature plants and 1:20 for young, sensitive plants) and sprayed on the soil or leaves for growth promotion and helping fight diseases.
2. They can be added to compost and greywater systems to accelerate decomposition and prevent bad odours from decomposing material.