Earthworms and their benefits to the farmer
Earthworms are one of the most useful organisms to be found in soil. With over 4000 species worldwide it is little wonder that research has only been done on about 15 species. The most common variety is `Eisenia foetida` or `Red Wriggler` as it is commonly known. Some call this variety `Kariba` worms .
The reason for using this earthworm in composting is that it can stand temperatures from 0 deg. C. up to about 36 deg. C., it breeds very quickly, doubling it's population every 30 to 60 days, and lives above ground in any organic matter. This, together with its ability to maintain a high population density, makes it ideal for earthworm farming.
The presence of earthworms in the soil are an indication of good healthy soil which is rich in organic matter. The ideal earthworm count are 250 to 300 per sq. m . and that will give you, on top of other nutrients, 80 to 100 kg N per Ha. for free . Cultivation does not affect their population but cultivation depletes the soil of organic matter which in turn starve the earthworms and reduce their population. The earthworms positive impact on the population of other organisms like bacteria, actetemicide and fungus is also an important factor for good healthy soil.