The Department of Agricultural Research in the Botswana
Ministry of Agriculture has started producing vermicompost fertilizer from earthworms or red worms, scientifically known as Eisenia Fetida. The project, which started last year July, targets backyard gardeners.
The Principal Technical Assistant in the department, Elias Ramabu, explained to Gazette Business while exhibiting at the just ended Agriculture show how a pre-compost application is done.
“The manure is put in a trench, watered twice a week, covered with a black plastic sheet to protect the moisture for at least one month; then earthworms are introduced using different manures horse, pig or cattle - and wait for a period of at least four months or more; the vermicompost will be ready for harvest, depending on the population of the worms.”
He said each worm produces 21 eggs and each egg produces three worms, therefore if the environment is conducive, the production becomes high. “We import our worms from South Africa, with 1.2 tonnes worth P27,000 (P500 per 250grams); we harvested four tonnes mid-April and we are still multiplying our earthworms,” he said.
Research is yet to be carried out on how crops respond to the fertilizer; then the department will start producing the vermicompost to sell to the public or supply farmers.
Ramabu said this year’s agricultural show was their first chance to educate the public about the natural fertilizer. “We will continue with public education and also train farmers on how to produce and manage the vermicompost; we hope Batswana will tap into it for their future benefit. We want them to produce their own organic fertilizer as it is healthy and cheap, and one only needs animal manure, as opposed to inorganic fertilizer, which is very expensive to buy,” he added. Animal farmers could also benefit as they would sell their compost/animal manure to people who use earthworms.
The challenges encountered are that government does not find it easy to secure manure sources for the compost. “Not many people keep horses and pigs as opposed to cattle; however we are able to source dairy manure from Sunny Side dairy farm,” Ramabu said.
One aspiring farmer who is also a backyard gardener, Thabo Mapilo, said: “I am very excited for I have learnt how to produce the vermicompost; it is cheaper compared to fertilizers from the shops, which are expensive to buy.”
Mapilo grows spinach, rape, tomatoes and onions for his family’s consumption to avoid buying vegetables from shops.
Eisenia Fetida are the most commonly used variety of composting worm. They are generally 2-4 inches in length with a reddish/purple colour, but their appearance and overall physical characteristics can actually vary quite considerably. They can range in colour from a light orange all the way to dark purple, sometimes with stripes, or not. One characteristic that seems to be fairly consistent is the yellow tail tip.
Red worms are very tolerant of a wide range of temperatures – from freezing to 35 Celsius; so they do very well indoors and outdoors.