The Sunday Mail
Farmers in Hwedza are reaping the fruits of embracing earthworm technology in their organic farming enterprises.
They are harvesting and selling tomatoes on a daily basis from greenhouse and open field gardens where they are relying solely on organic compost produced from using earthworms. The Zimbabwe agriculture extension service (Agritex) has helped in establishing demonstrations on these farmer’s gardens.
The farmers’ operations have now been certified as organic by the Zimbabwe Organic Producers and Promoters Association (ZOPPA).
This could pave the way for the exportation of this organic produce which is now in high demand in foreign markets. Before the introduction of earthworm technology farmers and gardeners used mutsakwani or cattle dung manure to fertilise their soils.
The farmers were later introduced to vermi-compost (earthworm compost). Vermi-compost is a product of decomposing organic waste using earthworms. It is in fact earthworm castings and excreta. It has been demonstrated to be more potent than ordinary compost and animal manures.
Earthworms are known to restore and improve soil fertility and significantly boost crop productivity.
Their excreta (vermicast) is a nutritive organic fertiliser rich in humus, macronutrients, micronutrients, beneficial soil microbes — nitrogen-fixing and phosphate solubilizing bacteria and actinomycetes and growth hormones auxins, gibberellins and cytokinins.
Earthworms and their vermicast and body liquid (vermiwash) are scientifically proven as both growth promoters and protectors for crops or plants.
In experiments carried out in Australia with maize, wheat, tomato and egg-plants, vermi-compost displayed excellent growth performances in terms of height, colour, texture of leaves, appearance of flowers and fruits, as compared to chemical fertilisers and conventional compost.
There was also less incidences of pest or disease attack and reduced demand for irrigation in plants grown on vermi-compost.
Presence of live earthworms in soil also makes significant difference in flower and fruit formation in vegetable crops.
Composts work as a slow-release fertiliser whereas chemical fertilisers release their nutrients rather quickly into the soil and soon get depleted.
Significant amount of chemical nitrogen is lost from soil due to oxidation in sunlight.
However, with application of vermi-compost the organic nitrogen tends to be released much faster from the excreted humus by worms and those mineralised by them and the net overall efficiency of nitrogen is considerably greater than that of chemical fertilisers.
Availability of phosphorus is sometimes much greater.
The study in Australia showed that earthworms and vermi-compost can promote growth from 50 to 100 percent over conventional compost and 30 to 40 percent over chemical fertilisers besides protecting the soil and the agro-ecosystem while producing nutritive and tasty food at a much economical cost (at least 50-75 percent less) as compared to conventional fertilisers.
Hwedza has traditionally been importing tomatoes from Mbare Musika, Nyanga, Mutoko and other areas. The earthworm technology supported by greenhouses and drip irrigation may soon make Hwedza an exporter of organic tomatoes and other vegetables.
Growing crops organically is much cheaper and preserves the integrity of the soil.
As a country we desperately need to augment convectional fertilizers as supply is not always adequate. Organic produce gives the country an opportunity to enter the lucrative export market.
For further details contact the writer by email at [email protected]
