Huge Potential For Vermicompost In South Africa

SOUTH AFRICA - Organic recycling company Turfnet sees huge potential for vermicompost in South Africa, an organic compost that is believed to be the cleanest form of organics in the world.
The company’s organic recycling centre, in the north of Johannesburg, specialises in both vermicompost and green-matter compost.
Turfnet MD Dan Barwick says that the company’s compost is a soil amendment and not a fertiliser. The company uses a base of all organic materials made from garden refuse.
“You can take bad quality soil and only make it into a good quality soil by adding compost. This cannot be done using a synthetic fertiliser,” says Barwick.
Landscapers dump their garden refuse on the company’s site at no cost. The refuse, which consists of leaves, flowers, grass and branches, is sorted into piles of green matter and wood.
The green-matter piles are hosed down with nutrient-rich water to aid in the decomposition of the material, which is left for 45 days before a ratio of carbon to nitrogen of 20:1 is achieved. Once the material pile reaches its peak stage of decomposition, it is aerated by an industrial turner. This stage is essential as harmful ammonia is released from the compost and microbial activity is increased.
When the refuse is incinerated or dumped on landfill sites, gas emissions such as methane and nitric oxide are released into the atmosphere. Organic compost production reduces greenhouse-gas emissions through the recycling of garden refuse.
“The recycling of green matter back into soil is a huge part of preventing global warming,” says Barwick.
Meanwhile, he says that the true value of the compost lies in its bacteria content.
“The compost simply acts as a home for the bacteria and is of no value without it,” he adds.
The nutrients within the compost are broken down into a simpler form by the bacte- ria, which allow an easier uptake by plants.
The aerobic bacteria used in the cycle are bred on site in a static compost system consisting of several successive layers of grass and manure. The bacteria bred in the system are put back into the compost.
Barwick says that any well-produced and well-maintained compost pile or vermicompost box should be odourless. If the compost does have an odour, it should be of an earthy smell. He says that if decomposition becomes anaerobic from excess feedstock added to the bin in wet conditions, it will begin to smell like ammonia.
Vermicompost
The company also specialises in vermicompost, which consists mostly of worm casts, compost and decayed organic matter.
The worm cast or vermicast is the end product of the breakdown of organic matter by compost worms. Vermicompost is an excellent, nutrient- rich organic soil conditioner that contains water-soluble nutrients and bacteria, says Barwick.
The company uses two methods to farm vermicompost. The first involves the use of a windrow, which is a shallow bin containing bedding material and compost for the worms to live in. Vegetables, which are grown on site, are fed to the worms.
The second method, involves the American box model, which acts as a raised bed or flow-through system. The worms are fed across the top of the bed. An inch of castings is harvested from below by pulling a breaker bar across a large mesh screen that forms the base of the bed.
Barwick says that because the worms are surface dwellers, they are constantly moving towards the new food source. The flow-through system eliminates the need to separate worms from castings before packaging.
One ton of vermicompost is sold for R2 000; however, one handful of vericompost can be spread over a large area because of the high nutrient content.
Barwick says that not many companies have taken up vermicomposting technology and that there is huge potential for this technology as demand is picking up because of the environmental benefits.
The company employs 12 workers who ensure that all the material dumped on site goes to use. Tree cuttings are used to create bird nesting logs and feeders, while the perimeter wall of the recycling centre has been created out of large stones collected from the garden refuse and around the site. Rainwater is collected and fed through a settlement tank, which is then used to supply the green matter piles with water.
The company is supplying its products to nurseries, landscapers, farmers and golfcourses. In addition, Barwick says the company is involved in a joint venture with landscaping com- pany Top Turf in setting up an organic compost facility at leisure resort Sun City.
from Engineering News