Transforming Urban Waste Products into Gardening Aids in the Humid Tropics

Antony Santiago

A wide variety of urban waste products are available for transforming into gardening aids in the humid tropics where countries such as Malaysia are situated. Every household produces kitchen and garden wastes which are packed in plastic bags and dumped on the roadside for the urban authorities to transport to the many land fills scattered around urban areas. Similarly discarded half shells of coconuts are available by the lorry load from wet markets and factories producing copra. Then there are worn out tyres which are piled up in front of automobile workshops which create and unpleasant sight and are difficult to dispose.

The writer was interested in using these urban wastes and conducted a series of experiments to transform them into raw materials to aid gardening and to study the potential for developing new urban practices and industries that favour the environment.

To have a successful garden it is essential that one has the right type of soil conditions, proper aeration and irrigation and the desired type of environment for the plants grown. All these conditions may be provided by using kitchen and garden waste, coconut shells and tyres for growing the plants in containers.

Tyres

In 1985 the writer went to Holland to present a paper at a conference on horticulture in Wageningen. There he took the opportunity to visit Leiden where he saw ornamental plants grown both in Wageningen and Leiden in large tub-like containers in the urban environment.

The author then remembered that village folk in Malaysia who did the same thing with discarded tyres while others improvised a variety of discarded containers to be used for growing plants. These improvised containers included discarded kerosene tins, oil cans, pails and spittoons.

On his return to Kuala Lumpur, Malaysia he observed at a tyre vendor’s store where a tyre mechanic working on cutting worn and discarded tyres to sell as scrap rubber to cobblers who would use the material to fix on to soles of shoes. He had cut the belly part of the tyre with relative ease with a kitchen knife dipped into a pail of water in order to make the act of cutting easier.

These observations gave him the idea of improvising worn and discarded rubber tyres for use as containers for composting soil and making suitable soil mixtures and growing garden plants around his home in Bukit Bandaraya, Kuala Lumpur, Malaysia. After successfully using tyres as aids for soil composting and growing many types of garden plants in tyres the writer feels worn and discarded tyres can be put to better use instead of filling already overcrowded landfills.

Cutting the tyre into several useful parts for gardening use

A pneumatic tyre meant to fit the wheels of a vehicle may be considered to have three parts namely the rim, the belly and the tread. When the rim and the belly of one side of the tyre is cut, this results in a tyre pan . When both sides are cut in the same way the tyre results in a tyre ring. The tyre pans and tyre rings are stacked one over the other to improvise the containers. When the tyre rings alone are stacked one over the other the result is a container suitable for soil composting. Garden waste including grass clippings, weeds and kitchen waste are laid in alternate layers within the container for soil composting waste Subsequently the next tyre will have the rim and belly removed to produce a tyre ring which will be then placed on the tyre pan. Subsequent tyre rings are stacked according to the desired height.

The tyre stack which can be anything from one tyre to seven or eight tyres high and can be used as a container for composting or for growing plants.

The cut rims of tyres can be also tied with with nylon rope to result in wicker like balls which can be lashed to each other to make bigger wicker like balls that can be rolled into shallow seas for growing algae and to protect the young of inhabitants of the sea from predation for eventual harvest by man for food.

There are many other possibilities to conduct experiments on the use of cut parts of discarded tyres which include road barriers filled with ornamental plants and the like.

Kitchen and Garden Waste

According to one American professor by the name Edgar Henderson of the University of Missouri most of the cultivated plants in Central America were grown near dump heaps of the farming communities there. Professor Henderson in his book entitled Introgressive Hybridization explained how the natives of Papua New Guinea grew food crops such as sweet potatoes, yams and tapioca in dump heaps.

The same is true of farming communities in Malaysia and Indonesia who grow banana and papaya trees near dump heaps. In other communities, female members would grow vegetables near the kitchen where they could easily water them and provide nutrients in the form of kitchen waste such as egg shells and onion peelings.

In preparing a soil mixture made out of kitchen waste such as fish innards, scales, shrimp shells, papaya skin, washings and garden waste such as leaves, grass and twigs are thrown into a tyre stack and a layer of soil put on top of it in the ratio of 30% waste and 70% soil. These layers are added on over time until it reaches a height of five to six stacks of tyres which can then be left to stand over three months. Water can be added during dry months and urea crystals may be added on the top most layer from time to time. After three months, the compost should have sufficiently settled to be used as planting material. No other fertilizer or soil needs to be added for this perfect soil mixture.

Coconut Shells

Used coconut shells that have been stripped of its husk and the inner pulp used up as food what remains will be empty half shells. These will make excellent soil aeration devices during the dry season and water retention devices during the wet season.

One half shell will have eyes or holes which would have served as the exit points for the germination of the coconut seedlings while the other half shell has a closed wall. Two half shells with holes are put close together to resemble a ball while another two half shells with a closed wall are cupped one on top and one below the ball. This forms a single unit of the device which looks like a ball made out of four coconut shells which are full of air. These devices are placed 20 centimeters below the soil and placed 20 centimeters apart from each other in a trough. The saplings are placed on top of the devices and then covered with soil.

Air is needed in the soil for biological processes to work whereas water is needed by the plants for photosynthesis. This device provides both. During the dry season the devices are full of air. During the wet season, the air is driven out of the device and in its place is filled with rain water.