Composting Conundrums

PENCINTA ALAM JULY 2009
GREEN LIVING COLUMN

COMPOSTING CONUNDRUMS
By Wong Ee Lynn



Composting has the following benefits over conventional means of disposing of household and garden waste:
1. Can be used as fertilizer and mulch to improve soil quality;
2. Reduces the volume of rubbish disposed of, and consequently, the fuel used to transport rubbish to landfills.
3. Reduces the amount of organic waste being sent to landfills, thus reducing the amount of methane generated in landfills as a result of the decomposition of large amounts of organic matter.

Here are some questions posed to Green Living by those who have attempted household composting:

Q: WHAT CAN I DO WITH MEAT, FOOD WASTE AND PET WASTE? CAN I ALSO COMPOST THESE IF I LIVE IN AN APARTMENT, OR COMPOST USING A BIN OR POT?

The general advice is that you should not put pet waste or anything greasy, cooked or meat-based into a compost pile, unless you have a special composter (such as Green Cone, or a compost aerator). However, these composting devices are expensive and not easily available in Malaysia. Furthermore, as the purpose of composting is to reduce waste, it would not make sense to increase consumption by purchasing another product.

Composting advocates and practitioners advise the following steps to ensure that any organic matter that is included in your compost pit decomposes quickly without contaminating the rest of the compost:
i. Most wet waste such as fruit and vegetable matter should be evenly spread out within the compost pile, skin-side down, to ensure rapid drying. It is best to chop or break up larger pieces.
ii. Maintain a good proportion of wet waste, dry waste and aged compost. Do not put too much wet waste in at any given time.
iii. Expose all food waste to sunshine to speed up the decomposition process and to eliminate odours. To prevent flies and snails, cover the wet waste with a light layer of soil or aged compost, or cover the compost pit/bin with a mosquito screen to keep insects out.
iv. It is best not to compost fat, gristle and organs from animal carcasses. Most worms will not aid in the decomposition of anything with oil or fat. Meat and grease also tend to attract scavenging animals and flies. All bones that are to be composted should be thoroughly cooked and stripped free of meat to prevent bacterial and maggot infestation. Bury the bones deep within a pocket of dry and aged compost in the compost pile. Be prepared to take a longer time before you can turn the compost.
v. Composting meat and bones works best for those with large compost pits in landed areas, and is less suitable for those living in apartments or composting using bins or pots. This is because microorganisms in soil will help meat and bone waste break down more easily. Also, balcony compost pots/bins may not receive sufficient heat and sunlight to kill bacteria.
vi. It is best to burn or char bones and meat waste to kill bacteria, but it will not make sense to start the oven or grill just to burn waste for inclusion in compost. Burn the bones and meat in an existing fire, e.g. a barbecue pit at the end of a party before the coals die out.
vii. To be on the safe side, compost your meat/bone waste in a separate site from your existing compost pit. This is because if the decomposition process is not complete, there will be highly dangerous bacteria in your meat and bone waste that will contaminate the rest of your compost. When your meat-based compost is completely dry and odourless and there are no recognisable pieces of meat/bone scraps in the compost, it is ready for use.
viii. Pet waste can be buried in soil PROVIDED it is far away from water sources and food plants (i.e. fruits and vegetables). Pet waste should only ever be buried near flower beds and non-fruit trees.
ix. Most compost practitioners recommend NOT digging up composted pet waste or meat/bone waste for use in other areas of the garden, but to leave it in the soil where it is buried. This means that the composting was carried out to reduce waste and to improve soil quality, but is not intended to be a method of producing compost fertiliser to be used in potted plants or other parts of the home or garden.
x. Local environments and soil quality differ, so you might not be able to compost meat or pet waste as successfully as your friends who live in different areas. Weather also plays a factor in how quickly decomposition takes place. It is always easier more sanitary to compost in the hot season.