By Bhavani Prakash
Of the various recycling practices that I personally follow, the most satisfying one is converting my kitchen waste into compost - a very valuable resource for my plants. My family is often amused when I exclaim with glee at the slimy, guey, rotting vegetable and fruit waste that I collect every day and call it my precious “gold!” When the paradigm shift comes about, we will begin to see all “waste” or “garbage” as something tremendously useful for us and the environment, and realise the tragic futility of bagging it in wasteful plastic bags for landfills or incinerators.
WHAT IS COMPOSTING?
Composting is the process by which microrganisms break down complex organic matter, such as your household kitchen waste into simple and useful nutrients for the soil.
WHY COMPOST? Composting helps to
- recycle kitchen and garden waste and reduce the volume of waste going to landfills and incinerators
- convert organic matter into a valuable resource for your plants or community garden. It acts as a soil conditioner, fertiliser, a natural pesticide, an adds to humus in the soil.
- better the health of the soils. Compost breaks up clayey soil and improves their structure. In case of sandy soils, it enables water and nutrient retention. Healthier soils make for healthier plants
- mulch when used to cover soil and deter the growth of weeds
- even make some money, if there is a market for compost in your area
HOW TO COMPOST?
If you google for “how to compost” the net will no doubt throw may different ways. Some websites recommend buying tumblers and special bins. I’d like to share a very simple method which works well for me, using resources I already have at home. Once you understand the broad concepts, you can choose your own containers, and experiment with your kitchen waste to suit the climate where you live and the kind of waste and volume of waste you wish to recycle. Be bold and get started! You’ll learn a lot along the way as I did, and I’m sure you’ll discover that it’s a lot simpler than it sounds.
Composting using container/flower pots and soil
Things you’ll need :
* Used flower pot (any material such as ceramic, terracotta or plastic)
* Soil (even degraded or old soil from your garden would do- if not you can get planting soil from the nursery)
* A lid ( I use old metal plates or lids as they are waterproof, but used cardboard, old thick polyethene sheets or old rags of carpet would do to cover the pots)
* A dish to keep below the pot for indoor composting
* Kitchen waste (which we’ll talk about in “What to compost and What not to compost” )
1. Take any used flower pot with holes at the bottom for drainage and aeration. Put a layer of coconut husk (or other material like cork) that decomposes more slowly at the bottom to prevent too much moisture coming out of the pot. Cover with a layer of soil about 5 cm thick.
2. Put all your kitchen waste for the day over this soil.
3. Cover the waste well with soil :
4. You can start all over again with another layer of waste the next day
5. And repeat by completely covering with another layer of soil. This will ensure there are minimal flies and smell. As you keep layering waste and soil alternately, you will have to stir the contents once or twice a week to ensure proper aeration.
6. Always keep the pot covered with a metal lid or thick cardboard or old rags of carpet. I tend to use metal because it’s waterproof and I can control the amount of moisture in the pot better when it’s exposed to sun and rain.
You may want to keep a series of pots and label them Pot 1, Pot 2, Pot 3 and Pot 4. As the first pot fills up, you can move on to the second, third and fourth. By the time the fourth is full, you’ll find that it has been 6-8 weeks in a tropical climate and the first pot is properly composted. Temperate climates may delay composting to about 3-6 months. Check the compost that is being made in the pots and remember to stir regularly once or twice a week.
Keep a dish under the pot to collect the excess moisture that will be released. This water is precious and can be used as fertiliser for plants. If you’re keeping the pot outdoors directly on the grass, the water will directly go to the soil and fertilise it.
Those with larger garden space can dig a hole and do the same process. Keeping the compost pit covered is a good idea to keep away pests and flies.
WHAT DOES COMPOSTING REQUIRE?
Air – Stir once or twice a week as required. This method is aerobic composting as it requires air. (The other method is anaerobic composting which is done in an airtight container). Lack of oxygen can lead to unpleasant smells. You may most likely get harmless fruit flies in the bin, which again will disappear when you cover the food waste with soil and mix and aerate well. Also, a mix of soft and hard materials in the pile will enable better air circulation.
Moisture – if the composting mixture is too wet, it will get smelly and become prone to fungus and slime. Add more browns like shredded paper or cardboard to absorb the excess moisture, which will also help to creat air pockets
Heat – The compost itself will generate heat. You may keep the pot indoors or outdoors. I get better results outdoors, as there’s more external heat which helps decompose matter faster.
It helps to chop or shred the materials into smaller pieces so the decomposition takes place faster. Materials which take longer to decompose should ideally be placed at the bottom of the pile and in moderate quantities.
A GOOD COMPOST?
* It smells good, like the smell of soil and rain
* It is crumbly without lumps. If lumpy, you can sieve the compost, and use the fine residue. The lumps can be thrown into the new compost pot as a starter mixture.
* It isn’t too moist and doesn’t have any fungus or moss. It isn’t too dry either.
HOW TO USE COMPOST?
Compost is best used as a top layer around plants. I use my compost once in 6-8 weeks when the pot is done, by applying a two inch layer on the soil bed. The compost can be used directly on a garden bed or for container plants. I’ve not explored if there’s an expiry date to the compost as my garden is always in need of new compost.
Browns provides the carbon required for the microbes to multiply. Less carbon would make the compost smelly (due to rapidly fermenting nitrogen into ammonia), overly moist and fungus prone.
* Dried leaves
* Chopped straw and small twigs
* Shredded Paper (non-glossy)
* Coffee Filter Paper
* Cardboard (without the use of commercial glues like formaldehyde)
* Shredded Pizza boxes (remove the cooked food residues on the boxes to the extent possible) * Dryer Lint
* Vacuum Cleaner Bag (contents should be sorted)
* Dryer Lint (provided most of the clothes are natural fabric)
* Used Kitchen Paper
* Kitchen and Toilet Paper cardboard rolls
* Cotton Wool (non- contaminated)
* Sawdust (non-chemically treated)
* Hair (not as clumps, very slow to decompose)
* Shredded cotton or wool (in small quantities)
Browns that can be composted but prefer to send for recycling
* Newspaper – The paper itself will decompose, but newspaper ink can be laden with heavy metals. So unless you are sure that the ink is non-toxic or soy based, it is better not to add to the compost, especially if you want it to be organic
* Cardboard with lot of print - such as cereal boxes are full of ink like newspapers. So make sure the inks are non-toxic. If in doubt, send for recycling
* Cotton, silk, woollen clothing – due to sheer volume, it’s better to send for recycling where it can be made reused or recycled into other items
What’s a good Greens to Brown ratio ?
The general rule of thumb is equal amounts of greens and browns should be put in the compost mixture. This will roughly enable a Carbon to Nitrogen ratio of 30:1 in the final compost which is recommended by most gardeners.
WHAT NOT TO COMPOST?
* Cooked foods (more on “What’s the matter with cooked foods?” below)
Non- Biodegradable and Hazardous Waste which should not be put in the compost, but sent for recycling or for careful disposal :
* Plastics of all kind – bags, bottles, cling film, wrappers
* Drink cartons (as they are layered with plastic or tin foil)
* Glass, Porcelein, Ceramic
* Glossy paper, magazines ( tend to have high chemical content in the inks and laminations)
* Cigarette butts
* Electrical items – bulbs, tube lights, batteries
* Oil waste – cooking oils, fats as in butter, margarine and fuel
* Wood ( is usually chemically treaded and will add heavy metal content to the soil)
What’s the matter with cooked food?
You may ask, doesn’t cooked food biodegrade? Yes it does but it is likely to cause problems in the compost. For one, it can smell really bad when the food starts decomposing, especially if you add meat or fish. It may also attract vermins and pests.
However, by using the right composting system (such as one that we will show in Part 2 of this blogpost) you should be able to compost cooked food as well. You may also use the above flower pots method, but you will have to use some kind of culture to accelerate the decomposition of cooked foods so one can avoid smells.
How to make or get accelerators or Biocultures?
Biocultures are not required with the above method, but with cooked foods it is necessary to accelerate the decomposition.
1. You could ask for “Bokashi” at the nursery. Bokashi is a bran containing yeast, fungi and bacteria which ferments cooked food, especially meat and fish in a few days time, without risking pests or flies. Here’s an E-how instruction showing how to make some at home.
2. Another Bio culture recipe that can be made at home is E-how’s How to make active compost microbes (using rice wash and milk to obtain lactobaccillus serum)
3. I have seen organic farmers in India use diluted cow dung (5% dilution in water) over their compost for a similar purpose.
I’ve yet to try these three methods mentioned above for cooked food. If you have had some success with composting cooked foods, do share them with us.
Hope to hear from you about your experiences, comments and queries on the topic. Wish you success in the journey of turning kitchen garbage into riches for your garden! Happy composting!
Credits: I learnt this method of composting from the article by Zhou Miao-Fei in the Singapore newletter “Lapis News ” July-September 2009 edition as translated from Mandarin into English by my friend, Ruyu Gan , a permaculturist.
For the many benefits of composting, here’s a very informative article from Permaculture Research Institute of Australia entitled, ” Compost Miracles “ which has found that “Compost microorganisms not only convert organic material into humus, but they also degrade toxic chemicals into simpler, benign, organic molecules. These chemicals include gasoline, diesel fuel, jet fuel, oil, grease, wood preservatives, PCBs, coal gasification wastes, refinery wastes, insecticides, herbicides, TNT, and other explosives.”
This is heartening to read, but would suggest avoiding this in your home compost. Nevertheless, a very insightful piece.
Read Excerpts from a wonderful book called “The Rodale Book of Composting ”