Small scale compost systems
Small scale compost systems – bin style, slow composting.
The process of turning organic matter into compost can seem like magic, though it’s really quite simple with a few pointers kept in mind. There are thousands of types of soil organisms smaller than worms. Keeping these guys alive is what makes all the difference. Even slaters have their place when included in compost.
Large scale composting is not an easy thing to manage, requiring physical effort to turn the heaps, whilst the input materials (leaf mold and other soft leafy stuff) are not always easy to gather for free in Australia where native plant leaves are often waxy and don’t break down readily. Various kinds of straw can be used instead or your own home-grown mulch and biomass. We have bannah grass, which is kind of a hassle and a fire danger where we have it, too close to the front door, but the leaves or mulch from it are ideal for composting.
This is where small-scale systems such as the various bins that are available are great. The larger bins seem superior due to the heat buffering quality of larger amounts of matter in the bin, where some of the smaller, more narrow bins can be unsuccessful due to sudden temperature variations or rapid drying out. Keeping rodents out by placing mesh underneath is also a good idea when you first place the bin in the garden.
We’ve been using tyre piles for a few years now, which seem to work well given the right position and a well- fitting top or lid. The lid keeps a large amount of water in the bins by returning condensation into the contents. Finding a large enough lid can be a bit tricky, we have used large plant trays or even a large pot to put in the top hole of the type pile to stop rodents entering.
Improvisation is okay, just so long as flies and rodents can be kept out. You’ll probably want two of the same systems so that when one fills up, it can be properly rested and finished off, while the second bin is then started. You may even find you need more. They can quickly fill up with a bit of pruning or weeding. These bins can create high quality compost if managed correctly.
These systems will attract worms, so certain points need to be kept in mind when placing the bin. These include the amount of shade and sun. Too much shade and it will be too cold, too much sun and the worms may leave or dry out. Winter and summer sun angles will vary depending on your latitude.; the ideal winter spot could become too toasty in high summer. Make sure you know where the sun will be in summer so you don’t cook your worms.
The bin/pile should be fairly close to the front or back door so it is easily attended to. It can be difficult taking a bucket full of scraps out the back door, so you don’t want to lug it too far. It may also be handy to plant heavy feeders (such as banana, pawpaw or rhubarb) near the bin to use up any tasty nutrients that may leach through, though not where they might get splashed with yucky sink water or compost bucket water..
THE MIX – WHAT’S IN IT?
On a very basic level you need carbon materials and nitrogen materials. Another way of looking at this is brown or dried things (carbon) and green or wet things (nitrogen). Carbon is more stable and denser where nitrogen is quickly broken down into dark, gooey, wet stuff.
There is a particular ratio which is often misunderstood, nobody ever seeming to be able to explain what it really means. The ratio of carbon to nitrogen is 25-30 to 1.
Generally you want more dry/brown/carbon material than wet/green/nitrogen.
Carbonaceous things tend to be more dense so may not look like there’s much of it. Too much carbon will cause the compost to remain dry and not break down, whereas too much nitrogen can make the whole thing anaerobic (no oxygen), slimy and smelly.
The two kinds of materials should be mixed or put on in layers, rather than, say putting a huge pile of grass clippings in all at once, you might put it in layers with some dry straw or old paper products to keep the ratio right and to maintain air flow through the grass clippings and other green bits.
I tend to judge by the look and smell of the pile when it get’s looked at each time (like when the next bucket of goop goes on top), whether anything green or brown needs adding for balancing. Depending on how good (or bad) your diet is there may not be very much actual food going into the bin for the worms and other soil-life to consume. You may think you have a balanced diet, but certain things could still be missing from the worms diet, and will not appear from nowhere.
It is a good idea to add a variety of manures and minerals to the compost too, to help decomposition and build soil health. Dolomite lime is good to sprinkle in when it’s all too gooey and wet. Worms also like a bit of cornmeal from time to time
The amount of water is important to keep life alive too. A few waters a week is probably okay. The top doesn’t want to look too dry. Moisture produces a humidity which soil life loves. These few tips will hopefully help you create life in y