Compost nutrition: the secret to successful composting
When it comes to successful composting, being mindful of what you put in is important. We can think of it like needing a balanced diet; the right combo of nutrition is best. That is, gather the right sorts of wastes to make composites that have nutritional balance.
Unbalanced waste composites are typically the cause of composting difficulties like slow breakdown of wastes, compost fly infestation and odours.
Fortunately, it's simpler than it might sound: there are only two broad categories that we need to keep in balance.
Compostable waste categories
Compostable wastes are classified as either C or N types according to composting convention.
C wastes take longer to compost while N types compost too fast with odours. When C and N wastes are combined correctly to make a balanced composite, both are used at similar rates and the result is a fast breakdown of waste with no bad smells.
Examples of each type of wastes are below:
| C-ultra | C-rich | N-rich | N-ultra |
|---|---|---|---|
| Wood chips, sawdust, cardboard | Paper, straw, fresh garden waste | Vegetable & fruit scraps, coffee ground, leafy weeds & cut grass | Poultry manure, meat scraps, urine |
It is generally easier to use wastes in the -rich sub-category to create a balanced composite. Wastes in the -ultra sub-category can be included but in limited quantities.
Balanced waste composite
In practice, you generally get the bulk of your home compost from either your garden or your kitchen. A garden composite has an abundance of (C type) garden wastes, while a kitchen composite contains abundant (N type) kitchen scraps. Dissimilar wastes are required to balance the composites, namely:
Balance garden wastes with N wastes, e.g. leafy weeds, cut lawn and coffee grounds. Use kitchen waste selectively as these N types can cause smell problems.
Balance kitchen scraps with C wastes such as paper and tip prunings. Use C-ultra soiled cardboard (e.g. bottom half of a pizza box) sparingly in thin strips.
Your compost equipment also determines the types of wastes you can use and the relative proportion of C and N wastes in your composite.
You can compost garden composites successfully with tumblers and open-ended compost bins. An advanced system like Bioverter can compost composites containing kitchen scraps as the main component. Read more about it here.