One of the ongoing garden projects is the compost system. The aim is to minimise the use of chemical fertilisers by feeding the soil with organic matter. The principle is to not only provide nutrients for the immediate vegetable crops but to improve the soil structure for future crops.
The soil in my garden has a high clay content. This results in poor drainage with waterlogged soil in winter and a hard dry soil in summer. The compost adds organic material that forms humus to fill in the spaces between the soil particles.
The humus separates the soil particles and this has two benefits. It improves drainage by allowing space for water and air to pass between the particles. The humus also holds some moisture plant roots.use this in dry summer periods.
A soil with good structure is friable. The soil is crumbly to the touch but with enough moisture to retain more structure than the fine dust of dry clay soil.
Making Compost
The basic composting method is to pile organic material in heap and wait for it to decompose, but this is rather slow.
One of my plastic compost bins
There are a variety of ways to speed up the process. Plastic compost bins keep the heat from the decomposition process in the compost bin, and the bin also collects and transfer any heat from direct sunlight into the compost. All this extra heat speeds up the decomposition process and helps kill any weed seeds that end up in the compost.
Decomposition Process
There are two agencies for the composting process. Natural decomposition aided by bacteria breaks down the material and then as the pile cools, earthworms enter the pile and eat the material producing worm casts.
According to the instructions on the bins, and confirmed by popular knowledge, is adding lime to the compost reduces the acidity inside the compost and this benefits the worms and the natural decomposition process.
The bin makers also recommend adding blood and bone to feed the process of breaking down the leafy fibrous material.
Compost Needs to Breathe
Adding different types of organic material in layers helps aerate the mixture. In larger operations rotating bins or large machines turn the compost piles breaking up any layers that form. Moist food scraps often form a sticky mass. While the dryer leafy material tends to form a preserved layer, as in dried food. The ideal is to get a mixture of the two. As well as redistributing the moisture content it also allows air into the mixture for the worms and bacteria.
To preserve food it is usually sealed in airtight containers and or kept cool in the fridge to slow the natural decomposition processes. In the compost pile the exact opposite is true, we want to get it hot and have plenty of fresh air in the mixture to speed up the process.
For our simple bins I use a hand tool called a Compost Mate that looks like a large corkscrew. It screws it into the compost and when it is lifted the inside of the screw thread is full of material from the lower part of the pile. This is then spread on the top of the pile. This process makes a hole for air in the bottom of the pile, as well as mixing different layers on the top.
This screws down into a compost heap to aerate and it and distribute material
Using the Compost Mate depends on the content and how the process is going. I usually wait for a while to let the compost settle and generate some heat first. Then it depends on what you bring up with the tool, if it is too compacted it may require more, or just an occasional stirring if it is going well. Adding a bit of extra lime and blood and bone will helps with their distribution.
What Goes In
Anything that lived can go into these things, that is any organic matter. This does depend on the area and design of your bin. My bins have secure lids that do not allow flies or vermin in to the compost. This means I can put in meat scraps. Burrowing animals could be problem but so far I have not had a problem.in my garden. This is an important consideration when choosing a compost system for your locality.
Do not put too much of the one thing in the compost bin at once as too many vegetables make it wet and gluey. Adding leafy stalks helps separate wet vegetable matter. Chopping up large stalks and leaves avoids making it too solid and dry.
All our kitchen scraps and garden waste go into our compost bin. The soil in the garden beds after a few years is much better than the surrounding soil that has just been left as lawn.
