Making Compost = Creating Fertile Soil

19 Jan 2018

Many friends that come visiting the farm asks us how come the soil in our gardens looks so dark and full of life after being on the land for such short time. Well, the answer is that we’re quite diligent at making our own compost.

The style we’ve been using so far is the „Berkley method for hot compost“. There’s a few technicalities to this technique but it’s in general very simple and after a few tries quite easy to master. It does require some physical work and attention if you’d like the result to be fast.

It goes as following:

The golden rule is the following: everything that has lived, can live again. That means that anything that is (was) a plant or animal can be composted and will be broken down again.

You should see the materials you put in divided into 2 groups: carbon rich materials (or brown matter), and nitrogen rich materials (or green matter).

Carbon rich materials would include all kinds of dry plants such as hay, straw dry leaves and dry grass cutting. Also small wood particles such as saw dust, wood chips, very small branches and even paper or cardboard (without any colours on them as they too will become food). In general the more woody the material you put in, the longer it will take to brake down.

Nitrogen rich materials include any plant that are still green, veggie scraps from the kitchen and any kind of manure, urine and dead animal (of reasonable size). Now you should be careful with the kind of manure that you use in the compost if you want to use it in your veggie garden. Humanure for instance can contain viruses that could survive the hot compost breakdown and be contagious, therefore always choose manure that you know it’s free of medicine and from animals that you know are fed organically.  

In order for the break down to happen as efficiently and quickly as possible there’s a certain ratio that you should have into account. The compost pile will break down the best if there are 30 parts of carbon to 1 part of nitrogen, also a ratio of 30/1. There are tables that can tell you what the ratio of different materials is, giving you an idea of how much of each thing to add to the pile. We can tell you from experience that there’s no need to be too geeky about this one. It just give you an idea and a “feeling“ of how much to put in. It will take you probably about 3 tries to really master the amounts of things you put in depending of what you have available.

The way to build up the pile is to start by putting a square layer of about 7-10 cm high with strong chunky corners. The area of the square should not be less than a square meter! After that, add a 5 cm of green matter on to of the previous layer. Repeat this layering (one layer of green matter followed by one of brown matter) successively until you reach at least one meter in higth! This is a very important requirement for this technique. A m2 pile is the smallest size you can have for this pile, therefore is necessary that you safe enough material to be able to build the whole pile at once.

As you are building the pile, bring a hose and water every few layers making sure that the pile is quite wet. Much of the water will run through but this is ok. Once the pile is done, water again and cover with a big old rag, carpet or plastic fabric to avoid evaporation. When this is done, walk away and come back after 4 days.

Prepare to be amazed!, as you remove the cover you should already feel the heat coming from the pile, resulting of the breakdown that the bacterias have been caring the last days. Take a pitch fork and start taking away parts of the pile and rebuilding it right next to it again. Don’t mind the layers anymore, just try to rebuild it as evenly as possible making sure that the corners are quite chunky and strong to avoid it to collapse. The reason for turning (rebuilding) the pile is to add oxygen to the pile as the bacterias need it and water in order to be able to digest (just like us). Add water to the pile but don’t exaggerate, it should be moist but not wet. Remember to cover again when done turning and watering.

Keep on turning the pile every second day until the pile doesn’t heat anymore and it takes a black colour and a, earthy forest smell. If the ratio is right and the amount of water and air is right the pile should be ready after 18 days! It will probably take a bit longer the first few times until you learn how your materials break down and optimise the amount of water/veggie scraps/straw, etc. that you put in the pile.

If the pile at some point is starting to smell a bit sour and rotten, it’s because there’s too much green matter in the pile and you need to add more carbon. A bit of sawdust normally solves the problem for me. It can also be because there’s too little air or too much water. Grab a handful of compost and squeeze it lightly, only one drop of water should run down, not more. If too wet, turn the compost and leave it uncovered for a day or two.

If the pile smells kind of sweet and woody, the process didn't really start, it needs more green matter. As I said before, it will take a few tries to perfection. It’s not different from baking a cake, with a bit of practice everyone can make a good one.

Once the pile is done, apply it to your garden or sift it and use it for potting mix (combined with sand and coconut fibre for ex.). The particles of a well done compost pile can last in the soil for up until 14 years! Your plants will be happy and your veggies very delicious.