Sunday, January 6, 2013

Compost 101

Seems like it might be time to discuss this magical and mystical stuff "Compost"

I have been making and using the stuff for twenty years now, and it seems that there is a lot of mystique surrounding the making of compost. I have to wonder about that. Compost is pretty straightforward stuff. Maybe like learning to bake a good load of bread.

Let's start with a general list of ingredients. What is needed for success is a combination or mix of materials. Stuff rich in carbon, (not carharcol ), like dry plant material, leaves, straw and such. Then you need something for nitrogen, like fresh green plant materials, your kitchen scraps, coffee grounds, or manure.  What else? Water and time! The correct percentage of nitrogen to carbon is 25 to 30% nitrogen to 70 or 75% carbon.

I think the problems start when you have to guess the amounts of carbon vs nitrogen any given material contains . I try for a mix based on volume. One good tip off is the ordor level of the pile. A pile too rich in nitrogen gives off a rather putrid ordor for several weeks. A thick covering of leaves or straw can often right this problem.

Then comes the water element. In the southwest we have to drench the pile as we build it such that water pools up and really makes a muddy mess! Then we have to find a porous covering that retains moisture. I like to use carpet, old funky stuff that is being torn out and taken to the dump. In a wetter climate you might have to consider keeping water out of the pile, but microbes won't grow and live in a dry pile and without them your pile will be a flop!

Time? I allow 5 to 6 months for my pile to complete the digestion process of the microbes. In a warmer climate less time will be needed. Also if you start with smaller pieces of material the process is faster too. I think here in El Salvador a pile with manure and leaves will finish in 3 months. One farmer wants to make pile with some large stuff, banana plants, palm leaves, whole corn stalks. I guess this pile might take up to year to break down.

How do you know the pile is ready? Smell and looks. The pile will smell like rich sweet soil and large plant stems, leaves and such will be smaller, broken down.

I build piles by layering materials and watering each additional ingredient. For example, in Romero we started with a bottom layer of large dry stalky plant material, ie carbon. We watered that thoroughly. Next we spread a layer of manure, water, dry leaves, water, manure and so on. We covered the pile with a deep layer of dry leaves and then topped it off with a layer of banana leaves.

Other problems you may encounter are animal pests digging in your pile. I don't have much trouvé with this. A disturbed pile can just be reformed . If need be you will have to get creative with chicken wire, pallets and such.

I hope you are getting the idea that this a process, and one that you will certainly perfect with some trial and error. Until you find a good mix of materials to work with, I would suggest that you keep a record of what you use, the date you started the pile and what you think of the results.

Take your recycling efforts and your garden soil to the next level and build a compost pile in 2013!