I find that in any situation I never have enough compost. Purchasing quality compost can be expensive on a shoestring budget. It is the quintessential soil additive helping hold water and nutrients in the soil while protecting the plant from a wide variety of problems, from providing nutrients, to helping prevent water loss.  Every year I try to add compost to the soil of all of my perennials.

So, what is compost?   Compost is a mixture of fully decomposed organic matter that has a dark, rich coloring. Good compost makes it difficult to see what the parent material was; everything in the compost has been broken down by microbes, insects and worms. Yard waste, food scraps and even fecal matter can be composted safely if given the right circumstances. It is our job as gardeners to provide the right environment to facilitate decomposition and sterilization of potential pathogens.
  
Keeping the right ratios of the types of ingredients is really important to keeping happy, healthy and pleasant smelling compost. The aroma of well decomposed and finished compost is one of my favorite smells---it is the smell of earth, musty, almost chocolate like. I have also smelled compost that was wretchedly foul. It had to be hands down the worst smells I have ever let come in contact with my olfactory organs--rotten eggs would smell much better.  I thought that it was interesting that it was from a vegan household all the nasty odors were coming from fruits and vegetables. I was there to remove some trees that were threatening their house and we happened to fall a log onto the corner of the compost pile, when out wafted the previously mentioned malodorous stench.

The problem was that there was too much water and nitrogen in the pile, so that the slop fermented anaerobically (without the presence of oxygen) producing all sorts of funky aromatic nitrogen and sulfur compounds.  More dry matter and carbon is needed to keep a healthy balance. One must keep the compost wet enough to continue composting, but not so wet that it replaces the oxygen in the compost system. The pile should feel damp, but water should not come out when the organic matter is squeezed.

The carbon to nitrogen ratio is a really important factor to keeping the compost smelling pleasant.  The ideal ratio is about 30 parts carbon to one part nitrogen.   Most dry material such as wood chips has about 40:1 while most sloppy  wet things have around 10:1.   If you want to know the C:N ratio for a variety of commonly composted items, please see the end of this article. Finding enough carbon can be hard to accomplish. Attaining sawdust can be difficult unless you know a carpenter, but newspaper composts wonderfully as do paper egg cartons, and most households have plenty lying around. Just rip it into shreds and add it to the compost bucket in the house as needed, to prevent the juices from collecting on the bottom of the compost bucket.

Not only is moisture content and C:N ratio crucial to a successful compost pile, having enough air is what allows the midden heap to compost.  The organisms that break the compost down require oxygen to do their work. Just as flavors blend in a pot of soup more quickly when you stir it often, the more the pile is turned the faster the pile will break down. The best method I have found is to turn the pile every two to five weeks, which depends on the gardener’s time and priorities.  Some people turn it every few days and can get finished compost in about 2 months. 

Compost is a delicate thing to keep in optimal balance.   If there is not enough water, nothing happens. If there is too much water, it rots.   If there is not enough carbon, it stinks like ammonia, and if there is too much it will take forever to break down.  Humans have devised a broad spectrum of ways to speed up the composting process, and ultimately it is not that difficult to compost most organic matter.  As long as the proportions of carbon and nitrogen, and water and oxygen are correct, the pile takes care of itself.

Approximations of Carbon Nitrogen ratio’s of common compostables
Cow manure 30:1
Fallen leaves 40:1
Fresh grass clippings 15:1
Fresh Vegetable Wastes 10-15:1
Fresh weeds 10:1
Sawdust 150-200:1
Seaweed 10:1
Straw 50:1

Works consulted
Jenkins Joseph  The Humanure Handbook: A Guide to Composting Human Manure
Jeavons, John The Sustainable Vegetable Garden: A backyard guide to healthy Soil and Higher Yields
Mollison, Bill Permaculutre: A  Designers’ Manual Bill

http://www.organicgardening.com/feature/0,7518,s1-5-21-112,00.html
Http://www.ranchomondo.com /compost/cnratio.htm

Last update: November 13, 2009
12:02 pm

Published in : Articles, Green Tech

Keywords : Compost, smell, Carbon, nitrogen, ratio, finished, buffer, sloppy, denitofacation,

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