Photo by Kyle Ellefson on Unsplash
Let's say we want to setup a compost pile and make compost quickly. To accomplish this we need a large and quickly growing population of microorganisms. The rapid increase in microbe population and their metabolic processes create heat in (thermophilic) composting. The ideal carbon to nitrogen ratio (C:N) is approximately 30 parts carbon to 1 part nitrogen (30:1)
So how do we get a an assortment of mixed organic waste to approximately 30:1 C:N?
First we need a unit of measure we can define as a "part" (measures are by volume). So for a small pile it might be a 20 liter bucket, for a larger pile maybe a loader bucket, it doesn't matter as long as what we use is consistent.
Next we should define what is usually called "brown" material (usually dead and dry) it has a C:N with the C being larger than 30.
Conversely a "green" material is usually still wet and fresh with a C:N where the C is less than 30
To balance a pile at 30:1 we need both.
Whatever your waste product to compost you can almost always find a C:N ratio online using your favorite search engine. I usually look up several and take an average as these can differ a bit depending on the state of decomposition prior to adding them to your pile.
The easiest way to show how calculations are done is to use an example, for this we'll use autumn leaves (brown)and grass clippings(green). These are 2 frequently available waste products. I find the average C:N of leaves is about 70:1 and of fresh grass clippings 17:1
We are interested in the carbon side of the ratio and usually start with 2 parts of a "brown" to one part of a "green"
1 part leaves at 70:1 we use 70
2 parts grass clippings we use the 17+17=34
add the C's together (70+34= 104) Then divide by the total number of parts (3 in this case)
"close enough" to make a good compost pile- just thoroughly mix the ingredients, dampen them to a damp sponge moisture level and pile them up. Very soon our pile will become hot. Monitor temperature a couple of times/day you want the temperature to rise above 57 C but not go above 65 C. If your pile approaches 65 you should turn the pile and add a few more leaves, dampen the pile again if needed. If your pile won't reach 57 C mix in a little more grass clippings, turn the pile and moisten if needed. If the pile begins to cool below 57 C then add nothing, turn the pile and let it heat again. Turning is necessary to keep oxygen in the center of the pile for our microbes. After a couple of weeks the pile should have very little material that's recognizable and it should look like soil. At this point turning can be reduced to 1x a week while the compost cures ab additional 14 days or more before adding it to your garden.
Your ratio is good. When I make my recipe by buckets (Backhoe) I add Biochar 5:1:1 which has done well for me. Season is coming on I will post as the season grows on. See you in the future.
Excellent, I look forward to it and I'll follow you to see it
Congratulations @thebluewormbim! You have completed some achievement on Steemit and have been rewarded with new badge(s) :
Click on any badge to view your own Board of Honor on SteemitBoard.
For more information about SteemitBoard, click here
If you no longer want to receive notifications, reply to this comment with the word
STOPI would add that C:N ratio is also important in a worm bin not just compost pile. Can you elaborate on this ?
Thank you for contributing your knowledge to help others! This post has been added to the Sotall.org Directory of Self Sufficiency & Survival posts. One of our goals is to provide access to the knowledge of our fellow Steamians, that will still be seen, long after the 7 day period is passed. If you write any future articles with instructions on how to do any tasks related to a homestead or survival, to ensure they are added to the directory, please submit them. They will be added as soon as possible.
How can I figure out the ratio when using all sorts of different kitchen scraps? An also, do all dry leaves have the same amount of Carbon?
Thank you for this valuable info.
It isn’t an exact science but following these guidelines will get you close enough to be successful