I’d give anyone a pat on the back that is composting their food scraps as apposed to throwing them in a plastic trash bag. But for those of us who want to take a step further and use our compost to produce valuable fruits and vegetables, there are a few things that you need to know first. Healthy compost that breaks down quickly is more than just a pile scraps. There are certain levels of Nitrogen and Carbon that create the perfect pile.
The Carbon to Nitrogen Ratio
Every compost pile needs a balance of materials that contain Carbon and Nitrogen. How can you tell which is which? Materials with high amounts of Carbon would be brown in color and drier. Materials that are wet and green would contain more amounts of Nitrogen. Generally speaking, a 30 to 1 Carbon Nitrogen ratio is ideal. This does not mean your compost pile has 30 parts carbon to one part nitrogen. This is referring to the amount of carbon and nitrogen that are in the specific compostable material you have added.
- BROWN– Carbon: Nitrogen is greater than 30:1
- Dry materials 40-50% carbon.
- GREEN– Carbon : Nitrogen is less than than 30:1
- Wet Materials 10-20% carbon.
Here is a list of common compostables and their C:N.
To get a general idea of the Carbon to Nitrogen ratios you have in your compost pile, add up the number of carbon in each item divided by the number of items you have. Example: Leaves 60 + Veggies 25 + Food Waste 20 = 105 Carbon. 105 divided by 3 = 35. This would be a decent composting mixture because 35 is close to the 30:1 ratio.
H2O and O2
In addition to the Nitrogen and Carbon ratio, water and oxygen need to be present. You can aerate your compost by mixing the compost up with a shovel. It is important to keep moisture for decomposers to break down the matter and do their job. The sun can allow for faster decomposition but only if the compost pile has enough moisture. Dry compost will slow down decomposition. Water your compost as needed, just like you would do for your plants. If there are days were there is too much sun you can put a tarp over your pile to help retain moisture.
Let’s take a closer look…
Microscopic organisms, insects, worms, snails, and fungi are all decomposing the organic material. As they break down this material, they release carbon dioxide and heat. This is why ideal temperatures for a compost pile are around 90-140°F… pretty toasty. However, temperatures higher than this can kill off not only pathogens but beneficial bacteria in your compost as well. When you go to plant your garden, if the temperatures exceed this range it is usually because you have too much Nitrogen in your compost and this could put your plants in danger of disease. Temperatures lower than 90°F may have too much Carbon. Low temperatures allow for slower decomposition rates and you will just have organic material, not compost.
In terms of parts, generally speaking you can have two parts green to one part brown in your compost. So for every two buckets of food scraps I dump in my compost I want to make sure I add one bucket of paper or leaves on top and repeat the process. Check out http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html for more information.
Thanks for reading. And as always, happy planting!