Carbon to Nitrogen Ratio

Each month, we send a sample of our compost to the US Composting Council. The Carbon-to-Nitrogen ratio is one of the properties that is tested.

The Carbon-to-Nitrogen ratio is an important factor in the quality of compost. Composting microorganisms require the correct proportion of Carbon for energy and Nitrogen for protein production.

All organic matter is made up of substantial amounts of Carbon combined with lesser amounts of Nitrogen. The course of decomposition or ogranic matter is affected by the presence of these two elements. The balance of Carbon and Nitrogen is called the Carbon to Nitrogen ratio (C:N ratio). If a material has a C:N ratio of 25:1, that means there is 25 times as much Carbon as Nitrogen.

Decomposition of organic matter is done by living organisms that require Carbon for energy and require Nitrogen for protein production and building cell structure. The best compost has a C:N ratio around 25 to 30 parts Carbon to 1 part Nitrogen and is dark, rich colored, soft, and easily malleable in your hand.

If there is too much Carbon on the C:N ratio is too high, decomposition slows down. This is because there is not sufficient nitrogen for optimal growth of the microbial populations, so the compost won't get hot and it will decompose at a slower rate. If the C:N ratio is too low, you will have a smelly compost pile because the microorganisms can't use all the nitrogen and the excess is lost in the form of smelly ammonia gas.

We send a sample of our compost to the US Composting Council under the STA program and each month, properties such as the C:N ratio are tested. You can be assured that when buying compost from Aguinaga Green, you are receiving the very best quality.