Research Project About Speeding Up Composting
Question
December 23, 2018
We are working on a research project (undergraduate) in a program at University of British Columbia where we are trying to measure the rate of compost depending on different carbon to nitrogen ratios. Our research question is: how does changing the amount of carbon in compost affect the rate of compost? We know the ideal ratio is a carbon to nitrogen ratio of around 25:1.
We will test above and below this number to see if it is true.We would like to build compost bins in order to measure the rate of compost of certain materials. We would like to explore if adding a certain amount of a material will help to increase the rate of compost. We will measure the rate of compost by measuring the mass and temperature of the compost on a daily basis, using the criteria of compost mass reduction to 2/5 of its original weight and when temperature lowers below 20 degrees Celsius above ambient temperature. We will graph this daily trend to ensure lots of data points. We will be monitoring temperature, light, pH, and moisture on a daily basis and the compost bins will be kept indoors at around 20 degrees celsius. Due to ethics concerns, we are not allowed to use animals or live organisms as part of our experiment.
We are wondering if you have any suggestions on what materials would be ideal to use in very small amounts (about a kilogram) in order for a speedy composting process, as well as any other major influencing factors that we should take into account. Any other tips for speedy compost will also be greatly appreciated!
Answer(s)
Answer by JZ: Great that you are considering this vital aspect of decomposition in the composting process. I think what you would be considering too is how ratio variations would impact on the rate of decomposition. I think you might consider this experiment as also an exercise in manipulating microbial nutrition.
What composting process you intend to employ would influence microbial activity, therefore the decomposition rate: Hot process or Cold process. Pardon if I am mistaken, but you did not mention your chosen process in your mail.
Some organics which may be easy to get in the winter months in BC might be:
a. Shredded brown leaves and / or shredded paper products - browns / carbon
b. Coffee grounds - greens / nitrogen. Area coffee shops, UBC cafeteria might save them for you.
You could vary these by weight in your test setups.
The variables which would impact decomposition:
a. C:N ratio of mix
b. air content/ flow thru the set up - bulk density of the mass. How will air flow be managed ?
c. moisture content of the mass / mix
d. temperature of the mass / mix
e. pH of the “ “ "
f. particle size of organic ingredients added - not mentioned in your mail
g. Chosen composting process - hot or cold ? This choice will impact on the time for decomposition to proceed and be completed.
h. Management of the setup: static or actively turned & churned
h. Will beneficial insects be involved ?
i. Will microbial inoculants be added to the setup ?
j. What criteria will you use to determine that the decomposition process is complete?
This is what comes to mind. Excellent project. Please keep us informed as you move along. All the best.