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Feedstock Sources


September 17, 2018

My daughter would like to build a hot compost pile for a science fair project.  A hot compost pile needs to be at least 1 cu yard.  As you know, that requires quite a bit of feed stock!  Is there a place in Albuquerque where we can buy or obtain carbon and nitrogen rich feed stock to build our compost pile?  Our zip code is 87111.


Answer by JZ: I will offer some of my ideas.  Other colleagues may also respond.

Many Starbuck locations give away spent coffee grounds.- nitrogen

The squeezed juice bars in the city used to save up juicer left overs(nitrogen) if you call and ask. Squeezed Juice Bar.

Soon we will have an abundance of brown leaves - browns, which may be stored for future use.

Paper products (browns) are abundant, used napkins, cardboard,  paper towels - the school may use them in rest rooms.

You may dry and /or freeze kitchen scraps., then add at a later time.   Prunings from you garden may also be saved then added.

Hot composting synopsis in Composting in the Desert.

She could do a small hot setup as a demo, but most likely a small volume will not hold in the heat, but it would heat up with proper C:N mix.

This what comes to mind.    Hopefully helpful.

Answer by JH: Missy, you may receive a number of replies from our group. Here’s mine...
I don’t know where you would buy such items but that doesn’t seem necessary. I presume a sufficient supply could be collected in your neighborhood - ie dead leaves (C), grass clippings, garden debris, and kitchen scraps (N); local coffee shops - coffee grounds (N); neighborhood landscapers - grass clippings (N). Additionally if you have access to farm animal bedding (C) or manures (N) that could supply all that is needed. Just be sure if you are using manure that the animal wasn’t wormed within the past 3 months or otherwise your daughter will want to note that as a precaution, not to mention avoidance of feedstock containing herbicides. Local parks are a good source for bulking material such as pine cones and twigs.

I’m not sure how your daughter intends to manage this pile for the duration of the fair and I imagine you’ll help her think this through but if she is using an airtight container or any container that will inhibit good airflow, she’ll want to be vigilant about mixing the pile to avoid it going anaerobic and creating an objectionable odor.

Response from Questioner: These are all great ideas.  Someone will maintain it after science fair.  Probably me!  I'm hoping she can develop a Phase II to from it.  Right now, she's working to convert the thermal energy to mechanical energy via a Stirling engine and then converting the mechanical energy to electrical energy.  That last part still needs to be worked out.  But a Phase II to this project could be manipulating the operating parameters and studying the effects on efficiencies.  But first we need to build the compost pile!  Thanks again

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