Aerobic Vegetable Composting 1

After the disheartening math on nitrate production from liquid mammal waste, I decided to do a regular compost based on food scraps.  Whether this makes sense or not, I avoided garden clippings in this run because the measured goal is nitrate production. Any fertilizer remaining on the garden clippings would skew the results, showing a false success.

With that in mind, I am composting things that humans would eat, not simply vegetation. I expect I'll do a vegetation one as well, and perhaps both varieties supplemented with other materials, but for now I'm just taking the simple route.

Tools and Materials

Organic matter

I got the material from several local chain restaurants. I walked in, asked to speak with the manager, and asked if I could get a day's worth of produce scraps from their counter/prep area. Some did prep in the morning, and asked me to come back the next day. Others gathered their scraps all day and asked if I could come back later in the evening. Everyone was quite willing to help.

Here's what I ended up with:

• Lettuce
• Mix of lettuce & other vegetable matter
• Meat scraps

The Composter

I just used a rolling trash bin I bought at the hardware store. I cut holes in the sides to allow aeration. I considered buying a "real" composter with a horizontally mounted cylindrical drum and a crank on the side, but for my first run I figured something less sophisticated would do. The bottom of the bin was watertight, to prevent solubles from escaping during the composting process.

Process

The pile

Lettuce, cabbage, tomato, and other vegetable scraps have a C:N of about 12, so in order to get out to 20 or 25, I needed some carbon added. I bought a bale of straw from a local pet supply, weighed out Nkg and added it in in layers with the vegetable matter. This was a single-batch process. Everything was added at the same time.

The Weather

August in southern California is sunny, not particularly humid nor arid, and stayed in the 70s and 80s for the entire period.

Results

Catastrophic failure, experiment terminated early. Apparently there was too much animal protein in the mix. By day six the rotting smell was overwhelming and I terminated it. I shall fall back and consider other alternatives, certainly including no animal matter in the next incarnation.