LBHS: Aerobic Composting

Workshop Series

Hello again, the following post details my progress working with students in the gardening elective at Luther Burbank High School in Sacramento. As a result, this particular post will become augmented as I develop more curriculum for the students. 

The school itself has an amazing infrastructure complete with 20 raised beds, a greenhouse, shade house, animal stalls and a barn which houses a tractor! Unfortunately, after the school lost funding for its gardening program 7 years ago many of these resources have been neglected. The tractor now gathers dust, the barn is used for storage, and animals are no longer present on campus. However, due to the superhuman efforts of teacher, Aaron Mcclatchy, and Health Corps Coordinator, Isa Del Signore Dresser, I have been given the opportunity to teach the students some skills they can use to revive their gardenscape (picture below).

Aerobic Composting Building and Scavenger Hunt

The aerobic composting workshop takes about 20 minutes including 10 minutes of discussion and 10 minutes of activity.

Workshop goals:

Teach students what compost is and how to make it. Teach students why composting is important.

Required materials:

- spade/pitchfork

- food scraps

- leaves, grass clippings, yard waste

- hose 

- staging area for compost pile

After an initial discussion where I asked the kids some simple questions, "What is compost?", "Why is composting important?", I realized that none of the students felt comfortable with the what or whys of composting. As a result I gave a brief talk about soil and plant nutrients to supplement the compost talk.

Background information:

Compost is decomposed plant matter. Composting is important because it replaces nutrients that were taken from the soil. Just like humans need certain vitamins and foods to stay healthy, plants need certain nutrients found in compost in order to grow and produce fruit. Plants gather nutrients from the soil and store those nutrients in their leaves, stems, flowers, and especially fruits. In conventional agriculture, we harvest the parts of the plant that have the highest concentrations of nutrients and ship them hundreds of miles away from where they were grown in order to feed people. As a result, those nutrients that were once in the soil are now also hundreds of miles away and over time the soil will become depleted of vitamins that plants need. By composting, we return the nutrients that we took from the soil. Thus, composting is important because it ensures that the land will continue to support us. 

How to make compost:

We make compost by layering high nutrient food waste with low nutrient yard waste and adding water. By sandwiching a layer of food waste in between two layers of yard waste we are creating an environment that is suitable for the decomposing microbes to breakdown the plant matter into soil. All we have to do is add water until the waste pile is about as wet as a wrung out sponge. 

Activity Section:

Each student is encouraged to help build the compost pile by digging a hole in the yard waste and placing a shovel full of food waste into the hole. 

The next part of the activity encourages students to go on a scavenger hunt in the pile and identify the following items:

- a piece of high nutrient waste

- a piece of low nutrient waste

- find something that doesn't belong in the pile

After the activity section of the workshop, one student is asked to water the pile as the others reflect on the pieces of waste they gathered from the pile. The students should be able to justify what they found as fitting into one of the three categories mentioned above.