Farm Friday—Compost


Compost is the foundation of the Farm.  Beyond literally supporting life in and above our soil, compost also helped bring the Farm as an organization into existence!  In the 90s, a group of students who were frustrated with the College’s lack of commitment to sustainability began diverting food waste to what was formerly a gravel and trash pit in the Wash with the help of grounds and dining staff.  Before students began planting, they began composting.  And my personal journey here began with compost—I spent my first afternoon of volunteer hours in the fall of 2015 raking sycamore leaves to provide much-needed carbon to our growing compost pile.

At the Farm, we maintain thermophilic compost piles—right now we’ve got eight piles!  We layer food scraps (“greens,” higher nitrogen; no meat or dairy) and leaves or straw (“browns,” higher carbon).  To help support populations of aerobic bacteria and fungi that decompose the food waste, we turn the piles periodically for aeration.  This method works best for larger volumes of food waste, as the ideal pile size is a hefty cube.  Orin Martin at UC Santa Cruz wrote a wonderful guide for this method of composting, which we generally follow at our farm.  Once our compost is finished, we sift it into wheelbarrows and use it to amend our beds before planting.

Three bin systems are great for backyard composters because they work for smaller volumes and require a bit less manual labor; however, they do require a bit of construction to establish.  Once you build the three bins with wood and wire netting, you can start adding food waste and dried leaves!  You only ever add new material to the first bin; once it starts to decompose and heat up, you transfer material to the second bin to mix and aerate; the third bin is for finished compost.  Here is a detailed guide of how to add to and maintain your compost system.

Vermicompost systems can be fun if you have limited outdoor space, as they are small, odor-free, and can thrive indoors.  Unlike the previous methods, worms are the primary decomposers in vermicompost systems.  Once you create a bin for them (or buy a system), you feed them food scraps and they leave behind nutrient-rich castings (informally referred to as “black gold”).  Red wrigglers, not earthworms, thrive in these systems, so unless you have a compost or manure pile in your yard, you can buy worms.  While most of the food waste that comes to the Farm is composted in piles, we do use some of it to feed the worms in our worm bin!

Soil is living, so it’s important to help it stay healthy if you plan on using to grow produce and extract nutrients!