12/4/11

Rebirth in the Garden: Composting at Karmê Chöling


By Aaron Delong

Why Do We Compost?

Managing fertility is a key component of long-term success in any garden. At Karmê Chöling, we rely on our compost as a primary source of achieving this goal. Compost acts as both a slow release fertilizer in our beds, as well as an organic matter builder in our soil. It also helps to reduce the waste stream produced by the center.



What Do We Compost?


The answer is: what have we got? Our compost is primarily composed of kitchen scraps (excluding meat, dairy, and some cooked foods), garden residues (plant debris), and cow manure (supplied by the farmer who hays our fields). Kitchen scraps and fresh plant debris are considered 'green' materials: materials rich in nitrogen. Older garden residues, such as woodier plant debris, straw and leaves, are considered 'brown' materials. Brown materials are rich in carbon. By striking the proper balance between brown materials and greens (about 20:1, carbon to nitrogen), we can create a compost pile that is both nutrient-rich and structurally sound. Cow manure is a vital component for us, intrinsically providing nearly the ideal balance of carbon and nitrogen, as well as being a good microbial activator in the pile.

Often, we chop up our compost ingredients before putting them in the pile. Sometimes we use a machete, sometimes we use a chipper-shredder machine. Chopping up materials reduces particle size and gives microbes and bacteria more access to their food source, speeding up the composting process.



How Do We Compost?

We build our piles in a layering method: a layer of brown materials is followed by a layer of greens, followed by a layer of manure. The sequence is then repeated. Our piles, when finished, are about ten feet by five feet by three. It is important for any pile being made to be sufficiently large enough to create an internal environment where bacteria and microbes can thrive. Three feet by three feet by three is considered a minimum requirement for this goal. At Karmê Chöling, we build bigger, hoping to attain internal temperatures between 130 and 150 degrees Fahrenheit. This ensures weed seeds will be killed and any potential diseases will be sterilized. Over 160 F, however, and harmful bacteria can enter the pile; bacteria that might negatively affect plants were the compost to be applied to a garden bed.

Turning the Pile

Compost happens, whether we tend the pile or not, but how fast the process occurs depends in large part on how much effort we put in to facilitating the decomposition process. Probably the hardest part of making compost is turning compost, but this action is critical towards speeding the breakdown of the organic materials in a pile. Turning introduces oxygen into the pile, allowing the bacteria inside to breathe and helping to elevate temperature. It also keeps the pile from turning towards anaerobic respiration in the absence of oxygen, a development that can slow down decomposition and lead to the buildup of toxic components in a pile. Often, when a pile 'stinks,’ it stinks of anaerobic respiration.

To turn our piles, we simply move the contents with a pitchfork from one place to another, hopefully nearby! We try and put the parts that were on the outside of the pile to the inside, and the parts that were on the bottom on top. This maintains an even rate of decomposition throughout the pile.

Water

In addition to size, oxygen, and carbon and nitrogen-rich materials, water is a crucial factor in the composting process. Too little water slows everything down, too much cuts off oxygen flow. The general guideline is that a compost pile should have the moisture content of a wrung out sponge. Occasionally, we will add water to a pile if it seems to dry. Often, we will cover our piles with cloths or tarps to prevent them from becoming too wet in the rain. We build our piles on old pallets, as well, to aid with drainage and aeration. Excessive moisture is one of our principal composting challenges at Karmê Chöling.

The Finished Product

The length of time it takes to create finished compost depends on time of year, time spent managing the pile, and quality of materials used. Generally, in peak season, we manage a finished pile in eight weeks. The original pile can be expected to diminish to half its original volume during the composting process. The finished compost itself should be a black, crumbly soil with a slightly greasy texture, high in organic matter content, holding a good supply of nutrients that will be gradually released over a long period of time.

We apply finished compost at a rate of about one wheelbarrow to every eighty square feet, lightly working the fertilizer into our garden beds with a rake. We can plant immediately thereafter.

Composting can be a lot of fun. There is an art to the process, a mixture of chemistry, alchemy, and common sense that changes with each pile we build. There is also a satisfaction in taking our 'waste' materials and using them as a foundation for future growth. In that sense, composting is a metaphor any meditator can relate with.