Compiled by Casey Williams and the New Mexico Compost Coalition
This article is intended to give an overview of different styles of composting that work well in the high desert environment of New Mexico. We hope it will assist in deciding why you may want to use one composting method over another in a given situation.
Before delving into the styles outlined in this document, please note that none of the information listed is considered infallible or unchangeable. Also, this list is not exhaustive. There are countless ways to make compost and every way has specific benefits, nuances, and best practices. What is written here is meant to act as a general guide to compost methods while including some of the generalities of each method. It is intended to act as a springboard. Take the information and adapt it to your own needs. Finally, it is not within the scope of this document to discuss the specific details of each composting method listed. There are some resources provided to try to help readers further pursue specific styles.
WHAT is compost?
- Simply stated, compost is organic matter that has been decomposed by microorganisms in an aerobic environment (in the presence of oxygen) that has sufficient water.
- Please note that there are some methods of decomposing organic matter in an anaerobic environment in order to make a compost product (for example, bokashi). Those methods will not be discussed here.
WHY do we compost?
- There are multiple reasons for composting. Listed here are several of the more popular ones. Note that not every composting method listed in this article will address all of the following reasons for composting.
- Decompose organic matter, turning waste streams into valuable resources, thereby keeping more materials out of the landfill, where they contribute to greenhouse gas emissions and climate change;
- Provide a healthy soil inoculant for the land- spreading material with a diverse and abundant quantity of soil microorganisms;
- Add organic matter to the land;
- Sequester carbon in the soil;
- Kill plant seed in the material;
- Kill potential human and animal pathogens in the materials.
HOW does compost happen?
- Time and sometimes heat. Some composting styles just take time and some take a combination of time and specific temperatures to reach the desired finished product.
A note about high desert composting
While most of the general composting techniques hold true regardless of where one is in the world, the act of composting in each climatic region will have its own subtle variations. For the arid, southwest region of the United States, the main additional consideration is a quicker loss of moisture from compost piles compared to more humid and/or wetter areas of the world.
- Several tips to help with pile moisture:
- Keep a close eye on moisture levels. The simple act of paying attention to this facet will be a big help. You may need to check every day during the hottest times of the year. The “squeeze” test for moisture will tell you how wet the inside of your pile is.
- Cover the pile! Using a breathable cover in the warm months will help keep more moisture in and still allow heat to dissipate and oxygen to enter. Using a non-porous cover in the cold months will help to keep both moisture and heat in the pile. Make sure that when using a non-porous cover, there is space at the top of the pile (and the bottom of the pile if possible) for oxygen exchange to continue.
- A closed bin versus an open pile will also help keep moisture in.
- Daily spraying or misting of the outside of the pile is an option in the heat. A thin layer of dry/crisp material on the outside of the pile is okay but a quick spray will help to keep it from getting too dry
- If possible, consider setting up an automatic irrigation/watering system to lightly mist the outside of the pile at regularly scheduled times during the hottest months. Be careful with the setup, though, because the opposite problem, a pile that is too wet, is just as bad as a pile that is too dry.
- Place the compost in the shade in summer months. If this is not possible then the pile or bin may be covered with two layers of shade fabric or cardboard.
- For more information on high desert composting, visit the Bernalillo County Master Composters