Composting is one of the most fundamental practices a gardener can engage in, and is a process used on any permaculture site. It recycles organic “waste” and turns it into valuable, highly useful material which is used to enrich the soil in vegetable beds, and around trees and other plants. This practice, returns nutrients to the soil and enriches the overall quality of topsoil which otherwise would become depleted over time. In the practice of permaculture, we want to enrich our soil over the long run, not diminish it. Good compost has the capacity to increase yield and increase carbon sequestration in organically managed soils.
The stewardship of our soil’s fertility is of the utmost importance. Just as humans have a need for food, the soil has a need to be replenished. Agrarian people around the world know that their livelihoods depend on the sustainable fertility of the land that they farm. The nutrients that are taken out of the soil in the growing of the plants that feed us need to be replaced, and this is where composting comes into play. For most of us who practice small-scale permaculture, we’re referring specifically to the soil used in our vegetable beds and in growing our fruit and nut trees. Our health is dependent on soil nutrients that are available to the plants we eat; soil health and human health are intimately connected.
Compost is created as a result of millions of microorganisms breaking down organic material and turning it into “black gold” which we then add back to our soil to replenish it. Our job as responsible stewards of the soil is to provide the best conditions for these microscopic organisms to flourish and do their thing.The most common way to create compost is by building a compost pile, and while there is not necessarily just one method or technique for constructing and maintaining a compost pile, there are some time-tested guidelines that will be the focus of this article for creating rich, nutrient-dense compost:
You will be limited to what materials you can get your hands on, but having a variety of organic materials in your compost pile will be advantageous. These materials might include, grass clippings, table scraps, cardboard, newspaper, old natural fiber clothing (cotton/wool/silk/linen and more), leaf litter, and plants removed from your garden at the end of the growing cycle. I like to collect leaf litter from the city park in the Fall to add to my compost pile. Animal manure, if you have access to it, is a beneficial additive to increase the population of microorganisms and accelerate the decomposition process and increases nitrogen content. Manure from chickens, horses, pigs, sheep, goats and alpacas is commonly used. Horse manure is not as well digested as other manures so a hot compost is desirable if this is in the mix. Poultry/bird/bat and pig manures can be used in smaller ratios as they are particularly potent.
A good carbon:nitrogen ratio is considered to be 30% carbon to 1% nitrogen. Don’t drive yourself crazy trying to get this exact ratio, but do your best to make sure you get both carbon and nitrogen into your pile. Carbon is the primary food source for the bacteria doing the work of making compost.
Nitrogen fixing tree material
If at all possible, consider adding leaves from nitrogen fixing trees or bushes to you compost pile. This could include leaves, from mesquite, black locust, and alder trees.
Make sure oxygen can get into your compost pile. This is done by turning your pile periodically which speeds the decomposition process. If your compost pile begins to smell bad, then it has become too wet and anaerobic bacteria (non-oxygen loving) are thriving. Aerating by turning helps encourage aerobic bacteria (oxygen loving). All those microscopic organisms in your compost pile are like humans in that they need food, air and water to thrive. Give them oxygen by turning your pile. When turning your compost put drier, still recognisable materials toward the center where conditions will better support decomposition.
Manage the moisture in your pile! In our arid climate (monsoon period is an exception) small, regular waterings are essential for materials to break down. One sustainability group at UM Las Cruces waters their compost piles for one minute each day. If you can build your compost under a tree for shade. This helps keep conditions moist and keeps the sun from destroying nutrients once finished.
Size of compost pile
According to Kate Tirion, a functional compost pile has a minimum volume of 4′ x 4′ x 4′, used wood pallets and T posts can be used to build bins, cardboard lining (stapled in place) helps keep moisture from wicking out and will break down eventually. The idea is to keep your compost pile consolidated rather than spread out, encouraging microbial activity which generates heat within the compost pile as microbes digest carbon. This thermophillic activity can raise temperatures to 140 – 160 degrees Fahrenheit. This is a good sign that the compost pile is functioning properly and breaking down well. Hot compost that maintains these temperatures over 4 to 5 days kills pathogens and weed seeds, Bermuda grass, an African hot weather species, is best avoided in compost to prevent the spread of this invasive species.
Secondary decomposers will inhabit your compost as temperatures cool, some of these visible creatures include pill bugs/ roly polies, earwigs beetles, nematodes and more.
Resting your compost pile
Current research (UMLC) indicates that letting your compost rest after it has finished allows for the development of fungus which are proving to be more beneficial than bacterial focused composts – one community of microbes follows the other and both are essential in the process. A total of one full year for maturation, from start to finish, is suggested, allowing for beneficial fungus to develop in the cooled compost. During this phase remember the one minute per day moisture rule.
By following a few simple guidelines for composting, and being willing to experiment until you get it right, organic materials, which otherwise might have gone to waste, can be recycled and turned into a rich additive for the soils in our gardens and around our trees, restoring fertility and providing for a sustainable food supply.
Foot Note: When applying compost to trees and shrubs add an extra beneficial layer by covering compost with a layer of organic mulch at least one inch deep, extending beyond the drip line of these plants. This layer protects the nutrients in compost, keeps roots cooler and moisture in place longer; over time the mulch becomes top soil as well, creating beneficial habitat for soil microorganisms in the process. This is one example of stacking functions.