Composting and Deep Mulching

Explorations in Ecology for Children and Their Adults: Transformative Adventures for All of Us

Note: For now, this blog is a serialization of a book titled Explorations in Ecology for Children and Their Adults: Transformative Adventures for All of Us. Here is the preface. The first adventure is Taking Education Outside.

Introduction

Composting and top mulching are amazing ways to take advantage of a natural process to reduce waste that leaves our home system and to obtain a yield (two of my favorite permaculture principles) from our plant-based kitchen and yard scraps. That natural process is decomposition, a type of breakdown process we discuss in the Synthesis and Breakdown field trip. While decomposition gets called many names like decay, rotting, and spoiling, without it, life would quickly bind up all readily available nutrients in large organic molecules (e.g., carbohydrates, proteins, fats, and nucleic acids) and the great cycle of life would come to a grinding halt.

This field trip is an ongoing one. Here, you’ll learn about a variety of ways that you can team up with other organisms to facilitate decomposition. Hopefully, you’ll be composting in one way or another forever! This field trip is a great follow-up to the Synthesis and Breakdown field trip mentioned above. It also goes along nicely (either before or after)  Playing in the Dirt.

Activity

Understanding Why Composting is a Field Trip for All of Us: As we see in the Observing Loops in Nature field trip, wild ecosystems continuously regenerate themselves by recycling nutrients. Factory farming and other forms of ecosystem destruction have made soil depletion a worldwide problem (Some say we have less than 60 years of topsoil left). Sending our kitchen scraps and/or yard waste to toxic landfills contributes to this problem. Even if you don’t garden and have no house plants, your family can leak value into your ecosystem by composting your kitchen and yard scraps.

Maintaining a Centralized Compost Pile: The easiest way to compost kitchen scraps at home is to keep a 5-gallon bucket with a lid under your sink. Put all of your plant-based kitchen scraps in the bucket: coffee grinds, banana peels, and vegetable trimmings and leftovers that went bad in the back of your fridge, all make great additions to your compost collection. This can include eggshells but no other animal-based scraps (they’ll decompose just fine but may attract unwanted guests like rats or bears, depending on your location). When the bucket is full, create a compost pile by emptying your bucket in a fixed location in your yard or local community garden. Covering your pile with a layer of leaves will aid decomposition and make your pile look more aesthetic.

Protecting a Centralized Compost Pile: If an exposed pile doesn’t work for you you can dig a hole in your yard and just bury it and let nature take its course. If you have plans to do a garden, bury your compost under where you plan to garden. You can also enclose your pile, just allow for plenty of air circulation in your enclosure. I’ve used concrete blocks turned on their sides and upcycled pallets to make compost enclosures. I stay away from those plastic turnable bins. They disconnect your pile from the Earth, support the plastics industry and, to top it all off, don’t work very well. Where I live, in addition to walls, our compost enclosures need to be covered and have hardware cloth underneath to keep out burrowing creatures.

These forms of passive composting are not the fastest way to get usable soil from your compost but it does reduce waste, obtain a yield, and close a loop at home! Make sure to engage your kids in the process including checking on the status of the materials recently added to your centralized compost whenever you add to it. Ask them to predict what they’ll see before you look and describe what they see and smell and explain what they think is happening after you’ve checked out your compost.

Speeding up the Decomposition Process: You can speed up the decomposition process by turning your pile weekly, keeping your pile as moist as a damp sponge, and attending to the proportions of various types of organic matter in your pile as discussed in the Some Nature Science Stuff section of this field trip. Vermicomposting is also faster than passive composting.

Vermicomposting: Vermicomposting or composting with worms is essentially the same as maintaining a centralized compost pile with the addition of a specific species of worm commonly called red-wigglers (Eisenia fetida). Red-Wigglers, unlike Earth Worms, don't love soil. They do best in manure, compost, and other decaying organic matter. They are available over the Internet, and Peter has always gotten his from friends or when desperate, a store that sells fresh fishing bait. If you get yours from a bait store make sure you get red wigglers, not nightcrawlers. The product of vermicomposting is called worm castings (a fancy name for worm poop). One company that sells worm castings calls it black gold because it is so expensive to buy. It’s pricey because it makes an amazing top dressing. Because it is hard to produce in quantity, Peter only uses it on container plantings and for emergency rescues of neglected plants. 

The simplest way to start vermicomposting is to add some wrigglers to your compost pile. You’ll probably need a compost enclosure to protect your worms from birds and borrowing mammals who tend to love worms! You may even need hardware cloth under your bin. Peter’s vermiculture set-up is a square bin made from two tiers of concrete blocks covered with a sheet of recycled plywood. Once you’ve established a bin,  stop adding new material to one side about a month before you want to harvest castings. Harvest castings by emptying the side that hasn’t been fed for a while onto a flat surface and, usually with the help of children in my nature activities, pick out as many worms as we can to return to their friends in the pile. Then, put the castings through a sifter. Peter made one with 2 x 4s and some ¼ inch hardware cloth.

Making Life Easier with Deep Mulching: Ecological design is more than the Hippocratic Oath: “do no harm”, applied to ecosystems. It includes designing systems that work with their surrounding ecosystems, by working as ecosystems. How does decomposition happen in ecosystems? Nutrients in the form of plant and animal parts and excretions fall from above to the ground where, as we discuss in the Nature Science Stuff section of the Relational Gardening post, “tiny crystals, grubs, bacteria, fungi, nematodes, worms, poop, pee, decaying parts of bodies and exudates all gather and make beautiful biological music together.” The result of this performance is the release of nutrients that slowly leak value into the soil below.

Top mulching or composting in place is simply the practice of doing what plants and animals do: dropping organic matter on the surface of your garden and yard. This creates a layer of organic matter like you would find covering the ground in a forest. We use bark, sawdust, wood chips (you can borrow a chipper from a neighbor, hopefully), sticks, branches, and other materials from his yard to top mulch. Your local city’s sanitation department may offer free mulch, as well! While compost piles work best with a mixture of yard and kitchen scraps, most people use only yard scraps (and select kitchen scraps like eggshells, coffee grounds, and nut shells) for top-mulching to avoid attracting unwanted visitors. David Braden of the Living Systems Institute uses chickens to process his kitchen scraps and then adds their bedding complete with processed kitchen scraps (AKA chicken poop) to his top mulch. For more information on top mulching with or without chickens see David’s write-up on deep mulch gardening.

Some Nature Science Stuff

Fungi and Bacteria are the Workhorses of Decomposition

While macroinvertebrates (visible creatures with no spines) like arthropods (a large phylum that includes insects, spiders, centipedes, and millipedes) and worms help break compost into smaller pieces, fungi, and bacteria do most of the work in decomposing organic matter into a form usable by plants. Fungi are a very diverse kingdom, neither animal nor plant. Fungi exist in many forms including single-cell yeasts and molds and multicellular organisms. Many fungi, including most species that produce mushrooms, can break down lignin and cellulose, two very hard-to-break-down structural plant molecules. Multicellular fungi exist mostly as mycelium, a network of fungal threads called hyphae. Mushrooms are the “fruiting body” of some kinds of mycelium. In addition to mushrooms, the other visible forms of fungi are mycelial cords and rhizomorphs.  Both are bundles of hyphae that grow in the ground or on trees. Many fungi are saprophytic meaning they feed on decaying matter and are therefore welcome guests in our compost piles. If you look carefully, you're likely to find fan-like visible white threads composed of bundles of saprophytic mycelium growing through your compost. 

Bacteria, like the decay they often facilitate, have a bad rap for several reasons. The first is that some are pathogenic (i.e., disease-causing). However, many are also beneficial. Many animals, including humans, depend on beneficial gut bacteria to help with our digestion. Healthy soil and compost also depend on beneficial bacteria. The second reason for bacteria’s tarnished reputation is that some bacteria that feed on dead or dying organic matter are anaerobic. Anaerobic bacteria do their work where oxygen is in short supply including in very wet material like that in compost buckets or dead bodies. And, Anaerobic decomposition stinks. People who keep their compost in a bucket before bringing it outside have ample opportunity to experience and talk about aerobic and anaerobic bacteria. Aerobic bacteria do their work with the help of oxygen.  The byproducts of aerobic decomposition smell like good soil. For a variety of reasons, our goal for our compost, once it gets outside, is aerobic decomposition. Worry not, as a little anaerobic decomposition in the bucket won’t hurt.

The last distinction between different species of bacteria that we’ll discuss here is their preferred temperatures. The two types most involved in decomposition are mesophilic and thermophilic. Mesophilic bacteria prefer temperatures of  68-113° F (20-45° C).   Thermophilic bacteria like it hot, between 122-140° F (50-60 ° C). Hot composting relies on a fairly large compost pile where mesophilic bacteria get your pile up to the temperatures where thermophilic bacteria like to work. The benefit and disadvantage of hot composting is that the high temperature tends to kill off not only seeds but also other life in the compost. These features make hot composting most suitable for large-scale composting operations like a community compost site.

Proportions

As we’ve mentioned, decomposition happens whether we want it to or not. And, we can speed up the process by attending to the proportions of the ingredients in the mixture. The key ingredients we need to monitor and adjust are water, air, green materials, brown materials, and grit. In terms of air, you just need to keep your compost fluffy and perhaps turn it over every once in a while (maybe weekly- you’ll learn this with experience), and do not add too much water. Worms, like all living beings, need water to do what they do. Too much water will turn your pile into a stinky anaerobic mess. The Goldilocks zone for water in a compost pile is to keep it about as wet as a damp, but not dripping sponge.

Thinking about green and brown materials is a way to try and balance the proportions of nitrogen and carbon in your pile. The basic idea is that if you use green and brown materials equally in your pile you’ll end up with a good balance of carbon and nitrogen. Both green and brown stuff have lots of both carbon and some nitrogen. Brown materials have a relatively high proportion of carbon to nitrogen while green materials have relatively more nitrogen. Green materials include manure, grass clippings, kitchen scraps, fresh weeds, and any green plant materials. Brown materials include straw and hay, fallen leaves and pine needles, shredded paper, cardboard, wood chips, sawdust, twigs, and bark.

Educational Suggestion

The flow of activity in factories follows a prescribed plan. In factory-like schools, this plan is called, “the curriculum.” The curriculum specifies both scope (what gets taught) and sequence (the order in which topics are covered). We’ve both worked with many educators who plan their entire year before meeting their students on the first day of school. In forests, beings learn as they seek to fulfill their needs and bump into others along their way who are also trying to fulfill their needs

In the kinds of learning environments and communities that we nurture, the curriculum is negotiated, emerging from the intersection of the wants and needs of, and interrelationships between, learning guides and learners. Unlike lock-step factory-style curricula, designed by adults and imposed on children, negotiated curriculum designers plan activities based on children’s interests and respond to children’s interests during those activities. Negotiated curriculum shares those features with emergent and student-driven approaches. The difference is that educators interested in co-creating and negotiating the curriculum with children have an agenda. In our case, that agenda is helping them become more ecological. This includes learning the players in their home ecosystem, understanding how ecosystems work, and being able to participate in the dance of interdependence with their ecosystem by meeting their own needs while also attending to the needs of the rest of their ecosystem. Rather than imposing our agenda on children we share our agenda with children  (e.g., talking about feedback loops) and make decisions together about incorporating that agenda into our shared activity.  So please, do not think of these field trips as a fixed prescription of your activity. Our intent is to give you some ideas of activities to engage in when the time is right at a pace that works for your group.  

Wrapup

Remember that composting is just you facilitating a natural process that would happen anyway, even without your intervention. So you don’t have to worry much about doing it right. This is a skill that you can continue to learn over a lifetime. Most importantly, any way that you can avoid sending your kitchen and yard scraps to a landfill is helping out Mother Earth by closing a loop at home and leaking value into your ecosystem!