When people first get into (the wonderful world of) composting, it’s natural to assume that all types of composting - and the composts they produce - are basically the same. While there are indeed some parallels, there are also some very important differences. In this article we will be exploring both!
Here at PC, we’ve zoned in on 3 major categories of “composting” - what we refer to as our “BIG 3” methods. These are: 1) layered composting (basically the same thing as “backyard composting”), 2) worm composting, and 3) bokashi. We use the term “composting” (with quotes) because bokashi doesn’t technically qualify. By definition, composting is an aerobic (oxygen-requiring) process - while bokashi is anaerobic fermentation process.
That being said, bokashi does still need some form of aerobic decomposition (what we’ve called “Phase II” of the process) in order for the end product to be used beneficially in your garden.
Our BIG 3 methods tend to be the most common choices for people operating on a small-to-medium scale. Another important category - one, some experts might even argue is the only “real” type of composting - is of course thermophilic composting, aka hot composting. As the name implies, this approach requires that the mix of wastes achieves a sustained period of high temperatures at some point during the process.
What Can Be Said About ALL Forms of “Composting”?
- They involve the breakdown of organic wastes.
- More complex / less stable materials are converted into less complex / more stable materials.
- They require a balance of carbon-rich materials (“browns”) and nitrogen-rich materials (“greens”), a good supply of oxygen (at some point) and moisture, as well as adequate warmth.
- Microorganisms are critical, but other organisms can play a very important role as well.
- The end product (compost) is humus-rich and typically beneficial for soil and plant health.
- There is an important element of human control, or at least involvement (If a tree falls and rots in the forest…does it really compost? Nope!).
The good news is that pretty well any form of composting can offer at least some benefits. Even if you don’t get the process(es) perfect, you should eventually end up with something that’s going to provide a boost for your soil and plants!
What Factors Can Make One Compost Different From Another?
1) Temperature of the Process -
How hot a composting system gets - and for how long it stays hot - can have a major impact on the type of end product you end up with. In extreme cases, where poorly managed systems are allowed to overheat - with temps above 70 C (~160 F) - it can be more of a “cooking” than “composting” process. Definitely not ideal.
Composting that takes place at temperatures closer to ambient (known as the “mesophilic” range) will be a different process than even a properly-managed thermophilic process. With the former, there can be more conservation of nutrients, such as nitrogen, along with the potential for a very different community of microorganisms involved in the breakdown process, and in the end product. On the flip side, the lack of a thermophilic stage may increase the chances of there being pathogens and viable seeds in the compost (this can, however, depend a lot on the materials being composted).
2) The Organisms Involved -
We’ve touched on microorganisms, but there are also larger organisms that can play a major role in determining the type of compost you end up with. The most well-known example is, of course, composting worms. The passage of organic matter through an earthworm’s digestive system involves a very unique breakdown process, and it results in a correspondingly unique (and highly beneficial) end product.
3) Types of Materials Being Composted -
Composting different types of materials will naturally result in different types of composts! For example, composts made exclusively from bedded livestock manure are likely going to be a fair bit different from composts made with kitchen scraps and cardboard. Composting richer wastes tends to result in richer composts, as you might expect, but there are a wide range of factors that will ultimately determine how beneficial the end product is.
4) Type of Bins / Management Involved -
The vessels used (or lack thereof), and the way the systems are managed, can also have a major impact. Ideally, we want systems and management practices that will help us optimize the process as much as possible. E.g. With typical backyard/layered composting, using a container that helps retain moisture while still supporting excellent airflow may improve the process and the product (vs simply heaping our materials in an open compost pile). E.g. digging finished bokashi straight into your garden, or working with in-ground systems will be quite different from composting in a more typical system and then adding the finished compost to your garden. Relating to management, the experience level of the person doing the composting can also have a major impact on the quality of the output.
5) Duration of the Composting Process -
There is such a thing as “not enough” composting, but also “too much” composting. The former can leave you with an end product that isn’t properly stabilized; one that may contain phytotoxic (plant-harmful) compounds, potentially even pathogens. On the other end of the scale - finished materials that are simply left to sit for many months or even years - especially when exposed to the elements - can end up losing a lot of their nutrients and microbial potency. These overly-mature composts will still tend to be more valuable than the premature ones, though, since they’ll offer a great source of stabilized organic matter.
6) Composting Location -
Where the composting system is located can have a major impact on the process and products. Indoors vs outdoors is a big one. Composting indoors (when possible) offers much more control over the process, whereas outdoors you will be always dealing with the elements in one way or another. The more control you have, the easier it will be to achieve consistent, desired results. Outdoors, apart from the obvious potential impact of ambient temperatures, how exposed a composting system is to sunlight can also be a significant factor. During cooler times of year, full sun can actually be a blessing (especially with enclosed bins), since it can help to warm materials and boost microbial activity. During warmer months, too much sunlight can lead to excessive moisture loss and, in the case of mesophilic systems, overheating.
If you’ve made it to this point in the article and now feel even more confused and unsure about how to proceed, that’s completely understandable! There are a lot of factors and situations to consider and, unfortunately, there isn’t one “best approach” or compost that will be ideal for every single situation.
Here at PC, we are pretty biased towards worm composting. Not because we think it’s the only composting method people should use, but simply because it checks off a lot of boxes - especially for those with limited space.
- You have a team of composting helpers, working around the clock (for free), fragmenting, mixing, aerating - and just generally, optimizing - the waste materials for the microorganisms that do the lion’s share of the work.
- It offers a great deal of flexibility, in terms of scale and location. You can easily compost indoors or outdoors, in systems small, large, or anything in between!
- It pairs really well with most other forms of composting.
- The end product of the vermicomposting process is also distinctly different from that of any other types of composting. Passage through the worm digestive system imparts some unique properties and biology that makes vermicast a particularly special material to work with.
- Apart from having unique, beneficial properties, the amount of vermicast needed to showcase these benefits is relatively small, compared to most other types of compost.
Of course, not all worm castings are created equal either - but creating your own can eliminate a fair amount of the uncertainty, since you are the one in control of the materials and process!
Bringing it All Together - Our Recommendations
Do Your Own Research - Learn about different composting methods, study recipes and guidelines recommended by others, ask questions, and then…
Make Your Own Composts - There is something special about taking matters into your own hands (literally). As “easy” as it is just to grab some bags of “compost” at the store, it’s difficult to know for sure what all went into it and how it was made. Making your own puts you in the driver seat, with full control over materials and methods! Just making the stuff isn’t enough, though - you should also…
Test Relentlessly - Don’t just assume compost = compost = compost (the major point we’re trying to drive home in this article) and treat it that way. Keep testing different composts in different applications, to see what really works well where/when.
Get Composting Worms Involved - If at all possible, we highly recommend using composting worms at some point in your overall process, since they offer so many great benefits (highlighted above). As great as worms are, however, we still recommend that you…
Combine Different Methods - As touched on, there is no one “perfect” type of composting or compost. Combining approaches can be a great way to get the best of both (or multiple) worlds. E.g. maybe you have thermophilic heaps for bedded manure removed from your animal stalls. This is a great starting place - but consider then adding partially-composted manure to a vermicomposting system! E.g. bokashi offers a great way to deal with a wider array of organic wastes in a small amount of indoor space - but, for best results, the “finished” material should then be processed aerobically in a more typical composting system.
Don’t Forget About “Liquid Composts” - Compost extracts and teas can be an amazing way to spread your (“never-enough”) supply of quality compost even further! Just make sure you are following trusted guidelines when making them so as to avoid some of the potential pitfalls and hazards.
Nearly all of us have the resources and potential to make our own quality black (or brown) gold. Maybe every batch won’t be perfect - especially early on - but with some dedication, the proper guidance, and a little love, both the experience and the results can be pretty special!
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Layered Composting - A Simple Backyard Method to Build Nutrient and Microbe Rich Compost!
Bokashi - A Simple, Effective Method for Beneficial Kitchen Waste Conversion!
Bokashi - Phase II Turning Your Pre-Compost Into Beautiful Black Gold!
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