Composting is the controlled partial decomposition of organic materials (those with plant and animal origins) by aerobic or anaerobic biodegradation. It creates moist environments that stimulate the growth of decomposer microbes, although larger creatures such as earthworms and ants contribute to the process. This has the effect of providing and "stabilising" the nutrients, sanitising pathogens in the organic material, increasing the amount of organic matter and producing a useful soil amendment by improving the soil structure. There are a wide range of approaches to composting that require different infrastructure, inputs, and produce different outputs.

Compost is a common name for humus, which is the result of the decomposition of organic matter. Decomposition occurs naturally in all but the most hostile environments (such as buried in landfills or in extremely arid deserts, which prevent the microbes and other decomposers from thriving).

Purpose[edit | edit source]

There are two main purposes of composting:

  • it is a waste management technique as it reduces the volume of waste materials. In some circumstances it may also have a beneficial sanitising effect on dangerous microbial pathogens in the waste
  • creation of compost from the plant matter, which is a very useful compound in farming. It is useful for this as
    • it improves soil structure, improves aeration, water-retention, erosion problems, and makes the soil easier to work.
    • when used as mulch, it slows the growth of competitive weeds between rows and around plants. See mulching for further details.
    • it adds nutrients and organic matter to the soil. As a sponge holds water, so organic matter helps to retain nutrient ions in the soil that the plants need to grow. These nutrients may not have originated in the compost - so soils with higher levels of organic matter can be said to be more fertile than those with much lower levels.

Inputs[edit | edit source]

Rather than allowing nature to take its slow course, composting provides an optimal environment in which decomposers can thrive. To provide a healthy environment (and nutrition) for the most active microbes (rapid decomposers, bacteria), the compost pile needs the proper mix of the following ingredients:

  • Organic matter - the larger the pieces the slower the decomposition
  • Oxygen and water: whilst composts can be too dry, it is more of a problem when it is too wet, as the water displaces oxygen within the matrix, which may prevent efficient aerobic microbial activity. Therefore, rapid bacterial decomposition requires a moist but not soggy environment.
  • Easy sources of carbon and nitrogen: a moderate carbon to nitrogen ratio of around 25:1 is required for hot aerobic composting. Limitations in either may lead to reduced growth of beneficial microbes
  • Optimal temperatures: 'friendly' compost microbes multiply at higher temperatures.

Decomposition happens even in the absence of some of these ingredients, but not nearly as quickly and not nearly as pleasantly (for example, the plastic bag of vegetables in your refrigerator is decomposed by microbes, but the absence of air encourages the growth of anaerobic microbes that produce disagreeable odors).

When conditions are not optimal, the process may be slowed, may not happen at all, or may not destroy harmful microbial pathogens. Care should be taken as it is possible to have areas of poor conditions within a compost heap that is performing well. High or low levels of moisture may also have a impact on the length of time it takes for the organic material to stabilise into compost. Compost is dark in colour (exact colour will depend on the materials used), consistent (in the sense that it is hard to identify what was used to make it), is fairly fine and does not contain many contaminants (such as pieces of plastic, large pieces of wood and pieces of uncomposted wastes).

In most places with good management, stable compost can be produced within 8 weeks. However systems which are not ideal (sometimes known as cold composting) may take a lot longer. Composting toilets should be left to mature for at least a year after use and may still not be fully stable.

Composting is the cumulative digestion effect of many different kinds of organism and may involve several different steps and various types of organism, which may include worms, microbes and other biota.

Outputs[edit | edit source]

Old fan cases make excellent sieves for separating small and large bits of compost.
  • Cool compost piles produce insects and worms.
  • Well built aerobic composting produces heat.
  • At the end of composting you have relatively stable humus.

Decomposers[edit | edit source]

All guidelines for building compost piles have the goal of creating the proper environment for a decomposing ecosystem. The ecosystem in a compost pile is a microcosm of larger ecosystems. The correct environment must be maintained for a healthy and vigorous community of decomposers. In addition to the decomposers that work directly on the organic content of the pile, compost piles provide habitat for those that prey upon direct decomposers. Their waste also becomes part of the compost material.

The most effective decomposers are bacteria and other microorganisms. Also important are fungi, protozoa, and actinobacteria (or actinomycetes, bacteria that are often seen as white filaments in decomposing organic matter). At a macroscopic level, earthworms, ants, snails, slugs, millipedes, sow bugs, springtails, and others work on consuming and breaking down the organic matter. Centipedes and other predators feed upon these decomposers.

Compostable materials[edit | edit source]

Compostable materials are those which biodegrade completely into substances which are healthy or at least harmless for soil and plants. In general, anything which was once living can be composted, although some materials are more convenient to process than others. To be on the safe side, always wear gloves when handling compost, and try to avoid allowing compost to have any contact with eyes, mouth, or breaks in skin.

Kitchen and household waste can be reduced by composting as much of the organic refuse as possible. However, not all household and kitchen waste can be composted, so it's helpful to know what can be and what can't.

Plant materials[edit | edit source]

In general, plant-based materials are easy to handle and pose fewer health risks to humans.

  • Coffee grounds
  • Some tea bags (a staple may be ok, but many bags sold in the US contain a small amount of plastic. This is not very harmful, but is not perfectly compostable - you can tear off the top and throw in the regular garbage, and just compost the tea leaves & lower portion of the bag.)
  • Green waste from the garden, dead tomato plants after the autumn frost, weeds, etc.
  • Yard waste (lawn and hedge clippings). Woody waste will degrade faster if you shred it before adding it to the pile. Large intact limbs may take years to fully decay. If you cannot reduce the size of large wood chunks, place them toward the bottom of the pile so they are subject to the most possible heat and moisture.
  • Leaves - if you live around deciduous trees, you can collect huge amounts of leaves for your compost pile. If your neighbors place their leaves and yard waste at the curb for collection, you can rescue it for your compost pile, thus saving the fuel cost of hauling it to a central processing facility. To reduce the volume of fresh leaves as quickly as possible, shovel old compost over them as you add them to the pile, and wet them down (preferably with graywater or rainwater rather than potable water). If no old compost is available, an alternative is to throw dirt on the pile, which will innoculate the leaves with microbes and break them down faster.
  • Old mushroom compost
  • Tree bark. Pine bark and some other forms of bark need to be composted for a period of some months to break down harmful components.
  • Vegetables
  • Fruit
  • Christmas trees - lop off the branches, add them to your pile, and save the trunks to use as very sturdy tomato stakes in your garden. You can set the trunks in the ground with a post-hole digger. After they rot and fall down you can compost them too. You can collect trees from all your neighbors when they discard them after Christmas. The branches take a long time to compost, unless you shred them first. If you can't shred them, put them directly on the ground, shovel old compost over them, and wait a year.
  • Kitchen scraps containing no animal products - putrescible wastes (i.e., that stink) attract flies and larger scavengers. Follow the same precautions as for kitchen scraps containing animal products.
  • Nuts and seeds
  • Crumbs
  • House plants
  • Natural fabrics (cotton, wool)
  • Wood shavings and sawdust

Animal materials[edit | edit source]

  • Egg shells - straightforward to compost, add calcium to the final product
  • Humanure and composting human feces (but take proper health precautions)
  • Urine - easier to collect and pour on the pile than faeces, poses far less health risk, and provides most of the usable nitrogen from human waste. Nitrogen from urine will feed the microbes that break down brown (carbon) materials.
  • Manure and liquid manure
  • Food scraps containing meat or bones - beware of pests. Meat scraps are often not advised as they can attract animals, but it depends on the context, the amount of meat, and whether the compost is securely covered. To eliminate odors and flies, shovel a thick layer of old compost or brown waste such as leaves over any fresh food scraps you add to the pile. It may help to arrange two piles, one that you add new material to, and one that you use as a source of old material to cover each addition of new material. While scavengers such as raccoons have extremely sensitive noses, there is a limit to how deeply they will dig into a compost pile. You can compost almost anything without attracting pests if you bury it deeply enough in unpalatable compost material. Materials such as meats, skin, etc. will become unpalatable in just a few days if the interior of the pile is active enough (i.e., hot and wet), but animal bones can remain attractive to pests for weeks. In cold weather, if the pile is dormant i.e. cold through the interior, food scraps may remain attractive to scavengers until the weather warms and decay resumes.
  • Hair trimmings, nail trimmings, fur from people or pets.

Man-made materials[edit | edit source]

Other[edit | edit source]

Some like to put special materials and activators into their compost. A light dusting of agricultural lime (not on the animal manure layers) can curb excessive acidity that can slow down the fermentation. Seaweed meal can provide a ready source of trace elements. Finely pulverized rock (Rock dust - Rock flour) can also provide needed minerals, as opposed to clay (which is trace mineral-poor and/or leached rock dust).

The animal manure part of compost source materials can be collected by composting toilets (in this case, human feces). However, such compost is usually not used as a fertilizer for plants that are directly edible (e.g., salad crops) but is instead be used on trees, bush fruits or else on the ornamental garden. Most composting toilets do not allow for the thermophilic activity needed to completely kill off the pathogens and bacteria. However, there is research that shows that if these high temperatures are reached, there is no danger of contamination, and the resulting compost can be safely used on food crops.

Non-compostable materials[edit | edit source]

  • Meat and bones (can be composted but it is not advisable in home composting)
  • Cheese
  • Dairy products
  • Cooking oils
  • Plastics
  • Foil
  • Glossy magazines
  • Disposable feminine products
  • Stickers, sticky tape

Carbon/nitrogen ratio[edit | edit source]

It is important to understand the carbon/nitrogen (C/N) ratio as this will have a dramatic effect on the success of a composting system. The most rapid composting occurs with the ideal ratio (by dry chemical weight) of carbon to nitrogen, from 25-to-1 to 30-to-1 or lower. In other words, the ingredients placed in the pile should contain 30 times as much carbon as nitrogen. For example, grass clippings average about 19-to-1 and dry autumn leaves average about 55-to-1. Mixing equal parts by volume approximates the ideal range. Commercial-grade composting operations pay strict attention to this ratio. For backyard composters, however, the charts of carbon and nitrogen ratios in various ingredients and the calculations required to get the ideal mixture can be intimidating, so many rules of thumb exist to guide composters in approximating this mixture. (For more information check Compostable materials, an introduction to different types of materials that can be effectively composted)

High-carbon sources provide the cellulose needed by the composting bacteria for conversion to sugars and heat.

High-nitrogen sources provide the most concentrated protein, which allow the compost bacteria to thrive.

Some ingredients with higher carbon content:

  • Dry, straw-type material, such as cereal straws
  • Autumn leaves, browned plants
  • Sawdust and wood chips
  • Some paper and cardboard (such as corrugated cardboard or newsprint with soy-based inks)
  • Woody materials. If using woody materials, chopping will be necessary as the microbes require a high surface area to get to the carbon in the wood, which is often stored in a way that is difficult for them to access. On the other hand, having larger pieces of material within the compost may assist the process as it will aid air circulation. It may be necessary to remove these towards the end of the process.

Some ingredients with higher nitrogen content:

  • Food wastes
    • Greasy food waste and wastes from meat, dairy products, and eggs should not be used in compost because they tend to attract unwanted insects and other animals. Eggshells, however, are a good source of nutrients for the compost pile and the soil although they typically take more than one year to decompose.
  • Fresh green plant material (fresh or wilted) such as crop residues, hay, grass clippings, weeds
  • Animal manures (from vegetarian animals, not carnivores)
    • Poultry manure provides lots of nitrogen but little carbon. Horse manure provides both. Sheep and cattle manure don't drive the compost heap to as high a temperature as poultry or horse manure, so the heap takes longer to produce the finished product.
  • Fruit and vegetable trimmings
  • Seaweeds
  • Used Coffee grounds
  • Sludges, human sewage sludge

In an attempt to judge the proper mix of materials, different rules of thumb are available. Some prefer to add one basket full of nitrogen source followed by one basket of carbon source. Mixing the materials as they are added increases the rate of decomposition, but some people prefer to place the materials in alternating layers, approximately 15 cm (6 in) thick, to help estimate the quantities. Keeping carbon and nitrogen sources separated in the pile can slow down the process, but decomposition will occur in any event.

Systems and approaches[edit | edit source]

Aerobic vs anaerobic[edit | edit source]

  • Aerobic composting - the careful assembly of materials and moisture into a pile that rapidly heats up either in a windrow or a bin, to produce a high quality compost that can be used in gardens, particularly for clean cultivation.
  • Anaerobic composting - Also known as the Indore method, where materials are kept moist in a sealed container in the absence of oxygen.

Aerobic[edit | edit source]

There are two primary methods of aerobic composting:

  • Active (or hot) composting: In ideal conditions, the rapid respiration of microbes within the compost will lead to high temperatures and so this is sometimes refered to as "hot composting". Higher temperatures are highly desirable as it will allow the most effective decomposing bacteria to thrive, denature pathogenic microbes (who are usually most active at around body temperature) and seeds of many species of weed and rapidly produces usable compost.
  • Passive (or cold) composting: Letting nature take its course in a more leisurely manner and leaves many pathogens and seeds dormant in the pile. Cold composting is composting in sub optimal conditions. Materials may be left in heaps without attention, mixing or protection from rain. Composting may be slow, may not take place at all or the conditions may even encourage undesirable processes to occur. Cold composting should therefore be avoided and the products may need additional processing or composting to be safely used.

Most commercial and industrial composting operations use active composting techniques. This ensures a higher quality product and produces results in the shortest time (see compost windrow turner).

Home composters use a range of techniques varying from extremely passive composting (throw everything in a pile in a corner and leave it alone for a year or two) to extremely active (monitoring the temperature, turning the pile regularly, and adjusting the ingredients over time) and combinations of both.

Some composters use mineral powders to absorb smells, although a well-maintained pile seldom has bad odors.

Microbes and heating the pile[edit | edit source]

An effective compost pile is kept about as damp as a well wrung-out sponge. This provides the moisture that all life needs to survive; in a compost pile, it provides an environment in which microbes can begin to do their work. Bacteria and other microorganisms fall into a variety of groups in terms of what their ideal temperature is and how much heat they generate as they do their work. Mesophilic bacteria enjoy midrange temperatures, from about 20 to 40 °C (70 to 110 °F). As they decompose the organic matter, they generate heat, and the inner part of a compost pile heats up the most.

The heap should be about 1 m (3 ft) wide, 1 m (3 ft) tall, and as long as is practicable – the advantage to making the heap at least 1 m³ (1 yd³) is that it provides suitable insulating mass to allow a good heat build-up as the material decays. The ideal temperature range hovers around 60 °C (140 °F), which kills most pathogens and weed seeds and also provides a suitable environment for thermophilic (heat-loving) bacteria, which are the fastest acting decomposers. The centre of the heap should get quite warm, possibly hot enough to burn a bare hand. If this fails to happen, common reasons include the following:

  • The heap is too wet, thus excluding the oxygen required by the compost bacteria
  • The heap is too dry, so that the bacteria do not have the moisture needed to survive and reproduce
  • There is insufficient protein (nitrogen-rich material)

The solution is to add material, if necessary, and/or to turn the pile to aerate it.

Depending on how quickly the compost is required, the heap can be turned one or more times to bring the outer layers to the inside of the heap and vice versa, as well as to aerate the mixture. Adding water at this time keeps the pile as damp as a wrung-out sponge. One guideline is to turn the pile when the high temperature has begun to drop, indicating that the food source for the fastest-acting bacteria (in the center of the pile) has been largely consumed. After the temperature stops rising after the pile has been turned, there is no further advantage in turning the pile. When all the material has become barely recognisable from the original ingredients, turning into dark brown or nearly black crumbly matter, it's ready to use. Some practitioners like to leave the compost to mature further for up to a year as this seems to make the benefits of compost last longer.

Composting at different scales[edit | edit source]

Many different types of composting are conducted in different places around the world and at different scales. These range from bin composting at a household scale all the way to full industrial scale windrow composting.

Pile or bin composting[edit | edit source]

In fairly small scale composting, bins, piles and heaps are used. Bins may be produced from various different kinds of materials and can help to produce good compost if they assist with the flow of air through the heap. The disadvantage of bins is that the compost can be more difficult to turn and aerate. A heap on the ground can be seen as an easier option, however care may be needed to prevent the material from speading and to ensure it is adequately aerated. This page contains more information about home composting

Regarding the types of bin, plastic bins such as the geobin system have been used to produce compost of reasonable quality, but bins made of wood or other locally available materials can be used just as effectively. Sometimes bins have been designed with special equipment to aggitate and aerate the compost, which can also be a good way to ensure that the compost is properly aired without the user having to manhandle the compost.

See this technical brief about manufacturing bins.

This is a nice video by British composting expert Nicky Scott on home composting


Industrial scale composting[edit | edit source]

Windrows are large compost heaps which can be hundreds of metres long. They are usually this shape because specialist turning equipment is used to move along the whole length to turn and mix the compost. Arcata Marsh is an example of a large industrial scale composting plant.

Farm waste composting[edit | edit source]

In many farm systems, animal extreta from animal houses is mixed with urine and bedding and stored in bays beneath the buildings, to be excavated and removed at a later date. The effectiveness of this as a composting system will depend on the animals and the bedding materials used, but farmyard manure can often be used as a valuable soil amendment. In many areas it makes more sense to remove and store the waste away from the animal houses due to problems with dust and odors. Care should be taken when removing animal wastes from underground storage pits as there may be hazards from airborne pathogens and the material may not be adequately sanitized.

Pigs do well turning compost when left with it in a confined area (see Pigs turning compost)

Troubleshooting[edit | edit source]

  • Regularly turning compost to encourage the movement of air is always a good idea
  • Increase surface area of materials by chopping them up.
  • If your compost is smelly it is not getting enough oxygen (going anaerobic).
  • If space is an issue (ie if you are living in a house or apartment with not much of a yard), you could try vermiculture (i.e. using a worm bin).
  • Animals (ie bears, raccoons, rats, and other animals) may become a problem if there is something in a compost pile they would like to eat. Access to compost must be restricted (ie by using a high, fully closed bin); avoiding the scraps that attract them too can help, especially meat, fish.

This is another video about troubleshooting home compost


See also[edit | edit source]

External links[edit | edit source]

Projects for Schools

Discussion[View | Edit]

Subpages[edit source]

Talk:Composting/editedversion_11-12 - comments on the content as of Nov 2012

Talk:Composting/removed 2013-02

Review of introduction[edit source]

Responding to some recent edits - I think there are some errors

From Wikipedia: Humification: The process of "humification" can occur naturally in soil, or in the production of compost. It's an obscure word for referring to composting, and it's also broader than composting. It is not quite a synonym for composting.

It's true that humification seems to be used mostly for the natural anaerobic digestion of green manure. Still, it's but a partly digested material so I prefer the other word. However, as the article is more or less correct now, we'll leave it at that.

KVDP 00:27, 10 November 2012 (PST)

"Compostation" (used in a previous version of the page) I suspect many English-speakers will have the same reaction as me to this word - it sounds at first like a made-up word. But I looked it up, and it's actually in use, in serious contexts. However it's very obscure, and I would rather not see it given prominence.

In standard English, compost is the correct noun for the substance, and composting is the correct noun (verbal nounW or gerundW) for the process. Either would be fine as the title for the article. (I only mention the grammar because of an editor's insistence on my talk page that "composting" was not a noun.)

I understand what a gerund is, but without a context/sentence (it's just "Composting" in the article name), composting seems to refer more to the act of humification, rather than "the composting process".
KVDP 00:27, 10 November 2012 (PST)
I think it's not a problem - definitely better than compostation. Compost is an acceptable alternative.
Your English is very good but I suggest that in questions about the finer points of language, we put more weight on the views of native speakers. Likewise in matters of Indonesian language, I will question and ask for explanations, but I will never presume to tell an Indonesian they are wrong on the subject. --Chriswaterguy 23:30, 11 November 2012 (PST)

At Wikipedia:Humus: In soil science, humus (coined 1790–1800; < Latin: earth, ground[1]) refers to any organic matter that has reached a point of stability, where it will break down no further and might, if conditions do not change, remain as it is for centuries, if not millennia. Compost is a mix of organic matter, a significant portion of which has not yet reached this stability - so if we use this definition of humus, it's more accurate to say "humus-rich compost" than to call the compost "humus". (It's not quite so simple, as the word humus is used in a number of different ways; however I using the soil science definition.)

Green manureW is grown as a crop. Kitchen and garden waste, common ingredients of compost, are not green manure.

Green manure =
1 a crop of growing plants, as clover and other nitrogen-fixing plants, plowed under to enrich the soil.
2 manure that has not undergone decay.


As we read, green manure is a crop (that's correct) but which has allready been uprooted (and is sometimes allready stuffed under te soil). So it's not a living/thriving plant, it's a dying one (when a plant is uprooted it starts to die, the same goes if you cover it entirely with soil) Not everything at wikipedia is correct, especially not when it comes to definitions.

Whether it's dead or not, it's green matter used on or in soil as "manure". It's not a general term for organic waste - as I said: Kitchen and garden waste, common ingredients of compost, are not green manure. --Chriswaterguy 07:26, 10 November 2012 (PST)
That's true, I didn't see that. I'll update the text.

KVDP 01:50, 12 November 2012 (PST)

regarding "Compost is a mix of organic matter, a significant portion of which has not yet reached this stability" from". In most cases, compost will allready have a small part being composted to humus (not everything composts at a same rate). However, it's incorrect to mention the compost in the definition as it's basically still digesting green manure (without humus). It's only when the whole thing is 100% humus that we call it humus. The phase in which the green manure started to digest and allready contains some humus, but is still not 100% humus simply has no name at all. As the line "Compost is a mix of organic matter, a significant portion of which has not yet reached this stability" from" you quoted, definitions on this may vary, I would like to know where you got this reference from (Wikipedia I guess, but where did the reference came from originally ?). KVDP 00:27, 10 November 2012 (PST)

That's not a reference - those are my own words. Look at any handful of compost with its bits of bark and other fibers, and you'll see what I mean.
I don't understand what you base your argument on - if it was humus, it would be called humus. If that were true, and you looked up humus and compost in any reference, it would then say they are the same thing - but it doesn't, and you'll find separate pages on the two topics, whether in Wikipedia or any other resource, because they are not the same thing. --Chriswaterguy 07:26, 10 November 2012 (PST)
I never said humus is the same thing as compost. I said that compost is green manure that is allready in process of digesting. Green manure is not yet being digested, although the plants are allready dying. Humus finally is completely digested green manure.

I hope that's helpful. --Chriswaterguy 03:31, 8 November 2012 (PST)

Joe's rewrite[edit source]

If I may just interject - there are a range of things being muddled up here.
Composting is a rapid processing of organic materials which stabilises them. But that does not mean you have created humus. Humus takes tens, hundreds and possibly thousands of years to form in the soil. It cannot accurately be stated that any person is engaged in humification. It can, however, be stated that they are composting. Green manure refers to two things: a crop which is grown for the purpose of adding organic matter to the soil, and also the act of adding green materials to the soil. It is true that green manure is not necessarily compost and that it may not have been stabilised. But compost is not the same as green manure either.
I don't think therefore it is correct to say that the purpose of composting is to produce humus, the purpose of composting is to produce stable compost. Over many years in the soil, when added as organic material, the compost may eventually become part of the soil fabric and be accurately described as humus. This is important because, of course, one can grow crops independently in compost without needing to add it to the soil first.
In my view this page should not mention humus because it is confusing and had nothing much to do with composting. But I also am less confused about that misuse of a word than why on earth you'd want to title this page humification or compostation. Joeturner 03:57, 16 January 2013 (PST)

I have edited quite a lot of this page because it was starting to annoy me. Some of it was just wrong. I lost the will to live towards the end. This article still needs major revision to be both accurate and usable. Joeturner 01:45, 5 February 2013 (PST)

well, I spent quite a lot of today changing this article. Some of the language was bad, some of the information was imprecise or wrong. There is still quite a lot to do, I intend to add more information and links from experts, possibly more pictures if I can find some we are allowed to use. Of course, this is all my opinion, but I am happy to defend anything I have changed to date. I have removed all references to humus and humification, which I think are inappropriate in this article. I have changed several titles, one of which was only found in a google seach back to this article and have rejigged the content. I am not really convinced that there should be any reference to green manuring or mulching, but as the existing content seemed to be pointing in that direction, I left it in. I have spent many hours removing carpet from sites where previous users thought it would work as a mulch. I refuse to believe that is something to recommend. In several places I replaced references to bacteria to microbes. It now has an introduction which repeats some of the content elsewhere in the article, which is not ideal, so I may change it again soon. Joeturner 09:26, 5 February 2013 (PST)
I discovered that much of the information on this page was repeated, often in a better way, on other Appropedia pages. I therefore simplified the style to make it an introduction to the subject and provided more in-line internal appropedia links into the text. Joeturner 02:12, 6 February 2013 (PST)

Purpose of this page[edit source]

I would like to propose that we need a clearer understanding what this page is for. I have substantially altered it for reasons I explained above. I intended to add additional content, but then discovered that the kind of things I was going to add were already on appropedia on other pages. It strikes me that composting is actually quite a large area of information, and so a single page cannot do it justice, and this seems to have been accepted by other editors - with a number of different pages focussing on different aspects. A number of these had better content than this page, so I have removed information that is better presented elsewhere and added inline links to those pages.

I now would like to suggest that this content (or perhaps something even simpler than this) would be better suited as an introduction to the subject on the Category:Composting and that this page is essentially pointless and might be better not to exist at all as a separate page. Joeturner 10:26, 6 February 2013 (PST)

Counterarguments to current rewrite[edit source]

Hi Joe, first of all, I wish to mention my thanks in taking the time to contribute at articles at Appropedia. That said, I think most edits you did were counterproductive (some were good too, ie adding in new links to Practical action documents. Then again, you also took out links (to In-depth explanation of bin composting, ...)

There are also several things you mentioned I'd like to respond to:

  • Humus takes tens, hundreds and possibly thousands of years to form in the soil. It cannot accurately be stated that any person is engaged in humification. I don't think therefore it is correct to say that the purpose of composting is to produce humus, the purpose of composting is to produce stable compost. Over many years in the soil, when added as organic material, the compost may eventually become part of the soil fabric and be accurately described as humus. This is important because, of course, one can grow crops independently in compost without needing to add it to the soil first.
You would need to implement references for such statements (all bold statements need references, at wikipedia, and at appropedia aswell). Also, I actually like to keep things simple (we're adressing unschooled people in developing countries and basic farmers in developed countries here, not rocket scientists), composting or humifation is a conversion process so you need to describe an actual end product. Humus fits that; perhaps it takes longer than what I thought to attain it, but that doesn't really matter.
  • It is true that green manure is not necessarily compost and that it may not have been stabilised. But compost is not the same as green manure either.
I never stated that it is. See the description: Composting is the act of decomposing organic waste (ie the whole plant->this has a link to green manure or specific plant parts, animal flesh, feces, ...) into humus using aerobic bacteria. So I actually mean by this that when the whole plant is used, that is green manure, and when feces, ... are used together with whole plants or just plant parts, it isn't green manure. You needed to analyse the text first.
  • You added several video's: I actually don't think that's an improvement as
    • many people lack the plug in to view it (myself included)
    • it severaly reduces the load time of the page; many people in developing countries have slow connections and will be severaly bothered by it
    • most people don't watch the full length of the video anyway, and learn little from it (printing the text allows people to learn the subject better)
  • I discovered that much of the information on this page was repeated, often in a better way, on other Appropedia pages. I therefore simplified the style to make it an introduction to the subject and provided more in-line internal appropedia links into the text.
It is a good thing that the same information is repeated on different articles. Else, people reading a single article may not understand another article (we can't expect they read every article at Appropedia).
  • I now would like to suggest that this content (or perhaps something even simpler than this) would be better suited as an introduction to the subject on the Category:Composting and that this page is essentially pointless and might be better not to exist at all as a separate page.
You end up wanting to delete an essential article (many article link to it) coming from a good article which is now corrupted and which you find you no longer find suitable any more. This way, the work of other people (nad your work aswell) will be destroyed. I don't think this is a good rewrite; it's better to revert it to this revision, then review what things you did you actually find an improvement, mention them here, and we'll then discuss the best way to implement these.

KVDP 02:05, 7 February 2013 (PST)

KVDP, thank you for your grace in replying in this manner. I appreciate that it might have been easier to explain the changes step by step, but eventually needed to change so much that I deemed it better to change and then argue about it afterwards. I'm sorry to say that I believe much of your content was actually wrong and so much needed to be changed that it was impactical to explain everything at the time.

As I said, I am completely comfortable to give reasons for my edits and to answer any points that you have as far as I am able to do so here. I accept that the page is nowhere near perfect, but am far more comfortable with it than what was presented before.

1. In-depth_explanation_of_bin_composting is a misnomer (it is not in depth), it is not really about bin composting and it is not accurate. I dispute the numbers in the table, for which you have provided no evidence or links), I dispute the implication that layering is the only or best way to make compost, I dispute the idea that lime is necessary (which you either wrote here or in some of the content I removed). I accept that this is one way to produce compost, but it is certainly not an indepth model which is widely applicable. The idea is sound, and either you need to improve the page until it says something which can be justified or the content needs to be imported into this page. In fact I do not believe it says anything which is not already said better elsewhere on appropedia, and that is why I removed it from the text. As you said to me, provide references as to why and how you believe this can be justified as an 'in depth explanation of bin composting' and I am very happy to provide links showing why the information is incorrect - or at best badly misleading.

2 I agree that this page should be simple as it is intended to be an introduction to the subject of composting, however we have never shied away from introducing and using technical language where appropriate. I don't believe anyone will ever come to appropedia looking for the word humification, because it is not a commonly used word. I submit that it is not a word that anyone involved in composting would use and I have given reasons above. Indeed, I don't really feel the need to justify that position, given you introduced the word even when other editors suggested it was inappropriate. There are many good references to humus which support what Chris and I have both said.

Material remaining in soils after removal of macroorganic matter (generally material that has been more extensively physically and/or biochemically transformed as a result of soil forming processes than macroorganic matter). There are two major classes: the nonhumic substances (e.g. amino acids, lipids, carbohydrates) and humic substances (a series of high-molecular-weight amorphous compounds). from The University of Wisconsin, Dept of Soil Science
Humus (one m) is the passive fraction of soil organic matter. It is a dark, complex mixture of organic substances that have been significantly modified from their original form over time, and it also contains other substances that have been synthesized by soil organisms. Usually, humus represents the majority of total soil organic matter, and it is relatively stable over time. from University of Vermont
There are scientists whose only job in life is to study humus dynamics in soils, for example see this link

Humus has a technical meaning referring to a fraction of soil which is important because it has complicated impacts on soil chemistry: it is not macroorganic material, it is material that has been modified from their original form over time and is material that has reach stablity. Compost is none of those things. It is inaccurate to say that compost is humus, or even to imply that composting is humification. Why would you even want to say that? If wikipedia says any different (and I've no idea whether it does or not, because I haven't looked at wikipedia) is irrelevant. If it claims that composting is humification, it is wrong.

3. You made several errors when talking about green manure which made it very difficult to unravel what was true from what was not true. As I said above (and I believe Chris already said), green material is not green manure. Green manures have technical meanings - in agriculture a green manure is a growing crop which may be grown in Winter to avoid nitrate loss and erosion and is ploughed in before replanting. It may also be green material that is added directly to soils as an amendment. We're not here talking about either of those situations. You also orginally said that green [material] is low in Nitrogen, which is not true. And you continue to repeat that composting is something which is done by soil bacteria - it is not. Please only refer to aerobic microbes, given that many other micro and macro-organisms can be involved in the process. I don't think your point about 'the whole plant' really means anything at all.

4. I agree that not everyone can use videos. However, appropedia supports videos and I think they are worth having. I am happy to hear other ideas or see some useful pictures if you have any.

5. I don't agree that we need to repeat information, I'm sorry. The purpose, as far as I am concerned, of this page is to provide an introduction to the subject of composting and a 'way in' for those who are interested to find out more detailed information. If you have a different idea about what this page is for, I'd be very interested to hear about it.

6. I don't agree that the rewrite you suggest is an improvement. Boma composting is something which is only found on google as a link to this page, from which there is no information and the section makes no sense. If you have a link explaining exactly what it is that you are talking about, maybe it needs its own page. Ditto sheet composting, which seems to be a discussion about mulching, which has a separate page on appropedia where it is explained in a better way.

The first section in the revision you suggest is imprecise, poorly written and wrong. The second section is mostly just poorly written. The third is incorrect (composting can be efficiently completed at higher C:N ratios than 35:1). The hot composting section is just wrong and potentially dangerous in that it talks of pathogen breakdown at incorrect temperatures. Cold composting section is wrong ('cold' compost is not necessarily higher in C). The pile or bin composting section repeats you unfounded assertions about layering materials. Boma compost I have already mentioned. It is hard to understand what the sheet composting section is about, and the troubleshooting section is badly written. I don't see that there is any merit in keeping any of this.

As I said above, the issue is the point of this page. As far as I am concerned, the point is to introduce novice visitors to concepts in composting, which are expanded and explained elsewhere. If this could be done by redirecting the page to the category:composting page, I think it would provide a platform for an interested person to browse around the various articles that are available. Given (some of) the relevant articles are in the footer of the category:composting page, I found myself wanting to copy and paste all of them into this page, which seemed a monumental waste of time.

Again, if you have a better/different understanding of the purpose of this page, I'd be interested to hear about it. Joeturner 06:55, 7 February 2013 (PST)

Comments on rewrite[edit source]

From a quick look, I like a lot of what you've done. As KVDP says, thanks for contributing here - and thanks for being bold about it. Clearly you've got knowledge to contribute.

The first, major edit of the rewrite involves adding a lot of content, but also taking a lot away. (I think a lot KVDP's concerns are with this.) I wasn't clear which bits you deleted because you judged they were "better presented elsewhere" (and if so, where?) and which bits you judged to just be inaccurate. In this case, a few lines of explanation of that particular edit on this talk page would be very helpful - is that possible?

A useful approach (acknowledging that being bold is usually better than being "ideal") we do major deletions section-by-section with little explanations in the edit summary.

Re "Humus takes tens, hundreds and possibly thousands of years to form in the soil." Citation needed as they say at Wikipedia :-). And, as with how that tag is used on Wikipedia, I'm not saying you're wrong. It's just not how I understood it, and I couldn't find a source for this when I looked just now.

Re the category page: "I now would like to suggest that this content (or perhaps something even simpler than this) would be better suited as an introduction to the subject on the Category:Composting and that this page is essentially pointless and might be better not to exist at all as a separate page." I'm unclear - do you mean paste this info onto the category page itself? We're actually moving away from putting a lot of content on category pages. So for category Foo, page Foo essentially serves as the introduction to the topic (with just an extremely brief definition in the {{cat header}} template on the category itself).

Re something even simpler... that implies a removal of detail from here. Would that be moved elsewhere?

Re carpets as mulch - I have no firm opinion (though I'm dubious about it if they're not biodegradeable). But if it's a known practice, my view is that it should be documented here, perhaps under Carpets as mulch, even if the conclusion of the article is "this is a bad idea." (More likely, it would be "this is a bad idea, except under conditions X, Y and Z.")

Thanks again. --Chriswaterguy 05:19, 7 February 2013 (PST)


1. It was always my intention to make changes and justify them here - this is why I made you both aware that I had made them and recorded my presence in this space. I did not believe anything other than wholesale and major changes were necessary, given that some of the information presented was actually dangerous. I think that section (regarding pathogen breakdown) can actually be improved with relevant links, but to make a sweeping statement like that is foolish, in my professional opinion. And I don't think it has any value in a general article introducing composting anyway. When we get around to discussing composting of sewage sludge, I hope we will be able to come to some kind of consensus on what is, exactly, safe for us to tell users.

2. As I suggested above, I believed there were important problems with all the original sections. I originally kept the sections intact (as far as I was able), but did not believe in the end that the original layout was logical or justified.

3. I provided a link regarding the dynamics of humus in the soil above. Other studies have given humus ages in the thousands of years. But again, this whole subject is highly complex because the breakdown of organic matter in the soil produces diffeent 'daughter' chemical structures which in turn have different impacts on the chemistry and fertility of a given soil. To describe composting as humification and to use the term humus is to imply that the products you get from a compost heap after a few months are identical to the humic fraction of the soil (and hence have the same properties). That isn't true. And is so misleading that we're better off not using those words at all in an article about compost. As far as I am concerned, dead plants decompose incompletely to compost, which further stabilises into humus in the soil over a long period of time. Compost itself has useful properties, but is not chemically the same as humus.

4. I explained a little of my thinking regarding removal of this page. I believe that it would be better if redirected to the composting category and that the content was an introduction to the subject, with a range of pages below as links for futher information. We could then expand individual pages about C/N ratios and anything else we wanted. It seems to me that the introduction would then be better as a basic glossary explaining terms used rather than an attempt to explain the whole thing. Alternatively, we need to supply a lot of links below this page for further reading.

5. I agree about carpet. I'm happy to argue about it on a relevant page, but I maintain it has almost nothing to do with composting anyway. I think we need to stick to subjects which are undoubtedly about composting here. Other pages of relevance could be listed in the related links. Joeturner 07:20, 7 February 2013 (PST)

Thanks. Re your replies to myself and KVDP - I won't comment in detail as I have some deadlines, and want to avoid getting drawn too much further into this very interesting vortex right now :-).
A few Wikipedia practices are helpful to consider here.
  • It can be helpful when removing content to remove it to the talk page. In this case it deserves its own subpage - I've gone and done this at Talk:Composting/removed 2013-02. That can make it much easier to see what's been done and ask about specific deletions - otherwise it's hard to join the conversation without spending ages catching up.
  • Repeating content: I think Wikipedia has a good model, where a subtopic (e.g. "bin composting") has a section in the main article, with a summary and a link to the more specific article on that topic - the {{main}} template is appropriate (use: {{main}}), or {{see also}} if the layout is a bit different.
  • Humification: Unless there is some justification (with sources) for the idea that compost=humus or composting=humification, let's all accept that those ideas are not going in the article. No need to spend more time on this.
  • Videos: I agree, these can be great (assuming they're carefully chosen... we'll need to develop a process for this on Appropedia). Some people can't access videos, sure - the solution is to improve the page together so that those people who can't or won't watch video aren't missing out.
Cheers --Chriswaterguy 16:38, 7 February 2013 (PST)
Good points well made regarding the subpage. I have added a second subpage with comments on the page as of Nov 2012. Joeturner 01:34, 8 February 2013 (PST)

KVDP brings back inaccurate information[edit source]

All content returned despite considerable effort discussing the changes above. Have removed inaccurate information and recommended daughter pages are removed as they are unnecessary. Happy to have a debate about the changes, not happy to be totally ignored. Joeturner 09:56, 13 March 2013 (PDT)

Hi Joe, I did some major updates to the page as I now had some time, and wish to resolve the issues I had with your rewrite until I tackle any new projects here (I'm looking forward on making new schematics on a DIY ventilation system and other designs, shown in a new book I obtained). I didn't at all ignore you, if I did this then I would have just reverted the page to my old version. Rather than this, I took account of your objections/changes and my objections to the current rewrite and made the page a compromise. Anyway the changes I did:

I first printed out my old version of the article and your new edit, put them side by side and started analysing this, aswell as a printed out copy of your suggestions at the talk page.

First of all, I changed the intro text reintegrating some of the text of my old page, but implementing your statements on humus vs compost. I removed your term "stable compost" and changed it with "compost" as I find we better use this term to differentiate organic matter (any organic matter), green manure (whole plants) from compost. I described compost as being a intermediate step towards humus. At the Humus page, I changed the page and clarified that this is compost that has decomposed for hundreds of years.

Then for the fact that you wanted this to be an introduction page. As Chris said, pages like this allready work as an introduction for the category. So, I deleted the "introduction to ..." headline as it is redundant. However, I did split it up into several pages now so most of the removed text is now at different pages, shrinking down the page in the process.

Then for the video's: Chris stated last time that video's weren't a big issue, but I actually disagree. the thing isn't that some people may simply not be capable of viewing the video's, but rather that when they are integrated at all, they reduce the loading time of the page considerably, even if they can't view them. As Mr. Weir of CD3WD stated, people in developing countries (and even I with my crappy PC) encounter great hinder from "heavy pages". So, I think that we should put these video's (if at all) on pages that are less read (this is a heavily read/important page). The same btw goes for those annoying Google maps (see Permaculture#Permaculture_map; this was btw the reason why I put the map down at the bottom with my rewrite of this, when it's at the bottom people don't need to move the page to there, so that makes it less heavy for the PC)

KVDP 10:01, 13 March 2013 (PDT)

I have few issues with Composting as you've edited, but the information on the other pages is not correct. I don't care either way about the vids, but they're not appropriate for the PA page. Joeturner 10:03, 13 March 2013 (PDT)
I'm not at present arguing about your edits of Composting, although you should never ever advise anyone to compost meat. But you have attempted to replace some of the most erroneous material from the page (and discussed above) in new pages. Joeturner 10:11, 13 March 2013 (PDT)
For the video's: you can place them at any other less-frequently viewed page if you wish or remove them.
Well I think we should investigate what other people think about videos. I don't think we should just remove things because you happen not to like them. I happen to think that good videos are worth having. Joeturner 13:19, 13 March 2013 (PDT)
As stated above, I'm not the only one that is concerned about the huge bandwith/processing power requirements the pages require due to the video's; Alex Weir of CD3WD was also concerned about this and even went to far greater lengths (not using wiki's at all). I see the value of video's , I just think that they don't fit in a popular page like this

KVDP 05:35, 16 March 2013 (PDT)

Lonny on VP and now Chris (below) have underlined that video embeds are not only allowed on Appropedia, they are encouraged. They are on more than 100 pages. If you have a problem with that, talk to them about it. Joeturner 08:29, 17 March 2013 (PDT)
I saw what you mean about the erroneous material at You can make the seperate pages (Composting in practice, hot composting, cold composting, pile composting, ...) more accurate as you are allready doing. Just try to keep the sentences/lay out, and just correct all the info in it. KVDP 10:32, 13 March 2013 (PDT)
I will not be adding anything to these pages and have recommended them for deletion. They add nothing and they are the wrong pages. The subject needs expansion, but not like that. Joeturner 13:15, 13 March 2013 (PDT)
Fine, let's then talk about how you want to do it at the talk page before you work on it. I sense some hostility here due to my recent edits but really I think I cooperate with you on improving the page. At the time I first started editing at ie Wikipedia, people were far less patient with me. I don't stop you from editing the page and making it more accurate, I just want it to be done in a manner we both agree on.
I don't really feel that there is anything much to talk about - at present I have been simply undoing information, largely from you, that is technically wrong. I have done this once on this page (and explained in detail what I did) and then I did it again with other pages. You don't know about composting. Either justify what you are writing with sources, or stick to subjects you know something about. I'm not negotiating with you, because you clearly don't know what you are talking about. If you put any kind of content that I have deleted back, anywhere on Appropedia, I will delete it, because it is wrong. I am happy to discuss things you've read and the science behind any of the deletions I have made. So the onus it totally on you to ensure you put things here which can be justified. If they can't, I will remove them. On the other hand, I have made very minor edits in things to do with your language. I am not a language expert and agree the page could read better. I reserve the right to remove things which are just wrong. Joeturner 08:29, 17 March 2013 (PDT)
I must say that I don't really find you a team player; your statement that I don't know "anything" about composting underscores this. The fact that you are a soil scientist (of which I btw still don't have proof -no reference- but which I'm inclined to believe) also doesn't give you a free pass to just write down anything. I remember you mentioned some things were not a good technique ie trench composting; however we are not looking at things from a scientists perspective; AT is about practical methods -not always completely efficient but rather cheap and easy- to handle a problem. Also, please bear in mind that I didn't wrote the whole article, there may be mistakes in there and I'm also not going to defend these; rather I had a problem with the fact that you destroyed the entire layout of the pages, ... BTW: english isn't "my language", I'm Dutch. Anyway, I'll go over the printed pages once more and see what I don't agree on and later correct this.KVDP 05:55, 21 March 2013 (PDT)
I don't care what you do, but if it is wrong, I will remove it. I have two degrees in Soil Science and practical experience of working in large scale composting of sewage sludge as as consultant scientist. I don't have a free pass, but I do have the ability to tell when what is written is wrong and/or dangerous within my circle of expertise. Your edits are wrong. If you want them to stay, supply some evidence. The layout was rubbish and unusable as a primer for composting, the content was worse. Please do not add anything else to any pages about composting. Joeturner 06:18, 21 March 2013 (PDT)

Also, I think that your energy is best spend on improving articles that have not yet been edited much or which still need to be created. More gain is to be made here. For example the articles on farming equipment (make many new articles, ie on cultivators, rototillers, rollers and cultipackers, look into the optimal temperature of septic tanks and composting toilets and mention in those articles,, make an article on solarization (soil technique), covering roots with earth or wooden barrels (soil technique; used with rhubarb, chicory, Scorzonera, asparagus, ...)
And I think it best that you stick to things you actually know something about. And stop telling me the things that I should do on Appropedia when you clearly have no idea where my expertise lies. Joeturner 06:18, 21 March 2013 (PDT)
Re composting meat: this is organic material too and needs some way to be processed. I actually advocate using anaerobic digestion myself (Bokashi composting, ...). I just briefly mentioned it here for people that don't have such a system (I think that's still better than throwing it in a dust bin/garbage bag).KVDP 10:35, 13 March 2013 (PDT)
We should not be recommending anyone composts meat, end of story. Dangerous and silly thing for anyone to recommend. Joeturner 13:15, 13 March 2013 (PDT)
In the book I'm reading, I just read that putting cooked fish/meat in a Bokashi composter is a correct way of handling this organic waste. Clearly it isn't a "dangerous and silly" thing to do. I also believe you don't have much experience with waste disposal in developing countries based on this sort of reply. Have you ever seen waste disposal being conducted in these countries ?

KVDP 05:55, 21 March 2013 (PDT)

Bokashi is not aerobic composting. Therefore it is irrelevant. Joeturner 06:18, 21 March 2013 (PDT)

Videos[edit source]

KVDP, if you have a problem with video embeds, you need to talk to talk to Lonny. If you have a problem with the content of these videos, you can talk to me. You can't just delete things because you don't happen to like the format. Joeturner 01:47, 14 March 2013 (PDT)

We don't have a policy of restricting use of videos, so bandwidth isn't a reason for deleting them. The bandwidth doesn't stop anyone accessing the rest of the page - they don't need to play the videos.
I'd like us to have a general understanding to put all the key info in text and modest-sized images, so that the videos are a nice extra. That means that if a page is lacking, it can be rectified by adding text rather than by removing the video. It's best for the videos to not be put at the very top - so those of us who can't (or don't want to) watch the video can see that there's text/images.
i see no problem with the videos here, and I agree that unilaterally removing a certain type of content must be avoided. Thanks. --Chriswaterguy 04:33, 17 March 2013 (PDT)

Other pages on aspects of composting[edit source]

I am aware that some of this page can and should be expanded, but the changes you made, KVDP were inaccurate, unhelpful, needlessly (and wrongly) precise and made the readability worse. I have therefore reverted them. If you add similar material again, I will delete it. If you add other material on the subject which has no source, I will delete that as well. Joeturner 08:40, 11 April 2013 (PDT)

Merge[edit source]

I have ported the composting page from to Composting (PIW). That page should be merged into this page. --Ethan (talk) 18:28, 13 August 2015 (PDT)

And another: Compost (PermaWiki) --Ethan (talk) 07:19, 17 October 2015 (PDT)
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