A homemade compost tumbler

Compost (play nitrification.

Compost can be rich in nutrients. It is used in downcycling waste organic matter.


[edit] Ingredients

Home compost barrel in the Escuela Barreales, Chile.

Composting organisms require four equally important things to work effectively:

  • Carbon — for energy; the microbial [1].
    • High carbon materials tend to be brown and dry.
  • Nitrogen — to grow and reproduce more organisms to oxidize the carbon.
    • High nitrogen materials tend to be green (or colorful, such as fruits and vegetables) and wet.[1]
  • Oxygen — for oxidizing the carbon, the decomposition process.
  • Water — in the right amounts to maintain activity without causing anaerobic conditions.

Materials in a compost pile.

Certain ratios of these materials will provide beneficial bacteria with the nutrients to work at a rate that will heat up the pile. In that process much water will be released as vapor (“steam”), and the oxygen will be quickly depleted, explaining the need to actively manage the pile. The hotter the pile gets, the more often added air and water is necessary; the air/water balance is critical to maintaining high temperatures (135°-160° Fahrenheit / 50° – 70° Celsius) until the materials are broken down. At the same time, too much air or water also slows the process, as does too much carbon (or too little nitrogen).

The most efficient composting occurs with a carbon:nitrogen mix of about 30 to 1. Nearly all plant and animal materials have both carbon and nitrogen, but amounts vary widely, with characteristics noted above (dry/wet, brown/green).[3] as a pile is built over time, can quickly achieve a workable technique for the individual situation.

[edit] Urine

People excrete far more of certain citation needed]

Urine is primarily composed of water and urea. Although metabolites of urea are nitrogen fertilizers, it is easy to over-fertilize with urine, or to utilize urine containing pharmaceutical (or other) content, creating too much ammonia for plants to absorb, acidic conditions, or other phytotoxicity.[5]

[edit] Manure and bedding

On many farms, the basic composting ingredients are manure generated on the farm and bedding. Straw and sawdust are common bedding materials. Non-traditional bedding materials are also used, including newspaper and chopped cardboard. The amount of manure composted on a livestock farm is often determined by cleaning schedules, land availability, and weather conditions. Each type of manure has its own physical, chemical, and biological characteristics. Cattle and horse manures, when mixed with bedding, possess good qualities for composting. Swine manure, which is very wet and usually not mixed with bedding material, must be mixed with straw or similar raw materials. Poultry manure also must be blended with carbonaceous materials – those low in nitrogen preferred, such as sawdust or straw.[6]

[edit] Microorganisms

With the proper mixture of water, oxygen, carbon, and nitrogen, micro-organisms are allowed to break down organic matter to produce compost.[8]

  • micro organisms found in compost.
  • bark, etc.
  • lignin in woody material.
  • Protozoa– Help consume bacteria, fungi and micro organic particulates.
  • Rotifers– Rotifers help control populations of bacteria and small protozoans.

In addition, earthworms not only ingest partly composted material, but also continually re-create aeration and drainage tunnels as they move through the compost.

A lack of a healthy micro-organism community is the main reason why composting processes are slow in landfills with environmental factors such as lack of oxygen, nutrients or water being the cause of the depleted biological community.[8]

[edit] Uses

Compost is generally recommended as an additive to soil, or other matrices such as coir and peat, as a tilth improver, supplying humus and nutrients. It provides a rich growing medium, or a porous, absorbent material that holds moisture and soluble minerals, providing the support and nutrients in which plants can flourish, although it is rarely used alone, being primarily mixed with soil, sand, grit, bark chips, vermiculite, perlite, or clay granules to produce loam. Compost can be tilled directly into the soil or growing medium to boost the level of organic matter and the overall fertility of the soil. Compost that is ready to be used as an additive is dark brown or even black with an earthy smell.[9]

Generally, direct seeding into a compost is not recommended due to the speed with which it may dry and the possible presence of cotyledon stage or later.

Composting can destroy pathogens or unwanted seeds. Unwanted living plants (or weeds) can be discouraged by covering with mulch/compost. The “microbial pesticides” in compost may include thermophiles and mesophiles, however certain composting detritivores such as black soldier fly larvae and redworms, also reduce many pathogens. Thermophilic (high-temperature) composting is well known to destroy many seeds and nearly all types of pathogens (exceptions may include prions). The sanitizing qualities of (thermophilic) composting are desirable where there is a high likelihood of pathogens, such as with manure. Applications include humanure composting or the deep litter technique.

[edit] Composting approaches

In addition to the traditional compost pile, various approaches have been developed to handle different composting processes, ingredients, locations, and applications for the composted product.

[edit] Grub composting


BSFL often appear naturally in compost bins. Without much added cost, these devices could be designed to also harvest BSFL.

[edit] Bokashi

Inside a recently started bokashi bin. The aerated base is just visible through the food scraps and bokashi bran.

Bokashi is a method that uses a mix of microorganisms to cover food waste to decrease smell. It derives from the practice of Japanese farmers centuries ago of covering food waste with rich, local soil that contained the microorganisms that would ferment the waste. After a few weeks, they would bury the waste that weeks later, would become soil.[13]

Most practitioners obtain the microorganisms from the product Effective Microorganisms (EM1),[13]

The EM are natural citation needed]

[edit] Compost tea

Compost tea is a liquid extract or a dissolved solution but not simply a suspension of compost. It is made by steeping compost in water for 3–7 days. It was discovered in Germany and became a practice to suppress foliar fungal diseases by nature of the bacterial competition, suppression, antibiosis on the leaf surface (phyllosphere). It has also been used as a fertilizer although lab tests show it is very weak in nutrients with less than 100ppm of available nitrogen and potassium. Other salts present in the tea solution are sodium, chlorides and sulfates.[15]

[edit] Hügelkultur

The practice of making raised garden beds filled with rotting wood.Nurse log, however, covered with dirt.

Benefits of hügelkultur garden beds include water retention and warming of soil.[19]

The buried decomposing wood will also give off heat, as all compost does, for several years. These effects have been used by Sepp Holzer for one to allow fruit trees to survive at otherwise inhospitable temperatures and altitudes.[17]

[edit] “Humanure”

“Humanure” is a [21]

Humanure is not sewage that has been processed by waste-treatment facilities, which may include waste from industrial and other sources; rather, it is the combination of feces and urine with paper and additional carbon material (such as sawdust). A humanure system, such as a compost toilet, does not require water or electricity, and when properly managed does not smell. A compost toilet collects human excrement which is then added to a hot compost heap together with sawdust and straw or other carbon rich materials, where pathogens are destroyed. A composting toilet processes the waste in situ. Because the term “humanure” has no authoritative definition it is subject to misuse; news reporters occasionally fail to correctly distinguish between humanure and “sewer sludge” or “biosolids”.[22]

By disposing of feces and urine through composting, the nutrients contained in them are returned to the soil. This aids in preventing leachate.

As a substitute for a flush water process, it reduces the energy consumption and, hence, water and waste water.

Humanure may be deemed safe for humans to use on crops if handled in accordance with local health regulations, and composted properly. This means that thermophilic decomposition of the humanure must heat it sufficiently to destroy harmful pathogens, or enough time must have elapsed since fresh material was added that biological activity has killed any pathogens. To be safe for crops, a curing stage is often needed to allow a second mesophilic phase to reduce potential phytotoxins.

Humanure is different from night soil, which is raw human waste spread on crops. While aiding the return of nutrients in fecal matter to the soil, it can carry and spread a number of human pathogens. Humanure kills these pathogens both by the extreme heat of the composting and the extended amount of time (1 to 2 years) that it is allowed to decompose.

[edit] Vermicompost

Rotary screen harvested worm castings


The earthworm species (or composting worms) most often used are red wigglers (Dendrobaena Veneta) could also be used. Red wigglers are recommended by most vermiculture experts, as they have some of the best appetites and breed very quickly. Users refer to European nightcrawlers by a variety of other names, including dendrobaenas, dendras, Dutch Nightcrawlers, and Belgian nightcrawlers.

Containing water-soluble nutrients, vermicompost is a nutrient-rich organic fertilizer and soil conditioner in a form that is relatively easy for plants to absorb.[27] Worm castings are sometimes used as an organic fertilizer. Because the earthworms grind and uniformly mix minerals in simple forms, plants need only minimal effort to obtain them. The worms’ digestive systems also add beneficial microbes to help create a “living” soil environment for plants.[citation needed]

Vermicompost tea in conjunction with 10% castings has been shown to cause up to a 1.7 times growth in plant mass over plants grown without.[28]

Researchers from the Pondicherry University discovered that worm composts can also be used to clean up heavy metals. The researchers found substantial reductions in heavy metals when the worms were released into the garbage and they are effective at removing lead, zinc, cadmium, copper and manganese.[29]

[edit] History

A modern compost bin constructed from plastics

Composting as a recognized practice dates to at least the early Roman Empire since Pliny the Elder (AD 23-79). Traditionally, composting was to pile organic materials until the next planting season, at which time the materials would have decayed enough to be ready for use in the soil. The advantage of this method is that little working time or effort is required from the composter and it fits in naturally with agricultural practices in temperate climates. Disadvantages (from the modern perspective) are that space is used for a whole year, some nutrients might be leached due to exposure to rainfall, and disease producing organisms and insects may not be adequately controlled.

Composting was somewhat modernized beginning in the 1920s in Europe as a tool for organic farming.J.I. Rodale (founder of Rodale Organic Gardening), E.E. Pfeiffer (who developed scientific practices in biodynamic farming), Paul Keene (founder of Walnut Acres in Pennsylvania), and Scott and Helen Nearing (who inspired the back-to-land movement of the 1960s). Coincidentally, some of these personages met briefly in India – all were quite influential in the U.S. from the 1960s into the 1980s.

There are many modern proponents of rapid composting that attempt to correct some of the perceived problems associated with traditional, slow composting. Many advocate that compost can be made in 2 to 3 weeks.[33]

In fact, both sides are right to some extent. The bacterial activity in rapid high heat methods breaks down the material to the extent that pathogens and seeds are destroyed, and the original feedstock is unrecognizable. At this stage, the compost can be used to prepare fields or other planting areas. However, most professionals recommend that the compost be given time to cure before using in a nursery for starting seeds or growing young plants. The curing time allows fungi to continue the decomposition process and eliminating phytotoxic substances.[citation needed]

Some cities such as Seattle and [35]

Kew Gardens in London has one of the biggest non-commercial compost heaps in Europe.[36]

[edit] Compost and land-filling

As concern about [41] Compost is regulated in Canada and Australia as well.

[edit] Industrial systems

A large compost pile that is steaming with the heat generated by thermophilic microorganisms.

Industrial composting systems are increasingly being installed as a waste management alternative to landfills, along with other methane, a potent greenhouse gas.

Vermicomposting, also known as vermiculture, is used for medium-scale on-site institutional composting, such as for food waste from universities and shopping malls: selected either as a more environmental choice, or to reduce the cost of commercial waste removal.[24]

Large-scale composting systems are used by many urban areas around the world. Co-composting is a technique that combines solid waste with de-watered biosolids, although difficulties controlling inert and plastics contamination from [43]

Another large MSW composter is the Lahore Composting Facility in Lahore, Pakistan, which has a capacity to convert 1,000 tonnes of municipal solid waste per day into compost. It also has a capacity to convert substantial portion of the intake into Refuse-derived fuel (RDF) materials for further combustion use in several energy consuming industries across Pakistan e.g., in cement manufacturing companies where it is used to heat up the Cement Kiln systems. This project has also been approved by the Executive Board of the United Nations Framework Convention on Climate Change (UNFCCC) for reduction of emission of methane gas into the climate and has been registered with a capacity of reducing 108,686 metric tonnes CO2 equivalent per annum.[44]

[edit] See also

[edit] References

  1. ^ Materials for composting – University of Illinois extension, retrieval date: 3/12/2009
  2. ^ Klickitat County WA, USA Compost Mix Calculator
  3. ^ Effect of lignin content on bio-availability
  4. ^ Stockholm Environment Institute – EcoSanRes – Guidelines on the Use of Urine and Feces in Crop Production
  5. ^ Pharmaceutical residures in urine and potential risks related to use as fertilzer in agriculture, Martina Winker, Doctoral dissertation, 2009
  6. ^ Dougherty, Mark. (1999). Field Guide to On-Farm Composting. Ithaca, New York: Natural Resource, Agriculture, and Engineering Service.
  7. ^ “Compost Made Simple”. Retrieved 21 October 2010.
  8. ^ Retrieved 6 October 2010.
  9. ^ Healthy Soils, Healthy Landscapes
  10. ^ Morel, P. and Guillemain, G. 2004. Assessment of the possible phytotoxicity of a substrate using an easy and representative biotest. Acta Horticulture 644:417–423
  11. ^ Itävaara et al. Compost maturity – problems associated with testing. in Proceedings of Composting. Innsbruck Austria 18-21.10.2000
  12. ^ Phytotoxicity and maturation
  13. ^ Retrieved 13 November 2012.
  14. ^ Zhang, W., Han, D. Y., Dick, W. A., Davis, K. R., and Hoitink, H. A. J. 1998. Compost and compost water extract-induced systemic acquired resistance in cucumber and Arabidopsis. Phytopathology 88:450-455.
  15. ^ Tränkner, A. 1992. Use of agricultural and municipal organic wastes to develop suppression to plant pathogens. in: Biological Control of Plant Diseases. E. C. Tjamos, G. C. Papavizas, and R. J. Cook, eds. Plenum Press, New York.
  16. ^
  17. ^
  19. ^ Hemenway, Toby (2009). Gaia’s Garden: A Guide to Home-Scale Permaculture. Chelsea Green Publishing. pp. 84-85. ISBN 978-1-60358-029-8.
  20. ^ Joseph Jenkins
  21. Retrieved April 2011.
  22. ^ Courtney Symons (13 October 2011). “‘Humanure’ dumping sickens homeowner”. YourOttawaRegion. Metroland Media Group Ltd..–humanure-dumping-sickens-homeowner. Retrieved 16 October 2011.
  23. ^ “Paper on Invasive European Worms”. Retrieved 22 February 2009.
  24. ^ Retrieved 31 January 2012.
  25. ^ “Vermicomposting: Indoor Composting with Earthworms”. Retrieved 201-06-26.
  26. ^ Lazcano, Cristina; Gómez-Brandón, María; Domínguez, Jorge (2008). “Comparison of the effectiveness of composting and vermicomposting for the biological stabilization of cattle manure”. Chemosphere 72: 1013–1019.
  27. ^ Coyne, Kelly and Erik Knutzen. The Urban Homestead: Your Guide to Self-Sufficient Living in the Heart of the City. Port Townsend: Process Self Reliance Series, 2008.
  28. ^ Web article on worm castings effects on plant growth
  29. ^ Cleaning up heavy metals using worms, International:, 2012,, retrieved 3 October 2012
  30. ^ Heckman, J. 2006. A history of organic farming: transitions from Sir Albert Howard’s War in the Soil to USDA National Organic Program. Renew. Agric. Food Syst. 21:143–150.
  31. ^ Welser Anzeiger vom 05. Januar 1921, 67. Jahrgang, Nr. 2, S. 4
  32. ^ The Rapid Compost Method by Robert Raabe, Professor of Plant Pathology, Berkeley
  33. ^
  34. ^ “San Francisco Signs Mandatory Recycling & Composting Laws”. Retrieved 19 September 2010.
  35. ^ Tyler, Aubin (21 March 2010). “The case for mandatory composting”. The Boston Globe. Retrieved 19 September 2010.
  36. ^ “Kew Compost heaps”. Kew Gardens. Retrieved 2012-08-09.
  37. ^ A Brief History of Solid Waste Management
  38. ^ “Preventing Contaminants in Home Compost Piles”. Retrieved 16 June 2012.
  39. ^ British Standards Institute Specifications FAQ
  40. ^
  41. ^ U.S. Government Printing Office. 1998. Electronic Code of Federal Regulations. Title 40, part 503. Standards for the use or disposal of sewage sludge. Available at: ecfr&tpl /ecfrbrowse/Title40/40cfr503 main 02.tpl. Retrieved 30 March 2009.
  42. ^ Edmonton composting facility
  43. ^ Keppel Seghers developing the first integrated waste management facility in the Middle East
  44. ^ Details on project design and its validation and monitoring reports are available at: Project 2778 : Composting of Organic Content of Municipal Solid Waste in Lahore

[edit] Further reading

  • Roger Tim Haug, Practical Handbook of Compost Engineering [Hardcover]. Lewis Publishers.
  • Insam, H; Riddech, N; Klammer, S (Eds.): Microbiology of Composting,Springer Verlag, Berlin New York 2002, ISBN 978-3-540-67568-6
  • Hogg, D., J. Barth, E. Favoino, M. Centemero, V. Caimi, F. Amlinger, W. Devliegher, W. Brinton., S. Antler. 2002. Comparison of compost standards within the EU, North America, and Australasia. Waste and Resources Action Programme Committee (UK)

[edit] External links


This article uses material from the Wikipedia article Compost, which is released under the Creative Commons Attribution-Share-Alike License 3.0.

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