Compost

Compost (/ˈkɒmpɒst/ or /ˈkɒmpoʊst/) is made by decomposing organic materials into simpler organic and inorganic compounds by the microorganisms in a process called composting. This process recycles various organic materials otherwise regarded as waste products. A good compost is rich in plant nutrients and beneficial organisms.

Not to be confused with compositing.

Community-level composting in a rural area in Germany
Backyard composter

Compost is used to improve the soil fertility in gardens, landscaping, horticulture, urban agriculture and organic farming. The compost is beneficial by providing nutrients as fertilizer to the crop, acting as soil conditioner, increasing the humus or humic acids content of the soil, and most important action of introducing beneficial colonies of microbes in the soil. The natural interaction of the soil, plant roots and nutrient / microorganisms of compost, improves the soil structure. An improved soil structure will increase the soil water retention ability and control soil erosion. Compost can result in land and stream reclamation and ecofriendly wetland construction. As a landfill cover, compost provides a healthy utilization of waste organic materials.

At its simplest level, composting requires gathering a mix of 'Greens' and 'Browns'. Greens are materials rich in nitrogen such as leaves, grass, and food scraps and browns are more woody materials rich in carbon-like stalks, paper and wood chips. The materials are wetted to start them breaking down into humus, a process that occurs over a period of months. Most organic standards demand at least a 60 days composting process, however, composting can also take place as a multi-step, closely monitored process with measured inputs of water, air, and carbon- and nitrogen-rich materials. The decomposition process is aided by shredding the plant matter, adding water, and ensuring proper aeration by regularly turning the mixture when open piles or "windrows" are used. Fungi, earthworms and other detritivores further break up the organic material. Aerobic bacteria and fungi manage the chemical process by converting the inputs into heat, carbon dioxide, and ammonium.

Fundamentals
Home compost barrel
Materials in a compost pile
Food scraps compost heap

Composting is an aerobic method (meaning that it requires the presence of air) of decomposing organic solid wastes.[1] It can therefore be used to recycle organic material. The process involves decomposition of organic material into a humus-like material, known as compost, which is a good fertilizer for plants.

Composting organisms require four equally important ingredients to work effectively:

  • Carbon — for energy; the microbial oxidation of carbon produces the heat, if included at suggested levels.[2] 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.
  • Oxygen — for oxidizing the carbon, the decomposition process.
  • Water — in the right amounts to maintain activity without causing anaerobic conditions.[3]

Certain ratios of these materials will provide microorganisms to work at a rate that will heat up the compost pile. Active management of the pile (e.g., turning) is needed to maintain sufficient supply of oxygen and the right moisture level. The air/water balance is critical to maintaining high temperatures 130–160 °F (54–71 °C) until the materials are broken down.[4]

The most efficient composting occurs with an optimal carbon:nitrogen ratio of about 25:1.[5] Hot container composting focuses on retaining heat in order to increase the decomposition rate thus producing compost more quickly. Rapid composting is favored by having a C/N ratio of ~30 or less. Above 30 the substrate is nitrogen starved. Below 15 it is likely to outgas a portion of nitrogen as ammonia.[6]

Nearly all dead plant and animal materials have both carbon and nitrogen, but amounts vary widely, with characteristics noted above (dry/wet, brown/green).[7] Fresh grass clippings have an average ratio of about 15:1 and dry autumn leaves about 50:1 depending upon species. Mixing equal parts by volume approximates the ideal C:N range. Few individual situations will provide the ideal mix of materials at any point. Observation of amounts, and consideration of different materials as the compost pile is built up over time, can quickly achieve a workable technique for the individual situation.

Microorganisms

With the proper mixture of water, oxygen, carbon, and nitrogen, microorganisms are able to break down organic matter to produce compost.[8][9] The composting process is dependent on microorganisms to break down organic matter into compost. There are many types of microorganisms found in active compost of which the most common are:[10]

  • Bacteria- The most numerous of all the microorganisms found in compost. Depending on the phase of composting, mesophilic or thermophilic bacteria may predominate.
  • Actinobacteria- Necessary for breaking down paper products such as newspaper, bark, etc.
  • Fungi- molds and yeast help break down materials that bacteria cannot, especially 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.

Phases of composting
Three year old household compost

Under ideal conditions, composting proceeds through three major phases:[10]

  • Mesophilic phase: An initial, mesophilic phase, in which the decomposition is carried out under moderate temperatures by mesophilic microorganisms.
  • Thermophilic phase: As the temperature rises, a second, thermophilic phase starts, in which the decomposition is carried out by various thermophilic bacteria under higher temperatures (50 to 60 °C (122 to 140 °F).)
  • Maturation phase: As the supply of high-energy compounds dwindles, the temperature starts to decrease, and the mesophiles once again predominate in the maturation phase.

Hot and cold composting - impact on timing

The time required to compost material relates to the volume of material, the size of the inputs (eg. wood chips break down faster than branches) and the amount of mixing or aeration - usually by turning the pile. Generally, larger piles will reach higher temperatures and remain in a thermophilic stage for days or weeks. This is referred to as hot composting and is the normal method for large-scale (eg. municipal) composting facilities and many agricultural operations.

A process often referred to as the 'Berkeley method' produces finished compost in eighteen days, but it requires the assembly of a least a cubic meter of material at the outset, and requires turning every two days after a four-day initial phase.[11] Many such short processes involve a few changes to traditional methods, including smaller, more homogenized pieces in the compost, controlling carbon-to-nitrogen ratio (C:N) at 30 to 1 or less, and monitoring the moisture level more carefully.

Cold composting is a slower process that can take up to a year to complete.[12] It results from smaller piles, including many residential compost piles that receive small amounts of kitchen and garden waster over extended periods. Piles smaller than approximately a cubic meter have trouble reaching and maintaining high temperature.[13] Turning is not necessary with cold composting, however, there is a risk that parts of the pile may go anaerobic as they get compacted or water-logged.

Pathogen removal

Composting can destroy some pathogens or unwanted seeds, those that are destroyed by temperatures above 50 °C (122 °F).[14]

Materials that can be composted

Potential sources of compostable materials, or feedstocks, include residential, agricultural and commercial waste streams. There is not a linear relationship between the source of a given feedstock and the method that it is composted. For example, residential food or yard waste can be composted at home, or collected for inclusion in a large-scale municipal composting facility. In some regions, it could also be included in a local or neighborhood composting project. [15]

Organic solid waste
Main article: Biodegradable waste
A large compost pile that is steaming with the heat generated by thermophilic microorganisms.

There are two broad categories of organic solid waste: green waste and brown waste. Green waste is generally considered a source of nitrogen and includes pre- and post-consumer food waste, grass clippings, garden trimmings and fresh leaves. Animal carcasses, roadkill and butcher residue can also be composted and these are considered nitrogen sources. [16] Brown waste is a carbon source and typical examples are dried vegetation and woody material such as fallen leaves, straw, woodchips, limbs, logs, pine needles, sawdust and wood ash (not charcoal ash).[17] Products derived from wood such as paper and plain cardboard are also considered carbon sources.

Food waste can be an important feedstock depending on the region. For example, residential food waste is collected as a separate waste stream in some municipalities, and will then be included in large municipal recycling facilities. In other areas, food waste may be part of the regular waste stream and the only option for composting will be backyard or community programs. [18]

Animal manure and bedding

On many farms, the basic composting ingredients are animal manure generated on the farm as a nitrogen source, and bedding as the carbon source. 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.[19]

Human excreta
Further information: Reuse of excreta

Human excreta can be added as an input to the composting process since it is a nitrogen-rich organic material. It can be either composted directly in composting toilets, or indirectly in the form of sewage sludge after it has undergone treatment in a sewage treatment plant. Both processes require capable design as there are potential health risks that need to be managed. In the case of home composting, a wide range of microorganisms including bacteria, viruses and parasitic worms can be present in feces, and improper processing can pose significant health risks.[20] In the case of large sewage treatment facilities that collect wastewater from a range of residential, commercial and industrial sources, there are additional considerations. The composted sewage sludge, referred to as biosolids, can be contaminated with a variety of metals and pharmaceutical compounds.[21][22] Insufficient processing of biosolids can also lead to problems when the material is applied to land.[23]

Urine can be put on compost piles or directly used as fertilizer.[24] Adding urine to compost can increase temperatures and therefore increase its ability to destroy pathogens and unwanted seeds. Unlike feces, urine does not attract disease-spreading flies (such as houseflies or blowflies), and it does not contain the most hardy of pathogens, such as parasitic worm eggs.

Uses
Main article: Uses of compost

Compost can be used 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 as absorbent material (porous). This material contains moisture and soluble minerals, which provides support and nutrients. Although it is rarely used alone, plants can flourish from mixed 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.[25]

Generally, direct seeding into a compost is not recommended due to the speed with which it may dry and the possible presence of phytotoxins in immature compost that may inhibit germination,[26][27][28] and the possible tie up of nitrogen by incompletely decomposed lignin.[29] It is very common to see blends of 20–30% compost used for transplanting seedlings at cotyledon stage or later.

Compost can be used to increase plant immunity to diseases and pests.[30]

Commercial sale

The term "compost" can also refer to potting mixes which are bagged up and sold commercially in garden centers and other outlets.[31] This may include composted materials such as manure and peat, but is also likely to contain loam, fertilizers, sand, grit, etc. Varieties include multi-purpose composts designed for most aspects of planting, John Innes formulations,[31] growbags, designed to have crops such as tomatoes directly planted into them. There are also a range of specialist composts available, e.g. for vegetables, orchids, houseplants, hanging baskets, roses, ericaceous plants, seedlings, potting on etc.

Regulations
Further information: Uses of compost § Regulation and voluntary standards

There are process and product guidelines in Europe that date to the early 1980s (Germany, the Netherlands, Switzerland) and only more recently in the UK and the US. In both these countries, private trade associations within the industry have established loose standards, some say as a stop-gap measure to discourage independent government agencies from establishing tougher consumer-friendly standards.[32]

The USA is the only Western country that does not distinguish sludge-source compost from green-composts, and by default 50% of US states expect composts to comply in some manner with the federal EPA 503 rule promulgated in 1984 for sludge products.[33]

Compost is regulated in Canada[34] and Australia[35] as well.

Many countries such as Wales[36][37] and some individual cities such as Seattle and San Francisco require food and yard waste to be sorted for composting (San Francisco Mandatory Recycling and Composting Ordinance).[38][39]

Composting technologies

Various approaches have been developed to handle various ingredients, locations, throughput and applications for the composted product.

Composting is a process for converting decomposable organic materials into useful stable products, therefore, valuable landfill space can be used for other wastes by composting these materials rather than dumping them on landfills. It may however be difficult to control inert and plastics contamination from municipal solid waste.

Co-composting is a technique that processes organic solid waste together with other input materials such as dewatered fecal sludge or sewage sludge.[5]

Industrial composting systems are being installed to treat organic solid waste and recycle it rather than landfilling it. It is one example of an advanced waste processing system. Mechanical sorting of mixed waste streams combined with anaerobic digestion or in-vessel composting is called mechanical biological treatment. It is increasingly being used in developed countries due to regulations controlling the amount of organic matter allowed in landfills. Treating biodegradable waste before it enters a landfill reduces global warming from fugitive methane; untreated waste breaks down anaerobically in a landfill, producing landfill gas that contains methane, a potent greenhouse gas.

Industrial-scale

Industrial-scale composting can be carried out in the form of in-vessel composting, aerated static pile composting, vermicomposting, or windrow composting.[40]

Examples

Large-scale composting systems are used by many urban areas around the world.

Vermicomposting
Worms in a bin being harvested
This section is an excerpt from Vermicompost[edit]
Vermicomposting uses worms to decompose waste and make nutrient-rich "worm manure".

Vermicompost (vermi-compost) is the product of the decomposition process using various species of worms, usually red wigglers, white worms, and other earthworms, to create a mixture of decomposing vegetable or food waste, bedding materials, and vermicast. This process is called vermicomposting, while the rearing of worms for this purpose is called vermiculture.

Vermicast (also called worm castings, worm humus, worm manure, or worm faeces) is the end-product of the breakdown of organic matter by earthworms.[42] These castings have been shown to contain reduced levels of contaminants and a higher saturation of nutrients than the organic materials before vermicomposting.[43]

Vermicompost contains water-soluble nutrients and is an excellent, nutrient-rich organic fertilizer and soil conditioner.[44] It is used in farming and small scale sustainable, organic farming.

Black soldier fly larvae
Main article: Hermetia illucens § Uses in composting or as food for animals

Black soldier fly (Hermetia illucens) larvae are able to rapidly consume large amounts of organic material when kept at around 30 °C.[45][46] Black soldier fly larvae can reduce the dry matter of the organic waste by 73% and convert 16–22% of the dry matter in the waste to biomass.[47][48] The resulting compost still contains nutrients and can be used for biogas production, or further traditional composting or vermicomposting[49] The larvae are rich in fat and protein, and can be used as, for example, animal feed or biodiesel production.[50] Enthusiasts have experimented with a large number of different waste products.[51]

Bokashi
This section is an excerpt from Bokashi (horticulture)[edit]
A soil ball with indigenous worms in soil amended a few weeks previously with bokashi fermented matter.

Bokashi is a process that converts food waste and similar organic matter into a soil amendment which adds nutrients and improves soil texture. It differs from traditional composting methods in several respects. The most important are:

  • The input matter is fermented by specialist bacteria, not decomposed.
  • The fermented matter is fed directly to field or garden soil, without requiring further time to mature.
  • As a result, virtually all input carbon, energy and nutrients enter the soil food web, having been neither emitted in greenhouse gases and heat nor leached out.
Other names attributed to this process include bokashi composting, bokashi fermentation and fermented composting.

Hügelkultur (raised garden beds or mounds)
An almost completed Hügelkultur bed; the bed does not have soil on it yet.
Main article: Hügelkultur

The practice of making raised garden beds or mounds filled with rotting wood is also called hügelkultur in German.[52][53] It is in effect creating a nurse log that is covered with soil.

Benefits of hügelkultur garden beds include water retention and warming of soil.[52][54] Buried wood acts like a sponge as it decomposes, able to capture water and store it for later use by crops planted on top of the hügelkultur bed.[52][55]

Compost tea

Compost teas are defined as water extracts leached from composted materials.[56] Compost teas are generally produced from adding one volume of compost to 4–10 volumes of water, but there has also been debate about the benefits of aerating the mixture.[56] Field studies have shown the benefits of adding compost teas to crops due to the adding of organic matter, increased nutrient availability and increased microbial activity.[56] They have also been shown to have an effect on plant pathogens.[57]

Composting toilets
This section is an excerpt from Composting toilet[edit]
Composting toilet at Activism Festival 2010 in the mountains outside Jerusalem

A composting toilet is a type of dry toilet that treats human waste by a biological process called composting. This process leads to the decomposition of organic matter and turns human waste into compost-like material, but does not destroy all pathogens. Composting is carried out by microorganisms (mainly bacteria and fungi) under controlled aerobic conditions.[58] Most composting toilets use no water for flushing and are therefore called "dry toilets".

In many composting toilet designs, a carbon additive such as sawdust, coconut coir, or peat moss is added after each use. This practice creates air pockets in the human waste to promote aerobic decomposition. This also improves the carbon-to-nitrogen ratio and reduces potential odor. Most composting toilet systems rely on mesophilic composting. Longer retention time in the composting chamber also facilitates pathogen die-off. The end product can also be moved to a secondary system – usually another composting step – to allow more time for mesophilic composting to further reduce pathogens.

Composting toilets, together with the secondary composting step, produce a humus-like endproduct that can be used to enrich soil if local regulations allow this. Some composting toilets have urine diversion systems in the toilet bowl to collect the urine separately and control excess moisture. A vermifilter toilet is a composting toilet with flushing water where earthworms are used to promote decomposition to compost.

Organic ingredients intended for composting can also be used to generate biogas through anaerobic digestion. This process stabilizes organic material. The residual material, sometimes in combination with sewage sludge can be treated by a composting process before selling or giving away the compost.[59]

History
Compost Basket

Composting as a recognized practice dates to at least the early Roman Empire, and was mentioned as early as Cato the Elder's 160 BCE piece De Agri Cultura.[60] Traditionally, composting involved piling 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.[61] The first industrial station for the transformation of urban organic materials into compost was set up in Wels, Austria in the year 1921.[62] Early frequent citations for propounding composting within farming are for the German-speaking world Rudolf Steiner, founder of a farming method called biodynamics, and Annie Francé-Harrar, who was appointed on behalf of the government in Mexico and supported the country 1950–1958 to set up a large humus organization in the fight against erosion and soil degradation.[63]

In the English-speaking world it was Sir Albert Howard who worked extensively in India on sustainable practices and Lady Eve Balfour who was a huge proponent of composting. Composting was imported to America by various followers of these early European movements by the likes of 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-the-land movement of the 1960s). Coincidentally, some of the above met briefly in India – all were quite influential in the U.S. from the 1960s into the 1980s.

See also

References
  1. Masters, Gilbert M. (1997). Introduction to Environmental Engineering and Science. Prentice Hall. ISBN 9780131553842.
  2. "Composting for the Homeowner - University of Illinois Extension". Web.extension.illinois.edu. Archived from the original on 24 February 2016. Retrieved 18 July 2013.
  3. "Composting for the Homeowner -Materials for Composting". uiuc.edu. Archived from the original on 25 December 2009. Retrieved 13 April 2010.
  4. Lal, Rattan (30 November 2003). "Composting". Pollution a to Z. 1.
  5. Tilley, Elizabeth; Ulrich, Lukas; Lüthi, Christoph; Reymond, Philippe; Zurbrügg, Chris (2014). "Septic tanks". Compendium of Sanitation Systems and Technologies (2nd ed.). Duebendorf, Switzerland: Swiss Federal Institute of Aquatic Science and Technology (Eawag). ISBN 978-3-906484-57-0.
  6. Haug, Roger (1993). The Practical Handbook of Compost Engineering. CRC Press. ISBN 9780873713733.
  7. Klickitat County WA, USA Compost Mix Calculator Archived 17 November 2011 at the Wayback Machine
  8. "Chapter 1, The Decomposition Process". aggie-horticulture.tamu.edu. Retrieved 11 July 2016.
  9. "How to Make Compost at Home". asthegardenturns.com. Retrieved 11 July 2016.
  10. "Composting - Compost Microorganisms". Cornell University. Retrieved 6 October 2010.
  11. "The Rapid Compost Method by Robert Raabe, Professor of Plant Pathology, Berkeley" (PDF). Retrieved 21 December 2017.
  12. "Composting" (PDF). USDA Natural Resources Conservation Service. April 1998. Retrieved 30 December 2020.
  13. "Home Composting" (PDF). Cornell Waste Management Institute. 2005. Retrieved 30 December 2020.
  14. Robert, Graves (February 2000). "Composting" (PDF). Environmental Engineering National Engineering Handbook. p. 2-22.
  15. Nierenberg, Amelia (9 August 2020). "Composting Has Been Scrapped. These New Yorkers Picked Up the Slack". New York Times. Retrieved 17 November 2020.
  16. "Natural Rendering: Composting Livestock Mortality and Butcher Waste" (PDF). Cornell Waste Management Institute. 2002. Retrieved 17 November 2020.
  17. Rishell, Ed (2013). "Backyard Composting" (PDF). Virginia Cooperative Extension. Virginia Polytechnic Institute and State University. Archived from the original (PDF) on 17 November 2020. Retrieved 17 November 2020.
  18. "STA Feedstocks". U.S. Composting Council.
  19. Dougherty, Mark. (1999). Field Guide to On-Farm Composting. Ithaca, New York: Natural Resource, Agriculture, and Engineering Service.
  20. Domingo, J. L.; Nadal, M. (August 2012). "Domestic waste composting facilities: a review of human health risks". Environment International. 35 (2): 382–9. doi:10.1016/j.envint.2008.07.004. PMID 18701167.
  21. Kinney, Chad A.; Furlong, Edward T.; Zaugg, Steven D.; Burkhardt, Mark R.; Werner, Stephen L.; Cahill, Jeffery D.; Jorgensen, Gretchen R. (December 2006). "Survey of Organic Wastewater Contaminants in Biosolids Destined for Land Application †". Environmental Science & Technology. 40 (23): 7207–7215. doi:10.1021/es0603406. Retrieved 2 January 2021.
  22. Morera, M T; Echeverría, J.; Garrido, J. (1 November 2002). "Bioavailability of heavy metals in soils amended with sewage sludge". Canadian Journal of Soil Science. 82 (4): 433–438. doi:10.4141/S01-072. hdl:2454/10748. Retrieved 2 January 2021.
  23. "'Humanure' dumping sickens homeowner". Renfrew Mercury. 13 October 2011. Archived from the original on 10 November 2015. Retrieved 2 January 2021.
  24. "Stockholm Environment Institute - EcoSanRes - Guidelines on the Use of Urine and Feces in Crop Production" (PDF). Archived from the original (PDF) on 30 December 2010. Retrieved 14 July 2010.
  25. EPA,OSWER,ORCR, US (16 April 2013). "Reduce, Reuse, Recycle - US EPA" (PDF). US EPA. Retrieved 21 December 2017.CS1 maint: multiple names: authors list (link)
  26. Morel, P.; Guillemain, G. (2004). "Assessment of the possible phytotoxicity of a substrate using an easy and representative biotest". Acta Horticulturae (644): 417–423. doi:10.17660/ActaHortic.2004.644.55.
  27. Itävaara et al. Compost maturity - problems associated with testing. in Proceedings of Composting. Innsbruck Austria 18-21.10.2000
  28. Aslam DN, et al. (2008). "Development of models for predicting carbon mineralization and associated phytotoxicity in compost-amended soil". Bioresour Technol. 99 (18): 8735–8741. doi:10.1016/j.biortech.2008.04.074. PMID 18585031.
  29. "The Effect of Lignin on Biodegradability - Cornell Composting". cornell.edu.
  30. Bahramisharif, Amirhossein; Rose, Laura E. (2019). "Efficacy of biological agents and compost on growth and resistance of tomatoes to late blight". Planta. 249 (3): 799–813. doi:10.1007/s00425-018-3035-2. ISSN 1432-2048. PMID 30406411.
  31. "John Innes potting compost". Royal Horticultural Society. Retrieved 7 August 2020.
  32. "US Composting Council". Compostingcouncil.org. Retrieved 18 July 2013.
  33. "Electronic Code of Federal Regulations. Title 40, part 503. Standards for the use or disposal of sewage sludge". U.S. Government Printing Office. 1998. Retrieved 30 March 2009.
  34. "Canadian Council of Ministers of the Environment - Guidelines for Compost Quality" (PDF). CCME Documents. 2005. Archived from the original (PDF) on 18 October 2015. Retrieved 4 September 2017.
  35. "Organics Recycling in Australia". BioCycle. 2011. Retrieved 4 September 2017.
  36. "Gwynedd Council food recycling". Archived from the original on 1 May 2014. Retrieved 21 December 2017.
  37. "Anglesey households achieve 100% food waste recycling". edie.net.
  38. "Recycling & Composting in San Francisco - Frequently Asked Questions". San Francisco Dept. of the Environment. 2016. Retrieved 4 September 2017.
  39. Tyler, Aubin (21 March 2010). "The case for mandatory composting". The Boston Globe. Retrieved 19 September 2010.
  40. US EPA, OLEM (19 August 2015). "Types of Composting and Understanding the Process". US EPA. Retrieved 16 October 2020.
  41. 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
  42. "Paper on Invasive European Worms". Retrieved 22 February 2009.
  43. Ndegwa, P.M.; Thompson, S.A.; Das, K.C. (1998). "Effects of stocking density and feeding rate on vermicomposting of biosolids" (PDF). Bioresource Technology. 71: 5–12. doi:10.1016/S0960-8524(99)00055-3.
  44. 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.
  45. Diener, Stefan; Studt Solano, Nandayure M.; Roa Gutiérrez, Floria; Zurbrügg, Christian; Tockner, Klement (2011). "Biological Treatment of Municipal Organic Waste using Black Soldier Fly Larvae". Waste and Biomass Valorization. 2 (4): 357–363. doi:10.1007/s12649-011-9079-1. ISSN 1877-2641.
  46. Booth, Donald C.; Sheppard, Craig (1 April 1984). "Oviposition of the Black Soldier Fly, Hermetia illucens (Diptera: Stratiomyidae): Eggs, Masses, Timing, and Site Characteristics". Environmental Entomology. 13 (2): 421–423. doi:10.1093/ee/13.2.421. ISSN 0046-225X.
  47. Lalander, Cecilia; Diener, Stefan; Magri, Maria Elisa; Zurbrügg, Christian; Lindström, Anders; Vinnerås, Björn (2013). "Faecal sludge management with the larvae of the black soldier fly (Hermetia illucens) — From a hygiene aspect". Science of the Total Environment. 458–460: 312–318. Bibcode:2013ScTEn.458..312L. doi:10.1016/j.scitotenv.2013.04.033. PMID 23669577.
  48. Banks, Ian J.; Gibson, Walter T.; Cameron, Mary M. (1 January 2014). "Growth rates of black soldier fly larvae fed on fresh human faeces and their implication for improving sanitation". Tropical Medicine & International Health. 19 (1): 14–22. doi:10.1111/tmi.12228. ISSN 1365-3156. PMID 24261901. S2CID 899081.
  49. Lalander, Cecilia; Nordberg, Åke; Vinnerås, Björn (2018). "A comparison in product-value potential in four treatment strategies for food waste and faeces – assessing composting, fly larvae composting and anaerobic digestion". GCB Bioenergy. 10 (2): 84–91. doi:10.1111/gcbb.12470. ISSN 1757-1707.
  50. Li, Qing; Zheng, Longyu; Cai, Hao; Garza, E.; Yu, Ziniu; Zhou, Shengde (2011). "From organic waste to biodiesel: Black soldier fly, Hermetia illucens, makes it feasible". Fuel. 90 (4): 1545–1548. doi:10.1016/j.fuel.2010.11.016.
  51. "E". Bio-Conversion of Putrescent Waste. ESR International. Archived from the original on 16 May 2016. Retrieved 17 April 2015.
  52. "hugelkultur: the ultimate raised garden beds". Richsoil.com. 27 July 2007. Retrieved 18 July 2013.
  53. "The Art and Science of Making a Hugelkultur Bed - Transforming Woody Debris into a Garden Resource Permaculture Research Institute - Permaculture Forums, Courses, Information & News". 3 August 2010. Archived from the original on 5 November 2015. Retrieved 18 July 2013.
  54. "Hugelkultur: Composting Whole Trees With Ease Permaculture Research Institute - Permaculture Forums, Courses, Information & News". 4 January 2012. Archived from the original on 28 September 2015. Retrieved 18 July 2013.
  55. Hemenway, Toby (2009). Gaia's Garden: A Guide to Home-Scale Permaculture. Chelsea Green Publishing. pp. 84–85. ISBN 978-1-60358-029-8.
  56. Gómez-Brandón, M; Vela, M; Martinez Toledo, MV; Insam, H; Domínguez, J (2015). "12: Effects of Compost and Vermiculture Teas as Organic Fertilizers". In Sinha, S; Plant, KK; Bajpai, S (eds.). Advances in Fertilizer Technology: Synthesis (Vol1). Stadium Press LLC. pp. 300–318. ISBN 978-1-62699-044-9.
  57. Santos, M; Dianez, F; Carretero, F (2011). "12: Suppressive Effects of Compost Tea on Phytopathogens". In Dubey, NK (ed.). Natural products in plant pest management. Oxfordshire, UK Cambridge, MA: CABI. pp. 242–262. ISBN 9781845936716.
  58. Tilley, E.; Ulrich, L.; Lüthi, C.; Reymond, Ph.; Zurbrügg, C. (2014). Compendium of Sanitation Systems and Technologies - (2nd Revised ed.). Swiss Federal Institute of Aquatic Science and Technology (Eawag), Duebendorf, Switzerland. p. 72. ISBN 978-3-906484-57-0.
  59. Dawson, Lj. "How Cities Are Turning Food into Fuel". POLITICO. Retrieved 28 February 2020.
  60. Cato, Marcus. "37.2; 39.1". De Agri Cultura.
  61. "History of Composting". illinois.edu. Archived from the original on 4 October 2018. Retrieved 11 July 2016.
  62. Welser Anzeiger vom 05. Januar 1921, 67. Jahrgang, Nr. 2, S. 4
  63. Laws, Bill (2014). A History of the Garden in Fifty Tools. University of Chicago Press. p. 86. ISBN 978-0226139937.
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