Community-level composting in a rural area inGermany
Compost is a mixture of ingredients used as plant fertilizer and to improvesoil's physical, chemical, and biological properties. It is commonly prepared bydecomposing plant and food waste, recycling organic materials, and manure. The resulting mixture is rich in plant nutrients andbeneficial organisms, such as bacteria, protozoa, nematodes, and fungi. Compost improves soil fertility ingardens,landscaping,horticulture,urban agriculture, andorganic farming, reducing dependency on commercial chemical fertilizers.[1] The benefits of compost include providing nutrients to crops asfertilizer, acting as asoil conditioner, increasing thehumus orhumic acid contents of the soil, and introducing beneficial microbes that help to suppress pathogens in the soil and reduce soil-borne diseases.
At the simplest level, composting requires gathering a mix ofgreen waste (nitrogen-rich materials such as leaves, grass, and food scraps) andbrown waste (woody materials rich in carbon, such as stalks, paper, and wood chips).[1] The materials break down into humus in a process taking months.[2] Composting can be a multistep, closely monitored process with measured inputs of water, air, and carbon- and nitrogen-rich materials. Thedecomposition process is aided by shredding the plant matter, adding water, and ensuring proper aeration by regularly turning the mixture in a process using open piles orwindrows.[1][3]Fungi,earthworms, and otherdetritivores further break up the organic material.Aerobic bacteria and fungi manage the chemical process by converting the inputs into heat,carbon dioxide, andammonium ions.
Composter made from a hollow log
Composting is an important part of waste management, since food and other compostable materials make up about 20% of waste in landfills, and due to anaerobic conditions, these materials take longer to biodegrade in the landfill.[4][5] Composting offers an environmentally superior alternative to using organic material for landfill because composting reducesmethane emissions due to anaerobic conditions, and provides economic and environmental co-benefits.[6][7] For example, compost can also be used for land and stream reclamation, wetland construction, and landfill cover.
Home compost barrelCompost bins at theEvergreen State College organic farm in WashingtonMaterials in a compost pileFood scraps compost heap
Composting is anaerobic method of decomposing organic solid wastes,[8] so it can be used to recycle organic material. The process involves decomposing 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:[3]
Carbon is needed for energy; the microbialoxidation of carbon produces the heat required for other parts of the composting process.[3] High carbon materials tend to be brown and dry.[1][3]
Nitrogen is needed to grow and reproduce more organisms to oxidize the carbon.[3] High nitrogen materials tend to be green[1] and wet.[3] They can also include colourful fruits and vegetables.[1]
Oxygen is required for oxidizing the carbon, the decomposition process.[3] Aerobic bacteria need oxygen levels above 5% to perform the processes needed for composting.[3]
Water is necessary in the right amounts to maintain activity without causing locallyanaerobic conditions.[1][3]
Certain ratios of these materials allow microorganisms to work at a rate that will heat up the compost pile. Active management of the pile (e.g., turning over the compost heap) is needed to maintain sufficient 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.[9]
Composting is most efficient with acarbon-to-nitrogen ratio of about 25:1.[10]Hot composting focuses on retaining heat to increase the decomposition rate, thus producing compost more quickly. Rapid composting is favored by having a carbon-to-nitrogen ratio of about 30 carbon units or less. Above 30, the substrate is nitrogen starved. Below 15, it is likely to outgas a portion of nitrogen as ammonia.[11]
Nearly all dead plant and animal materials have both carbon and nitrogen in different amounts.[12] Fresh grass clippings have an average ratio of about 15:1 and dry autumn leaves about 50:1 depending upon species.[3] Composting is an ongoing and dynamic process; adding new sources of carbon and nitrogen consistently, as well as active management, is important.
Organisms can break down organic matter in compost if provided with the correct mixture of water, oxygen, carbon, and nitrogen.[3] They fall into two broad categories: chemical decomposers, which perform chemical processes on the organic waste, and physical decomposers, which process the waste into smaller pieces through methods such as grinding, tearing, chewing, and digesting.[3]
Bacteria are the most abundant and important of all themicroorganisms found in compost.[3] Bacteria process carbon and nitrogen and excrete plant-available nutrients such as nitrogen, phosphorus, and magnesium.[3] Depending on the phase of composting,mesophilic orthermophilic bacteria may be the most prominent.
Mesophilic bacteria get compost to the thermophilic stage through oxidation of organic material.[3] Afterwards they cure it, which makes the fresh compost more bioavailable for plants.[3][13]
Thermophilic bacteria do not reproduce and are not active between −5 and 25 °C (23 and 77 °F),[14] yet are found throughout soil. They activate once the mesophilic bacteria have begun to break down organic matter and increase the temperature to their optimal range.[13] They have been shown to enter soils via rainwater.[13] They are present so broadly because of many factors, including their spores being resilient.[15] Thermophilic bacteria thrive at higher temperatures, reaching 40–60 °C (104–140 °F) in typical mixes. Large-scale composting operations, such aswindrow composting, may exceed this temperature, potentially killing beneficial soil microorganisms but alsopasteurizing the waste.[13]
Actinomycetota are needed to break down paper products such as newspaper,bark, etc., and other large molecules such as lignin and cellulose that are more difficult to decompose.[3] The "pleasant, earthy smell of compost" is attributed to Actinomycetota.[3] They make carbon, ammonia, and nitrogen nutrients available to plants.[3]
Fungi such asmolds andyeasts help break down materials that bacteria cannot, especially cellulose andlignin in woody material.[3]
Protozoa contribute to biodegradation of organic matter and consume inactive bacteria, fungi, and micro-organic particulates.[16]
Earthworms ingest partly composted material and excrete worm castings,[3] making nitrogen, calcium, phosphorus, and magnesium available to plants.[3] The tunnels they create as they move through the compost also increase aeration and drainage.[3]
Flies feed on almost all organic material and put bacteria into the compost.[3] Their population is kept in check bymites and the thermophilic temperatures that are unsuitable for fly larvae.[3]
Under ideal conditions, composting proceeds through three major phases:[16][17]
Mesophilic phase: The initial, mesophilic phase is when the decomposition is carried out under moderate temperatures bymesophilic microorganisms. 2 to 8 days
Thermophilic phase: As the temperature rises, a second, thermophilic phase starts, in which variousthermophilic bacteria carry out the decomposition under higher temperatures (50 to 60 °C (122 to 140 °F).)
Cooling phase (also called Mesophilic II)
Maturation phase: As the supply of high-energy compounds dwindles, the temperature starts to decrease.
Semicomposting is the degradation process that handles volumes of organic waste lower than that recommended for composting and therefore does not present athermophilic stage, becausemesophilic microorganisms are the only responsible ones, for the degradation oforganic matter.[18][19]
The time required to compost material relates to the volume of material, the particle size of the inputs (e.g.wood chips break down faster than branches), and the amount of mixing and aeration.[3] Generally, larger piles reach higher temperatures and remain in a thermophilic stage for days or weeks. This is hot composting and is the usual method for large-scale municipal facilities and agricultural operations.
The Berkeley method produces finished compost in 18 days. It requires assembly of at least 1 cubic metre (35 cu ft) of material at the outset and needs turning every two days after an initial four-day phase.[20] Such short processes involve some changes to traditional methods, including smaller, more homogenized particle sizes in the input materials, controlling carbon-to-nitrogen ratio (C:N) at 30:1 or less, and careful monitoring of the moisture level.
Cold composting is a slower process that can take up to a year to complete.[21] It results from smaller piles, including many residential compost piles that receive small amounts of kitchen and garden waste over extended periods. Piles smaller than 1 cubic metre (35 cu ft) tend not to reach and maintain high temperatures.[22] Turning is not necessary with cold composting, although a risk exists that parts of the pile may go anaerobic as it becomes compacted or waterlogged.
Composting can destroy somepathogens andseeds, by reaching temperatures above 50 °C (122 °F).[23] Dealing with stabilized compost – i.e. composted material in which microorganisms have finished digesting the organic matter and the temperature has reached between 50 and 70 °C (122 and 158 °F) – poses very little risk, as these temperatures kill pathogens and even makeoocysts unviable.[24] The temperature at which a pathogen dies depends on the pathogen, how long the temperature is maintained (seconds to weeks), and pH.[25]
Compost products such as compost tea and compost extracts have been found to have an inhibitory effect onFusarium oxysporum,Rhizoctonia species, andPythium debaryanum, plant pathogens that can cause crop diseases.[26] Aerated compost teas are more effective than compost extracts.[26] Themicrobiota and enzymes present in compost extracts also have a suppressive effect on fungal plant pathogens.[27] Compost is a good source ofbiocontrol agents likeB. subtilis,B. licheniformis, and P.chrysogenum that fight plant pathogens.[26] Sterilizing the compost, compost tea, or compost extracts reduces the effect of pathogen suppression.[26]
Diseases that can be contracted from handling compost
When turning compost that has not gone through phases where temperatures above 50 °C (122 °F) are reached, a mouth mask and gloves must be worn to protect from diseases that can be contracted from handling compost, including:[28]
Compost adds organic matter to the soil and increases the nutrient content and biodiversity of microbes in soil.[29] Composting at home reduces the amount of green waste being hauled to dumps or composting facilities. The reduced volume of materials being picked up by trucks results in fewer trips, which in turn lowers the overall emissions from the waste-management fleet.
Potential sources of compostable materials, or feedstocks, include residential, agricultural, and commercial waste streams. Residential food or yard waste can be composted at home,[30] 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.[31][32]
A large compost pile is steaming with the heat generated bythermophilic microorganisms.
The two broad categories of organic solid waste are green and brown. Green waste is generally considered a source of nitrogen and includes pre- and post-consumerfood waste, grass clippings, garden trimmings, and fresh leaves.[1] Animal carcasses, roadkill, and butcher residue can also be composted, and these are considered nitrogen sources.[33]
Brown waste is a carbon source. Typical examples are dried vegetation and woody material such as fallen leaves, straw, woodchips, limbs, logs, pine needles, sawdust, and wood ash, but not charcoal ash.[1][34] Products derived from wood such as paper and plain cardboard are also considered carbon sources.[1]
On many farms, the basic composting ingredients are animalmanure generated on the farm as anitrogen source, and bedding as the carbon source. Straw and sawdust are common bedding materials. Nontraditional bedding materials are also used, including newspaper and chopped cardboard.[1] 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 must be blended with high-carbon, low-nitrogen materials.[35]
Human excreta, sometimes called "humanure" in the composting context,[36][37] can be added as an input to the composting process since it is a nutrient-rich organic material. Nitrogen, which serves as a building block for important plant amino acids, is found in solid human waste.[38][39] Phosphorus, which helps plants convert sunlight into energy in the form of ATP, can be found in liquid human waste.[40][41]
Solid human waste can be collected directly incomposting toilets, or indirectly in the form ofsewage sludge after it has undergone treatment in asewage treatment plant. Both processes require capable design, as potential health risks 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.[42] 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 asbiosolids, can be contaminated with a variety of metals and pharmaceutical compounds.[43][44] Insufficient processing of biosolids can also lead to problems when the material is applied to land.[45]
Urine can be put on compost piles or directly used as fertilizer.[46] Adding urine to compost can increase temperatures, so can increase its ability to destroy pathogens and unwanted seeds. Unlike feces, urine does not attract disease-spreading flies (such ashouseflies orblowflies), and it does not contain the most hardy of pathogens, such asparasitic worm eggs.[47]
Although the natural decomposition of human corpses into soil is a long-standing practice, a more rapid process that was developed in the early 21st century by Katrina Spade, entails encasing human corpses in wood chips, straw, and alfalfa untilthermophilemicrobes decompose the body.[51] In this manner, the transformation can be sped up to as little as 1–2 months.[51] The accelerated process is based in part on techniques developed for the composting of livestock.[51]
Though human composting was common before modern burial practices and in some religious traditions, contemporary society has tended to favor other disposition methods. However, cultural attention to concerns like sustainability and environmentally friendly burial has led to a resurgence in interest in direct composting of human bodies.[51] Some religious and cultural communities have been critical of this modern composting practice, even though it is in many ways a return to more traditional practices. Human composting is legal in multiple US states, andnatural burials without acasket or with a biodegradable container are common practice in Muslim and Jewish traditions and are allowed in the UK, the US, and many other locations throughout the world.[52][53]
In-vessel composting generally describes a group of methods that confine thecomposting materials within a building, container, or vessel.[54] In-vessel composting systems can consist of metal or plastic tanks or concrete bunkers in which air flow and temperature can be controlled, using the principles of a "bioreactor". Generally the air circulation is metered in via buried tubes that allow fresh air to be injected under pressure, with the exhaust being extracted through abiofilter, with temperature and moisture conditions monitored using probes in the mass to allow maintenance of optimumaerobic decomposition conditions.
This technique is generally used for municipal scaleorganic waste processing, including final treatment of sewagebiosolids, to a stable state with safe pathogen levels, for reclamation as a soil amendment. In-vessel composting can also refer toaerated static pile composting with the addition of removable covers that enclose the piles, as with the system in extensive use by farmer groups in Thailand, supported by the National Science and Technology Development Agency there.[55] In recent years, smaller scale in-vessel composting has been advanced. These can even use common roll-off waste dumpsters as the vessel. The advantage of using roll-off waste dumpsters is their relatively low cost, wide availability, they are highly mobile, often do not need building permits and can be obtained by renting or buying.
Aerated static pile (ASP) composting refers to any of a number of systems used to biodegrade organic material without physical manipulation during primarycomposting. The blended admixture is usually placed on perforated piping, providing air circulation for controlledaeration. It may be inwindrows, open or covered, or inclosed containers. With regard to complexity and cost, aerated systems are most commonly used by larger, professionally managed composting facilities, although the technique may range from very small, simple systems to very large, capital intensive, industrial installations.[56]
Aerated static piles offerprocess control for rapidbiodegradation, and work well for facilities processing wet materials and large volumes of feedstocks. ASP facilities can be under roof or outdoorwindrow composting operations, or totally enclosedin-vessel composting, sometimes referred to tunnel composting.
The practice of making raised garden beds or mounds filled with rotting wood is also calledHügelkultur in German.[58][59] It is in effect creating anurse log that is covered with soil.
Benefits ofHügelkultur garden beds include water retention and warming of soil.[58][60] Buried wood acts like asponge as it decomposes, able to capture water and store it for later use by crops planted on top of the bed.[58][61]
Composting toilet at Activism Festival 2010 in the mountains outside Jerusalem
Acomposting toilet is a type ofdry toilet that treatshuman waste by a biological process called composting. This process leads to thedecomposition oforganic matter and turns human waste into compost-like material. Composting is carried out by microorganisms (mainlybacteria andfungi) under controlledaerobic conditions.[62] Most composting toilets use no water for flushing and are therefore called "dry toilets".
In many composting toilet designs, a carbon additive such assawdust,coconut coir, orpeat 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 potentialodor. Most composting toilet systems rely onmesophilic composting. Longer retention time in the composting chamber also facilitatespathogen 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 ahumus-like end product that can be used to enrich soil if local regulations allow this. Some composting toilets haveurine diversion systems in the toilet bowl to collect the urine separately and control excess moisture. Avermifilter toilet is a composting toilet with flushing water whereearthworms are used to promote decomposition to compost.
Vermicompost (also calledworm castings, worm humus, worm manure, or worm faeces) is the end product of the breakdown oforganic matter by earthworms.[63] These castings have been shown to contain reduced levels of contaminants and a higher saturation of nutrients than the organic materials before vermicomposting.[64]
Black soldier fly (Hermetia illucens) larvae are able to rapidly consume large amounts of organic material and can be used to treat human waste. The resulting compost still contains nutrients and can be used forbiogas production, or further traditional composting or vermicomposting[65][66]
Bokashi is a fermentation process rather than a decomposition process, and so retains the feedstock's energy, nutrient and carbon contents. There must be sufficient carbohydrate for fermentation to complete and therefore the process is typically applied to food waste, including noncompostable items. Carbohydrate is transformed into lactic acid, which dissociates naturally to form lactate, a biological energy carrier. The preserved result is therefore readily consumed by soil microbes and from there by the entire soil food web, leading to a significant increase in soil organic carbon and turbation. The process completes in weeks and returns soil acidity to normal.
Co-composting is a technique that processes organic solid waste together with other input materials such as dewateredfecal sludge orsewage sludge.[10]
Anaerobic digestion combined with mechanical sorting of mixed waste streams is increasingly being used in developed countries due to regulations controlling the amount of organic matter allowed in landfills. Treatingbiodegradable waste before it enters a landfill reducesglobal warming from fugitivemethane; untreated waste breaks down anaerobically in a landfill, producinglandfill gas that contains methane, a potentgreenhouse gas. The methane produced in an anaerobic digester can be used asbiogas.[67]
On open ground for growingwheat,corn,soybeans, and similar crops, compost can be broadcast across the top of the soil using spreader trucks or spreaders pulled behind a tractor. It is expected that the spread layer is very thin (approximately 6 mm (0.24 in)) and worked into the soil prior to planting. Application rates of 25 mm (0.98 in) or more are not unusual when trying to rebuild poor soils or control erosion. Due to the extremely high cost of compost per unit of nutrients in the United States, on-farm use is relatively rare since rates over 4 tons/acre may not be affordable. This results from an over-emphasis on "recycling organic matter" than on "sustainable nutrients." In countries such as Germany, where compost distribution and spreading are partially subsidized in the original waste fees, compost is used more frequently on open ground on the premise of nutrient "sustainability".[68]
Inplasticulture,strawberries,tomatoes,peppers,melons, and other fruits and vegetables are grown under plastic to control temperature, retain moisture and control weeds. Compost may be banded (applied in strips along rows) and worked into the soil prior to bedding and planting, be applied at the same time the beds are constructed and plastic laid down, or used as a top dressing.
Many crops are not seeded directly in the field but are started in seed trays in a greenhouse. When the seedlings reach a certain stage of growth, they aretransplanted in the field. Compost may be part of the mix used to grow the seedlings, but is not normally used as the only planting substrate. The particular crop and the seeds' sensitivity to nutrients, salts, etc. dictates the ratio of the blend, and maturity is important to insure that oxygen deprivation will not occur or that no lingering phyto-toxins remain.[69]
Compost can be added to soil,coir, orpeat, as atilth improver, supplying humus and nutrients.[70] It provides a rich growing medium as absorbent material. This material contains moisture and soluble minerals, which provide support andnutrients. Although it is rarely used alone, plants can flourish from mixedsoil that includes a mix of compost with other additives such assand, grit, bark chips,vermiculite,perlite, orclay granules to produceloam. 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.[1][70]
Generally, direct seeding into a compost is not recommended due to the speed with which it may dry, the possible presence ofphytotoxins in immature compost that may inhibit germination,[71][72][73] and the possible tie up of nitrogen by incompletely decomposed lignin.[74] It is very common to see blends of 20–30% compost used for transplantingseedlings.
Compost can be used to increase plant immunity to diseases and pests.[75]
Compost tea is made up of extracts of fermented water leached from composted materials.[70][76] Composts can be either aerated or non-aerated depending on itsfermentation process.[77] Compost teas are generally produced from adding compost to water in a ratio of 1:4–1:10, occasionally stirring to releasemicrobes.[77]
There is debate about the benefits of aerating the mixture.[76] Non-aerated compost tea is cheaper and less labor-intensive, but there are conflicting studies regarding the risks ofphytotoxicity and human pathogen regrowth.[77] Aerated compost tea brews faster and generates more microbes, but has potential for human pathogen regrowth, particularly when one adds additional nutrients to the mixture.[77]
Field studies have shown the benefits of adding compost teas to crops due to organic matter input, increased nutrient availability, and increased microbial activity.[70][76] They have also been shown to have a suppressive effect on plant pathogens[78] and soil-borne diseases.[77] The efficacy is influenced by a number of factors, such as the preparation process, the type of source the conditions of the brewing process, and the environment of the crops.[77] Adding nutrients to compost tea can be beneficial for disease suppression, although it can trigger the regrowth of human pathogens likeE. coli andSalmonella.[77]
Compost is sold as bagged potting mixes in garden centers and other outlets.[79][70] 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,[79] grow bags, 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.[80][81]
A kitchen compost bin is used to transport compostable items to an outdoor compost bin.
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.[84] Compost is regulated in Canada[85] and Australia[86] as well.
EPA Class A and B guidelines in the United States[87] were developed solely to manage the processing andbeneficial reuse ofsludge, also now calledbiosolids, following the US EPA ban of ocean dumping. About 26 American states now require composts to be processed according to these federal protocols forpathogen andvector control, even though the application to non-sludge materials has not been scientifically tested. An example is that green waste composts are used at much higher rates than sludge composts were ever anticipated to be applied at.[88] U.K guidelines also exist regarding compost quality,[89] as well as Canadian,[90] Australian,[91] and the various European states.[92]
In the United States, some compost manufacturers participate in a testing program offered by a private lobbying organization called the U.S. Composting Council. The USCC was originally established in 1991 by Procter & Gamble to promote composting of disposable diapers, following state mandates to ban diapers in landfills, which caused a national uproar. Ultimately the idea of composting diapers was abandoned, partly since it was not proven scientifically to be possible, and mostly because the concept was a marketing stunt in the first place. After this, composting emphasis shifted back to recycling organic wastes previously destined for landfills. There are no bonafide quality standards in America, but the USCC sells a seal called "Seal of Testing Assurance"[93] (also called "STA"). For a considerable fee, the applicant may display the USCC logo on products, agreeing to volunteer to customers a current laboratory analysis that includes parameters such as nutrients, respiration rate, salt content, pH, and limited other indicators.[94]
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.[99]
There are health risk concerns aboutPFASs ("forever chemicals") levels in compost derived from sewage sledge sourced biosolids, andEPA has not set health risk standards for this. TheSierra Club recommends that home gardeners avoid the use of sewage sludge-base fertilizer and compost, in part due to potentially high levels of PFASs.[100] The EPAPFAS Strategic Roadmap initiative, running from 2021 to 2024, will consider the full lifecycle of PFAS including health risks of PFAS in wastewater sludge.[101]
Composting dates back to at least the early Roman Empire and was mentioned as early asCato the Elder's 160 BCE pieceDe Agri Cultura.[102] 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. Methodologies for organic composting were part oftraditional agricultural systems around the world.
Composting began to modernize somewhat in the 1920s in Europe as a tool fororganic farming.[103] The first industrial station for the transformation of urban organic materials into compost was set up inWels, Austria, in the year 1921.[104] Early proponents of composting in farming includeRudolf Steiner, founder of a farming method calledbiodynamics, andAnnie Francé-Harrar, who was appointed on behalf of the government inMexico and supported the country in 1950–1958 to set up a large humus organization in the fight against erosion andsoil degradation.[105]Sir Albert Howard, who worked extensively inIndia on sustainable practices,[103] andLady Eve Balfour were also major proponents of composting. Modern scientific composting was imported to America by the likes ofJ. I. Rodale – founder ofRodale, Inc. Organic Gardening, and others involved in the organic farming movement.[103]
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