Compost
Encyclopedia
Compost is organic matter
Organic matter
Organic matter is matter that has come from a once-living organism; is capable of decay, or the product of decay; or is composed of organic compounds...

 that has been decomposed
Biodegradation
Biodegradation or biotic degradation or biotic decomposition is the chemical dissolution of materials by bacteria or other biological means...

 and recycled as a fertilizer and soil amendment. Compost is a key ingredient in organic farming
Organic farming
Organic farming is the form of agriculture that relies on techniques such as crop rotation, green manure, compost and biological pest control to maintain soil productivity and control pests on a farm...

. At its most essential, the process of composting requires simply piling up waste outdoors and waiting for the materials to break down from anywhere between 5-6 weeks or even more. Modern, methodical composting is 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. Worms and fungi further break up the material. Aerobic bacteria manage the chemical process by converting the inputs into heat, carbon dioxide and ammonium. The ammonium is further converted by bacteria into plant-nourishing nitrite
Nitrite
The nitrite ion has the chemical formula NO2−. The anion is symmetric with equal N-O bond lengths and a O-N-O bond angle of ca. 120°. On protonation the unstable weak acid nitrous acid is produced. Nitrite can be oxidised or reduced, with product somewhat dependent on the oxidizing/reducing agent...

s and nitrate
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...

s through the process of nitrification
Nitrification
Nitrification is the biological oxidation of ammonia with oxygen into nitrite followed by the oxidation of these nitrites into nitrates. Degradation of ammonia to nitrite is usually the rate limiting step of nitrification. Nitrification is an important step in the nitrogen cycle in soil...

.

Compost can be rich in nutrients. It is used in gardens, landscaping
Landscaping
Landscaping refers to any activity that modifies the visible features of an area of land, including:# living elements, such as flora or fauna; or what is commonly referred to as gardening, the art and craft of growing plants with a goal of creating a beautiful environment within the landscape.#...

, horticulture
Horticulture
Horticulture is the industry and science of plant cultivation including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding and genetic...

, and agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

. The compost itself is beneficial for the land in many ways, including as a soil conditioner
Soil conditioner
A soil conditioner, also called a soil amendment, is a material added to soil to improve plant growth and health. A conditioner or a combination of conditioners corrects the soil's deficiencies in structure and-or nutrients.-Purpose:...

, a fertilizer
Fertilizer
Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...

, addition of vital humus or humic acids, and as a natural pesticide
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...

 for soil. In ecosystems, compost is useful for erosion control, land and stream reclamation, wetland construction, and as landfill cover (see compost uses
Compost uses
Compost is a versatile product resulting from composting - the biodegradation of organic waste, industrially, commercially or domestically produced. The basic use is conditioning and fertilizing soil by the addition of humus, nutrients and beneficial soil bacteria, with a wide range of specific...

). Organic ingredients intended for composting can alternatively be used to generate biogas
Biogas
Biogas typically refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal dung, and kitchen waste can be converted into a gaseous fuel called biogas...

 through anaerobic digestion
Anaerobic digestion
Anaerobic digestion is a series of processes in which microorganisms break down biodegradable material in the absence of oxygen. It is used for industrial or domestic purposes to manage waste and/or to release energy....

. Anaerobic digestion is fast overtaking composting in some parts of the world including central Europe as a primary means of downcycling waste organic matter.

History

Composting as a recognized practice dates to at least the early Roman Empire since Pliny the Elder
Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

 (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. The first industrial station for the transformation of urban organic materials into compost was set up in Wels/Austria in the year 1921. The early personages most cited for propounding composting within farming are for the German-speaking world Rudolf Steiner
Rudolf Steiner
Rudolf Joseph Lorenz Steiner was an Austrian philosopher, social reformer, architect, and esotericist. He gained initial recognition as a literary critic and cultural philosopher...

, founder of a farming method called biodynamics, and Annie Francé-Harrar
Annie Francé-Harrar
Annie Francé-Harrar was an Austrian writer and scientist.Francé-Harrar created the scientific basis for the humus-compost-economy together with her second husband Raoul Heinrich Francé...

, who was appointed on behalf of the government in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 and supported the country 1950–1958 to set up a large humus organization in the fight against erosion and soil degradation. In the English-speaking world it was Sir Albert Howard who worked extensively in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 on sustainable practices and Lady Eve Balfour
Lady Eve Balfour
Lady Evelyn Barbara "Eve" Balfour was an English farmer, educator, organic farming pioneer, and a founding figure in the organic movement. She was one of the first women to study agriculture at an English university, graduating from the University of Reading.The daughter of the second Earl of...

 who was a huge proponent of composting. Composting was imported to America by various followers of these early European movements in the form of persons such as J.I. Rodale
Jerome Irving Rodale
Jerome Irving Rodale , was a playwright, editor, author, and founder of Rodale, Inc....

 (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. Many such short processes involve a few changes to traditional methods, including smaller, more homogenized pieces in the compost, controlling carbon to nitrogen (CN) ratio
Carbon to nitrogen ratio
The C/N ratio or carbon-to-nitrogen ratio is a ratio of the mass of carbon to the mass of nitrogen in a substance. It can, amongst other things, be used in analysing sediments and compost...

 at 30 to 1 or less, and monitoring the moisture level more carefully. However, none of these parameters differ significantly from early writings of Howard and Balfour, suggesting that in fact modern composting has not made significant advances over the traditional methods that take a few months to work. For this reason and others, many modern scientists who deal with carbon transformations are sceptical that there is a "super-charged" way to get nature to make compost rapidly. They also point to the fact that it is the structure of the natural molecules - such as carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...

s, protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s, and cellulose
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....

 - that really dictate the rate at which microbial-mediated transformations are possible.

Some cities such as Seattle and San Francisco
San Francisco Mandatory Recycling and Composting Ordinance
The San Francisco Mandatory Recycling and Composting Ordinance is a local municipal ordinance requiring all persons located in San Francisco to separate their recyclables, compostables and landfilled trash and to participate in recycling and composting programs...

 require food and yard waste to be sorted for composting.

Ingredients

Composting organisms require four equally important things to work effectively:
  • Carbon — for energy; the microbial oxidation of carbon produces the heat, if included at suggested levels http://web.extension.illinois.edu/homecompost/science.html.
    • 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.


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
Evaporation
Evaporation is a type of vaporization of a liquid that occurs only on the surface of a liquid. The other type of vaporization is boiling, which, instead, occurs on the entire mass of the liquid....

 ("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) 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). Fresh grass clippings have an average ratio of about 15 to 1 and dry autumn leaves about 50 to 1 depending on 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 in time. Observation of amounts, and consideration of different materials as a pile is built over time, can quickly achieve a workable technique for the individual situation.

Urine

People excrete far more of certain water-soluble plant nutrients (nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

, phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...

, potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...

) in urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...

 than in feces
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...

. Human urine can be used directly as fertilizer or it can be put onto compost. Adding a healthy person's urine to compost usually will increase temperatures and therefore increase its ability to destroy pathogens and unwanted seeds. Urine from a person with no obvious symptoms of infection is generally much more sanitary than fresh feces. Unlike feces, urine doesn't attract disease-spreading flies
Fließ
Fließ is a municipality in the Landeck district and is located5 km south of Landeck on the upper course of the Inn River. It has 9 hamlets and was already populated at the roman age; the village itself was founded around the 6th century. After a conflagration in 1933 Fließ was restored more...

 (such as house flies or blow flies), and it doesn't contain the most hardy of pathogens, such as parasitic worm
Parasitic worm
Parasitic worms or helminths are a division of eukaryoticparasites that, unlike external parasites such as lice and fleas, live inside their host. They are worm-like organisms that live and feed off living hosts, receiving nourishment and protection while disrupting their hosts' nutrient...

 eggs. Urine usually does not stink
Odor
An odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors...

 for long, particularly when it is fresh, diluted, or put on sorbent
Sorbent
A sorbent is a material used to absorb liquids or gases. Examples include:*A material similar to molecular sieve material. It has a large internal surface area and good thermal conductivity. It is typically supplied in pellets of 1 mm to 2 mm diameter and roughly 5 mm length or as...

s.

Urine is primarily composed of water and urea
Urea
Urea or carbamide is an organic compound with the chemical formula CO2. The molecule has two —NH2 groups joined by a carbonyl functional group....

. 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
Phytotoxicity
Phytotoxicity is a term used to describe the degree of toxic effect by a compound on plant growth. Such damage may be caused by a wide variety of compounds, including trace metals, pesticides, salinity, phytotoxins or allelopathy.-Urea and urine:...

.

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.

Micro-organisms

With the proper mixture of water, oxygen, carbon, and nitrogen, micro-organisms are allowed to break down organic matter to produce compost. The composting process is dependant on micro-organisms to break down organic matter into compost. There are many types of microorganisms found in active compost of which the most common are:
  • Bacteria
    Bacteria
    Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

    - The most numerous of all the micro organisms found in compost.
  • Actinomycetes- Necessary for breaking down paper products such as newspaper, bark
    Bark
    Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...

    , etc.
  • Fungi- Molds and yeast
    Yeast
    Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...

     help break down materials that bacteria cannot, especially lignin
    Lignin
    Lignin or lignen is a complex chemical compound most commonly derived from wood, and an integral part of the secondary cell walls of plants and some algae. The term was introduced in 1819 by de Candolle and is derived from the Latin word lignum, meaning wood...

     in woody material.
  • Protozoa
    Protozoa
    Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...

    - Help consume bacteria, fungi and micro organic particulates.
  • Rotifers- Rotifers help control populations of bacteria and small protozoans.


In addition, earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...

s 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.

Common items suitable for composting

These common items can likely be added to compost with no negative effect.
  • Paperboard
    Paperboard
    Paperboard is a thick paper based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker than paper. According to ISO standards, paperboard is a paper with a basis weight above 224 g/m2, but there are exceptions. Paperboard can be single...

     or clean paper
    Paper
    Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....

  • Dried-out egg shells
  • Leaves, garden trimmings
  • Fruits and vegetables
  • Coffee and tea

Uses

Compost is generally recommended as an additive to soil, or other matrices such as coir
Coir
Coir is a natural fibre extracted from the husk of coconut and used in products such as floor mats, doormats, brushes, mattresses etc. Technically coir is the fibrous material found between the hard, internal shell and the outer coat of a coconut. Other uses of brown coir are in upholstery...

 and peat
Peat
Peat is an accumulation of partially decayed vegetation matter or histosol. Peat forms in wetland bogs, moors, muskegs, pocosins, mires, and peat swamp forests. Peat is harvested as an important source of fuel in certain parts of the world...

, as a tilth
Tilth
Tilth can refer to two things:Tillage and a measure of the health of soil.Good tilth is a term referring to soil that has the proper structure and nutrients to grow healthy crops. Soil in good tilth is loamy, nutrient-rich soil that can also be said to be friable because optimal soil has a mixture...

 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
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

, sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

, grit, bark chips, vermiculite
Vermiculite
Vermiculite is a natural mineral that expands with the application of heat. The expansion process is called exfoliation and it is routinely accomplished in purpose-designed commercial furnaces. Vermiculite is formed by weathering or hydrothermal alteration of biotite or phlogopite...

, perlite
Perlite
Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently...

, or clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

 granules to produce loam
Loam
Loam is soil composed of sand, silt, and clay in relatively even concentration . Loam soils generally contain more nutrients and humus than sandy soils, have better infiltration and drainage than silty soils, and are easier to till than clay soils...

. 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.

Generally, direct seeding into a compost is not recommended due to the speed with which it may dry and the possible presence of phytotoxin
Phytotoxin
Phytotoxin refers to a substance produced by a plant that is toxic or a substance that is toxic to the plant Many substances produced by plants are secondary metabolites and are the by-products of primary physiological processes...

s that may inhibit germination, and the possible tie up of nitrogen by incompletely decomposed lignin. It is very common to see blends of 20–30% compost used for transplanting seedlings at cotyledon
Cotyledon
A cotyledon , is a significant part of the embryo within the seed of a plant. Upon germination, the cotyledon may become the embryonic first leaves of a seedling. The number of cotyledons present is one characteristic used by botanists to classify the flowering plants...

 stage or later.

Destroying pathogens, seeds, or unwanted plants

Composting can destroy pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...

s or unwanted seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s. Unwanted living plants (or weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...

s) can be discouraged by covering with mulch/compost.

The "microbial pesticides
Biopesticide
Biopesticides include "naturally occurring substances that control pests , microorganisms that control pests , and pesticidal substances produced by plants containing added genetic material or PIPs."Biopesticides are biochemical pesticides that are naturally occurring substances that control pests...

" in compost may include thermophile
Thermophile
A thermophile is an organism — a type of extremophile — that thrives at relatively high temperatures, between 45 and 122  °C . Many thermophiles are archaea...

s and mesophile
Mesophile
A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold, typically between 25 and 40 °C...

s, 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 prion
Prion
A prion is an infectious agent composed of protein in a misfolded form. This is in contrast to all other known infectious agents which must contain nucleic acids . The word prion, coined in 1982 by Stanley B. Prusiner, is a portmanteau derived from the words protein and infection...

s).

The sanitizing
Disinfection
Disinfectants are substances that are applied to non-living objects to destroy microorganisms that are living on the objects. Disinfection does not necessarily kill all microorganisms, especially nonresistant bacterial spores; it is less effective than sterilisation, which is an extreme physical...

 qualities of (thermophilic) composting are desirable where there is a high likelihood of pathogens, such as with manure
Manure
Manure is organic matter used as organic fertilizer in agriculture. Manures contribute to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that are trapped by bacteria in the soil...

. Applications include humanure composting or the deep litter
Deep litter
Deep litter is an animal housing system, based on the repeated spreading of straw or sawdust material in indoor booths. An initial layer of litter is spread for the animals to use for bedding material and to defecate in, and as the litter is soiled, new layers of litter are continuously added by...

 technique.

Types

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.

Bokashi composting

Bokashi composting uses an aerobic
Aerobic organism
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...

 or anaerobic
Anaerobic organism
An anaerobic organism or anaerobe is any organism that does not require oxygen for growth. It could possibly react negatively and may even die if oxygen is present...

 inoculation to produce the compost. Once a starter culture is made, it can be used to extend the culture indefinitely, like yogurt culture. Since the popular introduction of effective microorganism
Effective microorganism
An effective microorganism refers to any of the predominantly anaerobic organisms blended in commercial agricultural amendments, medicines, and nutritional supplements based on the trademarked product originally marketed as EM-1 Microbial Inoculant, aka Effective Microorganisms and EM Technology...

s (EM), bokashi is commonly made with only molasses
Molasses
Molasses is a viscous by-product of the processing of sugar cane, grapes or sugar beets into sugar. The word molasses comes from the Portuguese word melaço, which ultimately comes from mel, the Latin word for "honey". The quality of molasses depends on the maturity of the sugar cane or sugar beet,...

, water, EM, and wheat bran.

In home composting applications, kitchen waste is placed into a container (often known as a bokashi bin or bokashi bucket) that can be sealed with an air-tight lid. These scraps are then inoculated
Inoculation
Inoculation is the placement of something that will grow or reproduce, and is most commonly used in respect of the introduction of a serum, vaccine, or antigenic substance into the body of a human or animal, especially to produce or boost immunity to a specific disease...

 with a bokashi EM mix. This usually takes the form of a carrier, such as rice hulls
Rice hulls
Rice hulls are the hard protecting coverings of grains of rice. In addition to protecting rice during the growing season, rice hulls can be put to use as building material, fertilizer, insulation material, or fuel.-Production:...

, wheat bran, or sawdust, that has been inoculated with composting micro-organisms. The EM are natural lactic acid
Lactic acid
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...

 bacteria, yeast, and phototroph
Phototroph
Phototrophs are the organisms that carry out photosynthesis to acquire energy. They use the energy from sunlight to convert carbon dioxide and water into organic material to be utilized in cellular functions such as biosynthesis and respiration.Most phototrophs are autotrophs, also known as...

ic bacteria that act as a microbe community within the kitchen scraps, fermenting and accelerating breakdown of the organic matter. The user would place alternating layers of food scraps and Bokashi mix until the container is full. Liquid "compost tea" is drained once or twice a week and can be diluted 1:100 and added to plants as fertilizer, or poured directly down drains to help clean them. Once the container is full, it is left to ferment for one to two weeks in the container, and then buried under 6-8 inches of soil, in ground or in a non-reactive container. After another two weeks buried under soil, the food scraps should be broken down into rich humus.

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. The extract is applied as a spray to non-edible plant parts such as seedlings, or as a soil-drench (root dip), or as a surface spray to reduce incidence of harmful phytopathogenic fungi in the phyllosphere
Phyllosphere
The phyllosphere is a term used in microbiology to refer to leaf surfaces or total above-ground surfaces of a plant as a habitat for microorganisms. The below-ground microbial habitats The phyllosphere is a term used in microbiology to refer to leaf surfaces or total above-ground surfaces of a...

.

Hügelkultur

The practice of making raised beds filled with rotting wood. It is in effect creating a Nurse log
Nurse log
A nurse log is a fallen tree which, as it decays, provides ecological facilitation to seedlings. Broader definitions include providing shade or support to other plants. Some of the advantages a nurse log offers to a seedling are: water, moss thickness, leaf litter, mycorrhizae, disease protection,...

, however, covered with dirt. The buried decomposing wood will give off heat, as all compost does, for several years. This effect has been used by Sepp Holzer
Sepp Holzer
Josef "Sepp" Holzer is a farmer, author, and an international consultant for natural agriculture...

 for one to allow fruit trees to survive at otherwise inhospitable temperatures and altitudes.

"Humanure"

"Humanure" is a portmanteau neologism designating human excrement (feces and urine) that is recycled
Recycling
Recycling is processing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution and water pollution by reducing the need for "conventional" waste disposal, and lower greenhouse...

 via composting for agricultural or other purposes. The term was popularized in a 1994 book by Joseph Jenkins that advocates the use of this organic soil amendment.

Humanure is not traditional sewage
Sewage
Sewage is water-carried waste, in solution or suspension, that is intended to be removed from a community. Also known as wastewater, it is more than 99% water and is characterized by volume or rate of flow, physical condition, chemical constituents and the bacteriological organisms that it contains...

 that has been processed by waste-treatment
Sewage treatment
Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater and household sewage, both runoff and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants...

 facilities, which may include waste from industrial
Industry
Industry refers to the production of an economic good or service within an economy.-Industrial sectors:There are four key industrial economic sectors: the primary sector, largely raw material extraction industries such as mining and farming; the secondary sector, involving refining, construction,...

 and other sources; rather, it is the combination of feces and urine with paper and additional carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

 material (such as sawdust
Sawdust
Sawdust is a by-product of cutting lumber with a saw, composed of fine particles of wood. It can present a hazard in manufacturing industries, especially in terms of its flammability....

). A humanure system, such as a composting toilet
Composting toilet
A composting toilet is a dry toilet that using a predominantly aerobic processing system that treats excreta, typically with no water or small volumes of flush water, via composting or managed aerobic decomposition...

, does not require water or electricity, and when properly managed does not smell. 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".

By disposing of feces and urine through composting, the nutrients contained in them are returned to the soil. This aids in preventing soil degradation. Human fecal matter and urine have high percentages of nitrogen, phosphorus, potassium, carbon, and calcium. It is equal to many fertilizers and manures purchased in garden stores. Humanure aids in the conservation of fresh water
Fresh Water
Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...

 by avoiding the usage of potable water required by the typical flush toilet
Toilet
A toilet is a sanitation fixture used primarily for the disposal of human excrement, often found in a small room referred to as a toilet/bathroom/lavatory...

. It further prevents the pollution of ground water by controlling the fecal matter decomposition before entering the system. When properly managed, there should be no ground contamination from leachate
Leachate
Leachate is any liquid that, in passing through matter, extracts solutes, suspended solids or any other component of the material through which it has passed....

.

As a substitute for a flush water process, it reduces the energy consumption and, hence, greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...

 emissions associated with the transportation and processing of water
Water purification
Water purification is the process of removing undesirable chemicals, materials, and biological contaminants from contaminated water. The goal is to produce water fit for a specific purpose...

 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
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

 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
Night soil
Night soil is a euphemism for human excrement collected at night from cesspools, privies, etc. and sometimes used as a fertilizer. Night soil is produced as a result of a waste management system in areas without community infrastructure such as a sewage treatment facility, or individual septic...

, 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 vast 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.

Vermicompost

Vermicompost
Vermicompost
Vermicompost is the product or process of composting utilizing various species of worms, usually red wigglers, white worms, and earthworms to create a heterogeneous mixture of decomposing vegetable or food waste, bedding materials, and vermicast...

 is the product of composting utilizing various species of worms, usually red wigglers, white worms
Enchytraeus buchholzi
Enchytraeus buchholzi are cultured by aquarists as a fish food.Whiteworms ~ Enchytraeus albidus are probably one of the most popular forms of live food cultured by aquarists...

, and earthworms to create a heterogeneous mixture of decomposing vegetable or food waste (not to include meat, dairy, fats, or oils), bedding materials, and vermicast. Vermicast, also known as worm castings, worm humus or worm manure, is the end-product of the breakdown of organic matter by species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of earthworm. This type of composting is sometimes suggested as a feasible indoor composting method

The earthworm species (or composting worms) most often used are red wigglers (Eisenia foetida or Eisenia andrei
Eisenia andrei
Eisenia andrei is a close relative of the 'brandling' or 'tiger' worm, Eisenia fetida. Like its sibling species, it is epigeic, i.e. it prefers to live in compost or leaf litter rather than mineral soils....

), though European nightcrawlers (Eisenia hortensis) 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, and Belgian nightcrawlers.

Containing water-soluble nutrients, vermicompost is a nutrient-rich organic fertilizer
Organic fertilizer
Organic fertilizers are naturally occurring fertilizers .Naturally occurring organic fertilizers include manure, slurry, worm castings, peat, seaweed, humic acid, and guano. Sewage sludge use in organic agricultural operations in the U.S...

 and soil conditioner in a form that is relatively easy for plants to absorb. Worm castings are sometimes used as an organic fertilizer
Organic fertilizer
Organic fertilizers are naturally occurring fertilizers .Naturally occurring organic fertilizers include manure, slurry, worm castings, peat, seaweed, humic acid, and guano. Sewage sludge use in organic agricultural operations in the U.S...

. Because the earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...

s 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.

Vermicompost tea has been shown to cause a 173.5% increase in plant growth by mass over plants grown without castings. These results were seen with only 10% addition of castings to produce these results.

Alternative to land-filling

As concern about landfill
Landfill
A landfill site , is a site for the disposal of waste materials by burial and is the oldest form of waste treatment...

 space increases, worldwide interest in recycling by means of composting is growing, since composting is a process for converting decomposable organic materials into useful stable products. Industrial scale composting in the form of in-vessel composting
In-vessel composting
In-vessel composting is an industrial form of composting biodegradable waste that occurs in enclosed reactors. These generally consist of metal tanks or concrete bunkers in which air flow and temperature can be controlled, using the principles of a "bioreactor"...

, aerated static pile composting
Aerated static pile composting
Aerated Static Pile composting, refers to any of a number of systems used to biodegrade organic material without physical manipulation during primary composting. The blended admixture is usually placed on perforated piping, providing air circulation for controlled aeration .It may be in windrows,...

, and anaerobic digestion takes place in most Western countries now, and in many areas is mandated by law. 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. The USA is the only Western country that does not distinguish sludge-source compost from green-composts, and by default in the USA 50% of states expect composts to comply in some manner with the federal EPA 503 rule promulgated in 1984 for sludge products. Compost is regulated in Canada and Australia as well.

Industrial systems

Industrial composting systems are increasingly being installed as a waste management alternative to landfills, along with other advanced waste processing systems. Mechanical sorting of mixed waste streams combined with anaerobic digestion or in-vessel composting is called mechanical biological treatment
Mechanical biological treatment
A mechanical biological treatment system is a type of waste processing facility that combines a sorting facility with a form of biological treatment such as composting or anaerobic digestion...

, and are increasingly being used in developed countries due to regulations controlling the amount of organic matter allowed in landfills. Treating biodegradable waste
Biodegradable waste
Biodegradable waste is a type of waste, typically originating from plant or animal sources, which may be degraded by other living organisms. Waste that cannot be broken down by other living organisms are called non-biodegradable....

 before it enters a landfill reduces global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

 from fugitive methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...

; untreated waste breaks down anaerobically
Anaerobic respiration
Anaerobic respiration is a form of respiration using electron acceptors other than oxygen. Although oxygen is not used as the final electron acceptor, the process still uses a respiratory electron transport chain; it is respiration without oxygen...

 in a landfill, producing landfill gas
Landfill gas
Landfill gas is a complex mix of different gases created by the action of microorganisms within a landfill.-Production:Landfill gas production results from chemical reactions and microbes acting upon the waste as the putrescible materials begins to break down in the landfill...

 that contains methane
Atmospheric methane
Atmospheric methane levels are of interest due to its impact on climate change. Atmospheric methane is one of the most potent and influential greenhouse gases on Earth. The 100-year global warming potential of methane is 25, i.e...

, a potent greenhouse gas.

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 municipal solid waste
Municipal solid waste
Municipal solid waste , commonly known as trash or garbage , refuse or rubbish is a waste type consisting of everyday items we consume and discard. It predominantly includes food wastes, yard wastes, containers and product packaging, and other miscellaneous inorganic wastes from residential,...

 makes this approach less attractive. The world's largest MSW co-composter is the Edmonton Composting Facility
Edmonton Composting Facility
The Edmonton Composting Facility is the site of the City of Edmonton's advanced co-composting system for processing organic waste. Co-composting involves mixing household wastes with biosolids , to create compost. Together with the City's three recycling programs, Edmonton is able to divert 60% of...

 in Edmonton
Edmonton
Edmonton is the capital of the Canadian province of Alberta and is the province's second-largest city. Edmonton is located on the North Saskatchewan River and is the centre of the Edmonton Capital Region, which is surrounded by the central region of the province.The city and its census...

, Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...

, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, which turns 220,000 tonnes of residential solid waste and 22,500 dry tonnes of biosolids per year into 80,000 tonnes of compost. The facility is 38,690 meters2 (416,500 ft2), equivalent to 4½ Canadian football
Canadian football
Canadian football is a form of gridiron football played exclusively in Canada in which two teams of 12 players each compete for territorial control of a field of play long and wide attempting to advance a pointed prolate spheroid ball into the opposing team's scoring area...

 fields, and the operating structure is the largest stainless steel building in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, the size of 14 NHL rinks. In 2006, the State of Qatar awarded Keppel Seghers Singapore, a subsidiary of Keppel Corporation
Keppel Corporation
The Keppel Group of Companies includes Keppel Offshore & Marine, Keppel Integrated Engineering, Keppel Energy, Keppel Telecommunications & Transportation and Keppel Land, among others....

 to begin construction on a 275,000 tonne/year Anaerobic Digestion and Composting Plant licensed by Kompogas Switzerland. This plant, with 15 independent anaerobic digestors will be the world's largest composting facility once fully operational in early 2011 and forms part of the Qatar Domestic Solid Waste Management Center, the largest integrated waste management
Waste management
Waste management is the collection, transport, processing or disposal,managing and monitoring of waste materials. The term usually relates to materials produced by human activity, and the process is generally undertaken to reduce their effect on health, the environment or aesthetics...

 complex in the Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...

.

See also

  • Ecological sanitation
    Ecological sanitation
    Ecological sanitation, also known as ecosan or eco-san, are terms coined to describe a form of sanitation that usually involves urine diversion and the recycling of water and nutrients contained within human wastes back into the local environment....

  • List of composting systems
  • Municipal composting
  • San Francisco Mandatory Recycling and Composting Ordinance
    San Francisco Mandatory Recycling and Composting Ordinance
    The San Francisco Mandatory Recycling and Composting Ordinance is a local municipal ordinance requiring all persons located in San Francisco to separate their recyclables, compostables and landfilled trash and to participate in recycling and composting programs...


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)

External links



Organisations
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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