Did you ever wonder whether a hand-held windmill could be used for powering pocket-sized electronics, like cell phones? Well, a graduate student in India has done just that. Click on the link below the picture to read about how this little generator works.
Thursday, May 29, 2008
Saturday, May 17, 2008
Composting Meat???--A Discussion of Composting
For fairly obvious reasons, composting in an urban setting is a challenge, primarily because of odors. If you are fortunate enough to have a back yard, it is not as difficult, especially if you use worms or one of those specialized rapid-composting bins. However, for the apartment dweller, it is hard to move the compost pile far enough away from sensitive noses to be acceptable. So.... I started doing a little research on various options for urban composting.
COMPOSTING BASICS:
Composting itself is a process whereby microorganisms break down organic materials such as kitchen waste and grass clippings into a rich, earth-like substance called compost or humus. Essentially, any type of plant-material can be composted. There are very few types of non-plant material that are appropriate for composting, and we will discuss these a little later.
The following is information from the Cooperative Extension of the University of California:
A compost is made up of one or more organic materials that have been piled, with or without added soil, and allowed to decompose until the product breaks up readily, can be easily worked into the soil, or can be used as a potting mixture. Organic residues most utilized include leaves, lawn clippings, garden wastes, and animal manures. Because tree trimmings and woody plant stems decay slowly, they should first be chopped or chipped and then composted separately or mixed with other residues. Corn stalks and similar residues should also be chopped before piling. Some detrimental microbes and weed seeds may survive the composting process, so discard diseased plant materials and weeds that have gone to seed....
The process of decay The piled organic materials decompose primarily through the action of bacteria, fungi, and other soil organisms. Crop waste, soil, and dust contain the needed forms which establish themselves quickly under proper conditions for composting. These organisms function more effectively at favorable temperatures, with proper air and moisture, and in the presence of adequate supplies of nutrient elements, especially nitrogen. During decay, excess carbon evolves as carbon dioxide, and nitrogen and other plant nutrient elements become concentrated. The plant materials graduallyturn dark brown to almost black and lose their original structure. Microbial inoculations and other "special preparations" are not necessary for a good product....
Here are three other sites that have good, simple information on composting basics:
1) http://www.dep.state.pa.us/dep/deputate/airwaste/wm/recycle/compost/Home3.htm
2) http://www.montgomerycountymd.gov/deptmpl.asp?url=/content/dep/composting/basics.asp
3) http://www.compostinfo.com/tutorial/GreensAndBrowns.htm
Backyard Composting is primarily a biological process so you must feed your microorganisms to keep them happy. Microbes need both carbon (C) and nitrogen (N), food sources to function. All materials contain both C and N. The ratio of carbon to nitrogen within a material is called the carbon to nitrogen ratio (C:N). Materials with favorable proportions of carbon and nitrogen (C:N) offer the decomposer microorganisms a "complete meal".
"Greens" - Nitrogen Sources - Materials that are a good source of nitrogen are called "Greens" and are characterized as having a low C:N ratio (C:N ratio less than 30:1) and are generally high in moisure and fast to decompose. Examples of "greens" include manure, inorganic fertilizer, vegetable kitchen scraps, green leaves, and grass clippings. Not all "greens" are green in color. For example, coffee grounds are a nitrogen source.
"Browns" - Carbon Source - Materials that are high in carbon relative to nitrogen (i.e., C:N greater than 30:1), are called "Browns", and are generally dry and slow to decompose. They are generally brownish or darker in color. Examples of "browns" include: straw, leaves, chipped branches and tree trimmings, paper, and sawdust. Browns decompose at low temperatures unless combined with a source of nitrogen. Finding a mix of greens and browns that is in balance can be important. The optimum C:N ratio for rapid composting is about 30:1.
(From: http://www.compostinfo.com/tutorial/GreensAndBrowns.htm)
RAPID COMPOSTING:
(from a U.C. Davis publication cited at the end of this section)
Recently, a new method has been developed which corrects some of the problems associated
with the old type of composting. With this process, compost can be made in 2 to 3 weeks....
1. Material will compost best if it is between 1/2 to 1-1/2 inches in size. Soft, succulent tissues need not be chopped in very small pieces because they decompose rapidly. The harder or the more woody the tissues, the smaller they need to be divided to decompose rapidly....
2. For the composting process to work most effectively, material to be composted should have a carbon to nitrogen ratio of 30 to 1. This cannot be measured easily, but experience has shown that mixing equal volumes of green plant material with equal volumes of naturally dry plant material will give approximately a 30/1 carbon to nitrogen (C/N) ratio. Green material can be grass clippings, old flowers, green prunings, weeds, fresh garbage and fruit and vegetable wastes. Dried material can be dead, fallen leaves, dried grass, straw and somewhat woody materials from prunings....
3. Composting works best if the moisture content of materials in the pile is about 50 percent...
4. Heat, which is very important in rapid composting, is supplied by the respiration of the microorganisms as they break down the organic materials. To prevent heat loss and to build up the amount of heat necessary, a minimum volume of material is essential: a pile at least 36" x 36" x 36" is recommended. If less than 32", the rapid process will not occur. Heat retention is better in bins than in open piles, so rapid composting is more effective if bins are used....
5. The compost pile needs to be turned to prevent the pile from getting too hot. if it gets much above 160 o F, the microorganisms will be killed, the pile will cool, and the whole process will have to start from the beginning. By turning the pile it will not overheat, and it will be aerated also, both of which are necessary to keep the most active decomposers functioning. The pile should be turned so that material which is on the outside is moved to the center.... Bins with covers retain the heat better than do those having no covers.... If the material in the pile is turned every day, it will take 2 weeks or a Iittle longer to compost. If turned every other day, it will take about 3 weeks. The longer the interval between turning the longer it will take for the composting to finish....
6. Once a pile is started, do not add anything (with perhaps one exception, which will be mentioned in 9). The reason is that it takes a certain length of time for the material to break down and anything added has to start at the beginning, thus lengthening the decomposition time for the whole pile. Excess material should be as dry as possible during storage until a new pile is started. Moist stored materials will start to decompose and if this occurs, they will not do a good job in the compost pile.
7. Nothing needs to be added to the organic materials to make them decompose. The microorganisms active in the decomposition process are ubiquitous where plant materials are found and will develop rapidly in any compost piles.
8. If done correctly, a pile will heat to high temperatures within 24 to 48 hours. If it doesn't, the pile is too wet or too dry or there is not enough green material (or nitrogen) present. If too wet, the material should be spread out to dry. If too dry, add moisture. If neither of these, then the nitrogen is low (a high C/N ratio) and this can be corrected by adding materials high in nitrogen (such as ammonium sulfate, grass clippings, fresh chicken manure or urine diluted 1 to 5).
9. If the C/N ratio is less than 30/1, the organic matter will decompose very rapidly but there will be a loss of nitrogen. This will be given off as ammonia.... This can be counteracted by the addition of some sawdust.... Sawdust is very high in carbon and low in nitrogen (a high C/N ratio) and therefor will counteract the excess nitrogen. Other than adding water should the pile become dry, this is the only thing which should be added to a pile once it's started....
10. Materials which should not be added to a composting pile include soil, ashes from a stove or fireplace, and manure from carnivorous (meat-eating) animals....Manure from carnivorous animals such as dogs, cats, ... etc., could contain disease-producing organisms that might infect humans. It is not known whether or not the rapid composting process will kill these organisms and therefore such manures should not be used - manure from herbivorous animals such as rabbits, goats, cattle, horses, elephants or fowl can be used....
Cooperative Extension, University of California,Division of Agriculture and Natural Resouces - Leaflet 21251,
PDF format: vric.ucdavis.edu/veginfo/topics/compost/rapidcompost.pdf
OR: http://209.85.215.104/search?q=cache:yBR5-5BEZF4J:vric.ucdavis.edu/veginfo/topics/compost/rapidcompost.pdf+%22rapid+compost%22&hl=en&ct=clnk&cd=3&gl=us
COMPOSTING NON-MEAT KITCHEN SCRAPS:
The biggest difference between kitchen scraps (non-meat) and other plant-based compost materials is the size and toughness of the scraps. A 2002 article from http://compost-bin.com/ discusses simple ways of composting kitchen scraps:
Unlike most yard materials, which are generally, dry, thin, dead or dying, and high in carbon, that is not always the case with kitchen scraps. However, I compost nearly all of my kitchen scraps, including, yes, meat scraps. Food scraps, like some yard materials, just need to be properly prepared, and then added in a reasonable proportion to a properly maintained pile.... [To compost peels like banana and grapefruit (without attached fruit), make sure that the peels are placed] skinside down, and that the peels are evenly distributed. This promotes rapid drying, which is the first step in decomposition. Also note that the pile has been made with a recessed center section. If you do not want people to see what is in your pile, is is easy to cover the food scraps with aged compost. Composting food scraps in this way is very low risk, meaning that there will be minimal if any odor, and it will quickly diminish, especially if the peels are exposed to sunshine.... [In] a slightly more extreme example of food composting, [where] there is actually food and not just peels..., then it would be a good idea to cover food like this with a layer of finished or at least partially finished compost. You could also chop the slices into bits and distribute them evenly on the pile, but this takes more of your time.... [If] large chunks [of foods like pumpkin] have to be dealt with [, note] that they are place skin-side down in the pile. This will encourage moisture to collect in the concave surfaces. Next, it is important that the chunks are placed well towards the interior of the pile, and covered with a layer of aged material. You would not expect something like this to be processed quickly, so be ready to let something like this sit for a couple months before turning the pile.(http://www.compost-bin.com/food.shtml)
COMPOSTING MEAT:
The author of the above Compost-Bin article (http://www.compost-bin.com/food.shtml) has some tips on how to compost meat, which most compost experts advise against:
My first experimentation with this was to throw a raw turkey neck into the middle of a dry leaf pile, just to see what happened. After a day, that pile stunk to high heaven! Big mistake! But I did learn the hard way why most compost resources advise against composting meat.Since then, I have learned to cook the turkey neck and make soup from it, and then, when most of the meat has been stripped, it can be buried deep within a pile in a pocket of aged material. Now I compost chicken bones, T-bones, pork chop bones, etc. with absolutely no problems at all. As long as the meat has been cooked and the bones are free of most meat and fat, when turning time comes I find bones that have been absolutely picked clean. I think this is better than sealing that stuff in plastic and storing it until trash day. My exception is slabs of fat and sometimes poultry skins, though like a thin slice of beef, if a piece of skin is carefully spread out in the center of a pile and covered with aged material then it will be consumed quickly.
COMPOSTING MANURE AND OTHER ANIMAL WASTE:
Although the following article is primarily intended for livestock producers, there is a lot of information that can be extrapolated to small-scale operations, like a single household.
Because of differences in manure characteristics and handling systems for different livestock species, the composting process for each livestock species ... [are] analyzed separately.... Manure from sheep, goats, horses, ducks and others also can be composted by considering their manure characteristics and important factors ...for proper composting. Other organic residues that can be composted include yard wastes, grass clippings, peat moss, sea weeds, fruit and vegetable wastes, food processing wastes, municipal garbage, sewage sludge, etc. When composting any of these materials, consider factors such as air, water content, particle size, C:N ratio, pH and temperature....
http://www.ianrpubs.unl.edu/epublic/pages/publicationD.jsp?publicationId=567
WHAT ABOUT BAD BACTERIA?
Pathogenic (disease causing) bacteria in compost can be a serious health concern. Here are some excerpts from an article addressing this concern. It was published by the California Integrated Waste Management Board:
Composting is an effective means for reducing pathogen concentrations in a variety of organic materials, including manure, yard trimmings, and biosolids (sewage sludge). These materials, when “raw” or not composted, contain pathogens that may infect humans when they are first generated. The pathogens of interest include bacteria, protozoa, viruses, fungi, and helminths (parasitic worms). During the composting process, beneficial microbial populations build up while pathogen concentrations are considerably reduced....
The Composting Process
During composting, beneficial bacteria and fungi use organic feedstock as a source of energy. They grow and reproduce quickly, releasing an enormous amount of heat that warms the compost pile. Under thermophilic (hot) conditions of 135–165°F, biochemical processes accelerate and beneficial microbes quickly deplete the compost of needed oxygen.
For this reason, air must be supplied to an active compost pile by either forcing it in or by periodic turning to maintain air spaces sufficiently large to allow passive ventilation. Operations relying on forced ventilation are called “in-vessel systems” if they are enclosed within a structure and “static pile systems” if they are exposed to the environment.
The majority of compost operations rely on turning to maintain aeration. Because of their long pile shape, these are referred to as “turned windrow systems.” Sustained thermophilic conditions are sufficient to kill most potential human pathogens (as well as most plant pathogens and weed seeds).... Eventually, the compost microbes exhaust the supply of readily available energy in the feedstock. Microbial growth slows and the pile eventually cools to just above ambient temperatures. Supplemental air is no longer necessary, so the compost is allowed to sit undisturbed.
Meanwhile, the microbes slowly consume any odiferous or phytotoxic (poisonous to plants) compounds generated as decomposition by-products and convert them to carbon dioxide and water. This process, called “curing,” generally takes from six weeks to six months. Once compost is properly cured, its organic portion is functionally equivalent to humus and it performs as a safe and useful soil amendment. Curing provides additional time for pathogen destruction....
For an in-vessel or static pile system, compost must reach or exceed 131°F for a continuous three-day period. Turned windrow systems must be maintained at 131°F or higher for 15 days. During this period, windrows must be turned at least five times. Under these conditions, viable pathogens fall below detectable concentrations.... By mixing the composting material, turned windrow systems insure that all portions of the pile are exposed to interior conditions sufficient to kill pathogens. In-vessel and static pile systems are often insulated to insure that exterior temperatures are sufficiently elevated.
While most pathogens are significantly reduced during the composting process, a few may survive. One of these, the fungus Aspergillus fumigatus, is a primary respiratory concern only for certain sensitive individuals exposed during the composting process (rather than an enteric pathogen that may contaminate food crops). Aspergillus fumigatus can infect the lungs of humans when its spores are inhaled. The resulting infection, called “aspergillosis,” is primarily a problem for immuno-compromised individuals, particularly people with low white blood cell counts. Aspergillus fumigatus is not in any way unique to compost. It is very common in the environment, occurring in soils, water, and decaying plant tissues. Matter high in cellulose, such as hay straw, is particularly prone to containing this fungus....
There is a wealth of additional information in this free publication and I highly recommend downloading it and reading the entire thing.
CIWMB Publications Catalog
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Composting Reduces Growers' Concerns about Pathogens
Date Published/Last Revised: October 2000Publication Type: Fact sheetDescription: 4 page(s). Describes some common pathogens found in organic soil amendments, their sources, and how proper composting techniques can eliminate or reduce harmful pathogens. Includes a bibliography and a list of related publications.CIWMB Publication Number: 442-00-014 Cost: $0Downloadable Version (Word 97, 49 KB)
Order a hard copy of this publication.
http://www.ciwmb.ca.gov/Publications/default.asp?pubid=858
COMPOSTING WITH WORMS:
(From the article, "Vermicomposting: Indoor Composting with Earthworms" http://www.franklincountywastedistrict.org/vermicomposting.html )
Composting is usually done outdoors, but the process can easily be adapted for indoor use. So you can compost even if you don't have a yard, or if you don't like going out to a compost bin in the snow, or if you want to produce the highest quality compost there is: vermicompost!
What is vermicomposting?
Vermicomposting is simply composting with earthworms. Earthworms speed up the composting process, aerate the organic material in the bin, and enhance the finished compost with nutrients and enzymes from their digestive tracts. The best kind of earthworms to use are red worms, also known as "red wigglers" and "manure worms". These worms thrive in decomposing organic matter such as leaf piles, compost heaps and old manure piles. They are smaller than nightcrawlers and are reddish brown in color. Red worms are native to Europe but have become naturalized throughout the U.S. Red worms are a good indicator of fertile soil because their presence indicates high organic matter content and a lack of toxic substances in soil.
Red worms make composting indoors feasible because they are very efficient processors of organic waste; they eat and expel their own weight every day. Even a small bin of red worms will yield pounds of rich compost, also known as worm castings. Finished compost can be harvested in as little as two to three months. Redworms are extremely prolific. It takes about three weeks for fertilized eggs to develop in a cocoon from which two or more young worms can hatch. In three months the worms become sexually mature and will start breeding. Within a year you'll be able to give worms away to get a friend started!
Other sources of information on vermicomposting:
(1) http://journeytoforever.org/compost_worm.html
(2) http://www.treehugger.com/files/2007/08/green-basics-vermicompost.php
(3) The following site is still under construction, but looks as if it will be ready soon: http://crazyworms.com/
=================================
A an excellent source source for composting resources:
http://projectcompost.ucdavis.edu/resources.html
COMPOSTING BASICS:
Composting itself is a process whereby microorganisms break down organic materials such as kitchen waste and grass clippings into a rich, earth-like substance called compost or humus. Essentially, any type of plant-material can be composted. There are very few types of non-plant material that are appropriate for composting, and we will discuss these a little later.
The following is information from the Cooperative Extension of the University of California:
A compost is made up of one or more organic materials that have been piled, with or without added soil, and allowed to decompose until the product breaks up readily, can be easily worked into the soil, or can be used as a potting mixture. Organic residues most utilized include leaves, lawn clippings, garden wastes, and animal manures. Because tree trimmings and woody plant stems decay slowly, they should first be chopped or chipped and then composted separately or mixed with other residues. Corn stalks and similar residues should also be chopped before piling. Some detrimental microbes and weed seeds may survive the composting process, so discard diseased plant materials and weeds that have gone to seed....
The process of decay The piled organic materials decompose primarily through the action of bacteria, fungi, and other soil organisms. Crop waste, soil, and dust contain the needed forms which establish themselves quickly under proper conditions for composting. These organisms function more effectively at favorable temperatures, with proper air and moisture, and in the presence of adequate supplies of nutrient elements, especially nitrogen. During decay, excess carbon evolves as carbon dioxide, and nitrogen and other plant nutrient elements become concentrated. The plant materials graduallyturn dark brown to almost black and lose their original structure. Microbial inoculations and other "special preparations" are not necessary for a good product....
(University of California Vegetable Research and Information. Cooperative Extension, University of California.8m-6/79-VL/SL REPRINTED JUNE 1979 LEAFLET 2559)
PDF Format: vric.ucdavis.edu/veginfo/topics/compost/compostprep.pdf
Here are three other sites that have good, simple information on composting basics:
1) http://www.dep.state.pa.us/dep/deputate/airwaste/wm/recycle/compost/Home3.htm
2) http://www.montgomerycountymd.gov/deptmpl.asp?url=/content/dep/composting/basics.asp
3) http://www.compostinfo.com/tutorial/GreensAndBrowns.htm
The third reference (above) discusses "green" and "brown" compost ingredients. Proper proportions of these ingredients are essential in making compost.
Greens and BrownsBackyard Composting is primarily a biological process so you must feed your microorganisms to keep them happy. Microbes need both carbon (C) and nitrogen (N), food sources to function. All materials contain both C and N. The ratio of carbon to nitrogen within a material is called the carbon to nitrogen ratio (C:N). Materials with favorable proportions of carbon and nitrogen (C:N) offer the decomposer microorganisms a "complete meal".
"Greens" - Nitrogen Sources - Materials that are a good source of nitrogen are called "Greens" and are characterized as having a low C:N ratio (C:N ratio less than 30:1) and are generally high in moisure and fast to decompose. Examples of "greens" include manure, inorganic fertilizer, vegetable kitchen scraps, green leaves, and grass clippings. Not all "greens" are green in color. For example, coffee grounds are a nitrogen source.
"Browns" - Carbon Source - Materials that are high in carbon relative to nitrogen (i.e., C:N greater than 30:1), are called "Browns", and are generally dry and slow to decompose. They are generally brownish or darker in color. Examples of "browns" include: straw, leaves, chipped branches and tree trimmings, paper, and sawdust. Browns decompose at low temperatures unless combined with a source of nitrogen. Finding a mix of greens and browns that is in balance can be important. The optimum C:N ratio for rapid composting is about 30:1.
(From: http://www.compostinfo.com/tutorial/GreensAndBrowns.htm)
RAPID COMPOSTING:
(from a U.C. Davis publication cited at the end of this section)
Recently, a new method has been developed which corrects some of the problems associated
with the old type of composting. With this process, compost can be made in 2 to 3 weeks....
1. Material will compost best if it is between 1/2 to 1-1/2 inches in size. Soft, succulent tissues need not be chopped in very small pieces because they decompose rapidly. The harder or the more woody the tissues, the smaller they need to be divided to decompose rapidly....
2. For the composting process to work most effectively, material to be composted should have a carbon to nitrogen ratio of 30 to 1. This cannot be measured easily, but experience has shown that mixing equal volumes of green plant material with equal volumes of naturally dry plant material will give approximately a 30/1 carbon to nitrogen (C/N) ratio. Green material can be grass clippings, old flowers, green prunings, weeds, fresh garbage and fruit and vegetable wastes. Dried material can be dead, fallen leaves, dried grass, straw and somewhat woody materials from prunings....
3. Composting works best if the moisture content of materials in the pile is about 50 percent...
4. Heat, which is very important in rapid composting, is supplied by the respiration of the microorganisms as they break down the organic materials. To prevent heat loss and to build up the amount of heat necessary, a minimum volume of material is essential: a pile at least 36" x 36" x 36" is recommended. If less than 32", the rapid process will not occur. Heat retention is better in bins than in open piles, so rapid composting is more effective if bins are used....
5. The compost pile needs to be turned to prevent the pile from getting too hot. if it gets much above 160 o F, the microorganisms will be killed, the pile will cool, and the whole process will have to start from the beginning. By turning the pile it will not overheat, and it will be aerated also, both of which are necessary to keep the most active decomposers functioning. The pile should be turned so that material which is on the outside is moved to the center.... Bins with covers retain the heat better than do those having no covers.... If the material in the pile is turned every day, it will take 2 weeks or a Iittle longer to compost. If turned every other day, it will take about 3 weeks. The longer the interval between turning the longer it will take for the composting to finish....
6. Once a pile is started, do not add anything (with perhaps one exception, which will be mentioned in 9). The reason is that it takes a certain length of time for the material to break down and anything added has to start at the beginning, thus lengthening the decomposition time for the whole pile. Excess material should be as dry as possible during storage until a new pile is started. Moist stored materials will start to decompose and if this occurs, they will not do a good job in the compost pile.
7. Nothing needs to be added to the organic materials to make them decompose. The microorganisms active in the decomposition process are ubiquitous where plant materials are found and will develop rapidly in any compost piles.
8. If done correctly, a pile will heat to high temperatures within 24 to 48 hours. If it doesn't, the pile is too wet or too dry or there is not enough green material (or nitrogen) present. If too wet, the material should be spread out to dry. If too dry, add moisture. If neither of these, then the nitrogen is low (a high C/N ratio) and this can be corrected by adding materials high in nitrogen (such as ammonium sulfate, grass clippings, fresh chicken manure or urine diluted 1 to 5).
9. If the C/N ratio is less than 30/1, the organic matter will decompose very rapidly but there will be a loss of nitrogen. This will be given off as ammonia.... This can be counteracted by the addition of some sawdust.... Sawdust is very high in carbon and low in nitrogen (a high C/N ratio) and therefor will counteract the excess nitrogen. Other than adding water should the pile become dry, this is the only thing which should be added to a pile once it's started....
10. Materials which should not be added to a composting pile include soil, ashes from a stove or fireplace, and manure from carnivorous (meat-eating) animals....Manure from carnivorous animals such as dogs, cats, ... etc., could contain disease-producing organisms that might infect humans. It is not known whether or not the rapid composting process will kill these organisms and therefore such manures should not be used - manure from herbivorous animals such as rabbits, goats, cattle, horses, elephants or fowl can be used....
Cooperative Extension, University of California,Division of Agriculture and Natural Resouces - Leaflet 21251,
PDF format: vric.ucdavis.edu/veginfo/topics/compost/rapidcompost.pdf
OR: http://209.85.215.104/search?q=cache:yBR5-5BEZF4J:vric.ucdavis.edu/veginfo/topics/compost/rapidcompost.pdf+%22rapid+compost%22&hl=en&ct=clnk&cd=3&gl=us
COMPOSTING NON-MEAT KITCHEN SCRAPS:
The biggest difference between kitchen scraps (non-meat) and other plant-based compost materials is the size and toughness of the scraps. A 2002 article from http://compost-bin.com/ discusses simple ways of composting kitchen scraps:
Unlike most yard materials, which are generally, dry, thin, dead or dying, and high in carbon, that is not always the case with kitchen scraps. However, I compost nearly all of my kitchen scraps, including, yes, meat scraps. Food scraps, like some yard materials, just need to be properly prepared, and then added in a reasonable proportion to a properly maintained pile.... [To compost peels like banana and grapefruit (without attached fruit), make sure that the peels are placed] skinside down, and that the peels are evenly distributed. This promotes rapid drying, which is the first step in decomposition. Also note that the pile has been made with a recessed center section. If you do not want people to see what is in your pile, is is easy to cover the food scraps with aged compost. Composting food scraps in this way is very low risk, meaning that there will be minimal if any odor, and it will quickly diminish, especially if the peels are exposed to sunshine.... [In] a slightly more extreme example of food composting, [where] there is actually food and not just peels..., then it would be a good idea to cover food like this with a layer of finished or at least partially finished compost. You could also chop the slices into bits and distribute them evenly on the pile, but this takes more of your time.... [If] large chunks [of foods like pumpkin] have to be dealt with [, note] that they are place skin-side down in the pile. This will encourage moisture to collect in the concave surfaces. Next, it is important that the chunks are placed well towards the interior of the pile, and covered with a layer of aged material. You would not expect something like this to be processed quickly, so be ready to let something like this sit for a couple months before turning the pile.(http://www.compost-bin.com/food.shtml)
COMPOSTING MEAT:
The author of the above Compost-Bin article (http://www.compost-bin.com/food.shtml) has some tips on how to compost meat, which most compost experts advise against:
My first experimentation with this was to throw a raw turkey neck into the middle of a dry leaf pile, just to see what happened. After a day, that pile stunk to high heaven! Big mistake! But I did learn the hard way why most compost resources advise against composting meat.Since then, I have learned to cook the turkey neck and make soup from it, and then, when most of the meat has been stripped, it can be buried deep within a pile in a pocket of aged material. Now I compost chicken bones, T-bones, pork chop bones, etc. with absolutely no problems at all. As long as the meat has been cooked and the bones are free of most meat and fat, when turning time comes I find bones that have been absolutely picked clean. I think this is better than sealing that stuff in plastic and storing it until trash day. My exception is slabs of fat and sometimes poultry skins, though like a thin slice of beef, if a piece of skin is carefully spread out in the center of a pile and covered with aged material then it will be consumed quickly.
COMPOSTING MANURE AND OTHER ANIMAL WASTE:
Although the following article is primarily intended for livestock producers, there is a lot of information that can be extrapolated to small-scale operations, like a single household.
Because of differences in manure characteristics and handling systems for different livestock species, the composting process for each livestock species ... [are] analyzed separately.... Manure from sheep, goats, horses, ducks and others also can be composted by considering their manure characteristics and important factors ...for proper composting. Other organic residues that can be composted include yard wastes, grass clippings, peat moss, sea weeds, fruit and vegetable wastes, food processing wastes, municipal garbage, sewage sludge, etc. When composting any of these materials, consider factors such as air, water content, particle size, C:N ratio, pH and temperature....
http://www.ianrpubs.unl.edu/epublic/pages/publicationD.jsp?publicationId=567
WHAT ABOUT BAD BACTERIA?
Pathogenic (disease causing) bacteria in compost can be a serious health concern. Here are some excerpts from an article addressing this concern. It was published by the California Integrated Waste Management Board:
Composting is an effective means for reducing pathogen concentrations in a variety of organic materials, including manure, yard trimmings, and biosolids (sewage sludge). These materials, when “raw” or not composted, contain pathogens that may infect humans when they are first generated. The pathogens of interest include bacteria, protozoa, viruses, fungi, and helminths (parasitic worms). During the composting process, beneficial microbial populations build up while pathogen concentrations are considerably reduced....
The Composting Process
During composting, beneficial bacteria and fungi use organic feedstock as a source of energy. They grow and reproduce quickly, releasing an enormous amount of heat that warms the compost pile. Under thermophilic (hot) conditions of 135–165°F, biochemical processes accelerate and beneficial microbes quickly deplete the compost of needed oxygen.
For this reason, air must be supplied to an active compost pile by either forcing it in or by periodic turning to maintain air spaces sufficiently large to allow passive ventilation. Operations relying on forced ventilation are called “in-vessel systems” if they are enclosed within a structure and “static pile systems” if they are exposed to the environment.
The majority of compost operations rely on turning to maintain aeration. Because of their long pile shape, these are referred to as “turned windrow systems.” Sustained thermophilic conditions are sufficient to kill most potential human pathogens (as well as most plant pathogens and weed seeds).... Eventually, the compost microbes exhaust the supply of readily available energy in the feedstock. Microbial growth slows and the pile eventually cools to just above ambient temperatures. Supplemental air is no longer necessary, so the compost is allowed to sit undisturbed.
Meanwhile, the microbes slowly consume any odiferous or phytotoxic (poisonous to plants) compounds generated as decomposition by-products and convert them to carbon dioxide and water. This process, called “curing,” generally takes from six weeks to six months. Once compost is properly cured, its organic portion is functionally equivalent to humus and it performs as a safe and useful soil amendment. Curing provides additional time for pathogen destruction....
For an in-vessel or static pile system, compost must reach or exceed 131°F for a continuous three-day period. Turned windrow systems must be maintained at 131°F or higher for 15 days. During this period, windrows must be turned at least five times. Under these conditions, viable pathogens fall below detectable concentrations.... By mixing the composting material, turned windrow systems insure that all portions of the pile are exposed to interior conditions sufficient to kill pathogens. In-vessel and static pile systems are often insulated to insure that exterior temperatures are sufficiently elevated.
While most pathogens are significantly reduced during the composting process, a few may survive. One of these, the fungus Aspergillus fumigatus, is a primary respiratory concern only for certain sensitive individuals exposed during the composting process (rather than an enteric pathogen that may contaminate food crops). Aspergillus fumigatus can infect the lungs of humans when its spores are inhaled. The resulting infection, called “aspergillosis,” is primarily a problem for immuno-compromised individuals, particularly people with low white blood cell counts. Aspergillus fumigatus is not in any way unique to compost. It is very common in the environment, occurring in soils, water, and decaying plant tissues. Matter high in cellulose, such as hay straw, is particularly prone to containing this fungus....
There is a wealth of additional information in this free publication and I highly recommend downloading it and reading the entire thing.
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Composting Reduces Growers' Concerns about Pathogens
Date Published/Last Revised: October 2000Publication Type: Fact sheetDescription: 4 page(s). Describes some common pathogens found in organic soil amendments, their sources, and how proper composting techniques can eliminate or reduce harmful pathogens. Includes a bibliography and a list of related publications.CIWMB Publication Number: 442-00-014 Cost: $0Downloadable Version (Word 97, 49 KB)
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http://www.ciwmb.ca.gov/Publications/default.asp?pubid=858
COMPOSTING WITH WORMS:
(From the article, "Vermicomposting: Indoor Composting with Earthworms" http://www.franklincountywastedistrict.org/vermicomposting.html )
Composting is usually done outdoors, but the process can easily be adapted for indoor use. So you can compost even if you don't have a yard, or if you don't like going out to a compost bin in the snow, or if you want to produce the highest quality compost there is: vermicompost!
What is vermicomposting?
Vermicomposting is simply composting with earthworms. Earthworms speed up the composting process, aerate the organic material in the bin, and enhance the finished compost with nutrients and enzymes from their digestive tracts. The best kind of earthworms to use are red worms, also known as "red wigglers" and "manure worms". These worms thrive in decomposing organic matter such as leaf piles, compost heaps and old manure piles. They are smaller than nightcrawlers and are reddish brown in color. Red worms are native to Europe but have become naturalized throughout the U.S. Red worms are a good indicator of fertile soil because their presence indicates high organic matter content and a lack of toxic substances in soil.
Red worms make composting indoors feasible because they are very efficient processors of organic waste; they eat and expel their own weight every day. Even a small bin of red worms will yield pounds of rich compost, also known as worm castings. Finished compost can be harvested in as little as two to three months. Redworms are extremely prolific. It takes about three weeks for fertilized eggs to develop in a cocoon from which two or more young worms can hatch. In three months the worms become sexually mature and will start breeding. Within a year you'll be able to give worms away to get a friend started!
Other sources of information on vermicomposting:
(1) http://journeytoforever.org/compost_worm.html
(2) http://www.treehugger.com/files/2007/08/green-basics-vermicompost.php
(3) The following site is still under construction, but looks as if it will be ready soon: http://crazyworms.com/
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A an excellent source source for composting resources:
http://projectcompost.ucdavis.edu/resources.html
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