Manure
From Wikipedia, the free encyclopedia
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 is trapped by bacteria in the soil. Higher organisms then feed on the fungi and bacteria in a chain of life that comprises the soil food web.
The term "manure" was used for inorganic fertilizers in the past, but this usage is now very rare.[1]
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[edit] Etymology
The word manure came from Middle English "manuren" meaning "to cultivate land," and initially from French "main-oeuvre" = "hand work" alluding to the work which involved manuring land.
[edit] Types
There are two main classes of manures in soil management: green manures and animal manures. Compost is distinguished from manure in that it is the decomposed remnants of organic materials (which may, nevertheless, include manure).
Most animal manure is feces — excrement of plant-eating mammals (herbivores) and poultry — or plant material (often straw) which has been used as bedding for animals and thus is heavily contaminated with their feces and urine. Manure from different animals may have different qualities and require different dosage, common forms of animal manure includes horse manure, cow manure, pig manure, sheep manure, chicken and turkey manures, rabbit manure, seabird and bat guano.[2]
Green manures are crops grown for the express purpose of plowing them under. In so doing, fertility is increased through the nutrients and organic matter that are returned to the soil. Leguminous crops, such as clover, also "fix" nitrogen through rhizobia bacteria in specialized nodes in the root structure.
Other types of plant matter used as manure or fertilizer include: the contents of the rumens of slaughtered ruminants; spent hops left over from making beer.
[edit] Uses of manure
Animal dung has been used for centuries as a fertilizer for farming, as it is rich in nitrogen and other nutrients which facilitate the growth of plants. Liquid manure from pig (hog) operations is usually knifed (injected) directly into the soil to reduce the unpleasant odors. Manure from pigs and cattle is spread on fields using a Manure spreader. Due to the relatively lower level of proteins in vegetable matter, herbivore manure has a milder smell than the dung of carnivores or omnivores – for example, elephant dung is practically odorless. However, due to the quantity of manure applied to fields, odor can be a problem in some agricultural regions. Poultry droppings are harmful to plants when fresh but after a period of composting are valuable fertilizers.
[edit] Precautions
Manure generates heat as it decomposes, and it is not unheard of for manure to ignite spontaneously should it be stored in a massive pile.[3] Once such a large pile of manure is burning, it will foul the air over a very large area and require considerable effort to extinguish. Large feedlots must therefore take care to ensure that piles of fresh manure (faeces) do not get excessively large. There is no serious risk of spontaneous combustion in smaller operations.[citation needed]
There is also a risk of insects carrying feces to food and water supplies, making them unsuitable for human consumption.
[edit] Livestock antibiotics and hormones
In 2007, a University of Minnesota study[4] indicated that foods such as corn, lettuce and potatoes have been found to accumulate antibiotics from soils spread with animal manure that contains these drugs, and organic foods are most likely to contain these drugs because manure is often the main source of crop nutrients for organic food production.
[edit] See also
[edit] Notes
- ^ Ronald Fisher seems to have used the word manure systematically for what we would call fertilizer today.
- ^ http://www.bbc.co.uk/dna/h2g2/A2339624
- ^ Spontaneous combustion of manure starts 200-acre blaze
- ^ Livestock Antibiotics Can End Up in Human Foods
[edit] Further reading
- Anderson, S., and F. Ertug-Yaras. (1998.). "Fuel fodder and faeces: an ethnographic and botanical study of dung fuel use in central Anatolia.". Environmental Archaeology 1: 99–109.
- Charles, M. P. (1998.). "Fodder from dung: the recognition and interpretation of dung derived plant material from archaeological sites". Environmental Archaeology 1: 111–122.
- Fenton, Alexander (1985). "A fuel of necessity: animal manure". Alexander Fenton The Shape of the Past. Essays in Scottish Ethnology: 96-111, Edinburgh: John Donald.
- Miller, N. F. (1984.). "The use of dung as fuel: an ethnographic example and an archaeological application". Paléorient 10: 71–79.
- Winterhalder, B., R. Larsen, and R. B. Thomas. (1974.). "Dung as an essential resource in a highland Peruvian community". Human Ecology 2: 89–104. doi:.
[edit] External links
- Livestock and Poultry Environmental Learning Center, an eXtension community of practice about animal manure management
- Cornell Manure Website
- A two part webcast series about the science available on potential risks and best management practices related to antibiotics and hormones from animal manure
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