Transcript 3.5 Food Resources

3.5 Food Resources
Outline the issues involved in the imbalance in global food supply.
•
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Lrabbetts (November 2007) - http://www.slideshare.net/lrabbetts
Compare and contrast the efficiency of terrestrial and aquatic food production systems
• Arable
We eat the
Producers so
little energy is
lost through
transitions
between trophic
levels in the food
chain.
• Livestock
We eat
Consumers that
have eaten
Producers. About
90% Energy is
lost in each
trophic level
transfer.
• Fisheries
Many of the fish
we eat are 2ndary ,
3ary or 4ary
consumers. Also
1ary productivity of
the seas is lower
than land due to
water absorbing
much of the
energy. This leads
to much lower
efficiency.
Compare and contrast the inputs and outputs of materials and energy (energy
efficiency), The system characteristics, and evaluate the relative environmental
impacts of 2 named food production systems
Intensive Beef Farming
USA:
Subsistence Beef Farming
Tanzania:
5. System characteristics
High population density
High inputs to gain high
profits per unit area.
Nomadic, organic
6. Environmental impact
Energy, oil and water
consumption is nonsustainable.
Generally sustainable,
Possibility of over grazing.
1. Inputs of materials
2. Inputs of energy
3.Outputs of materials
4. Outputs of energy
USA
Inputs
Energy…
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Materials…
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Tanzania
USA
Outputs
Energy…
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Energy…
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Materials…
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Materials…
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Tanzania
System Characteristics - USA
Factory farms hold large numbers of animals, typically
cows, pigs, turkeys, or chickens, often indoors, typically
at high densities. The aim of the operation is to produce
as much meat, eggs, or milk at the lowest possible cost.
Food is supplied in place, and a wide variety of artificial
methods are employed to maintain animal health and
improve production, such as the use of antimicrobial
agents, vitamin supplements, and growth hormones.
Physical restraints are used to control movement or
actions regarded as undesirable. Breeding programs are
used to produce animals more suited to the confined
conditions and able to provide a consistent food
product.
The distinctive characteristic of factory farms is the
intense concentration of livestock. At one farm (Farm
2105) run by Carrolls Foods of North Carolina, the
second-largest livestock producer in the U.S., twenty
animals are kept per pen and each confinement building
holds 25 pens.[22] The company's chief executive officer,
F.J. "Sonny" Faison, has said: "It's all a supply-anddemand price question … The meat business in this
country is just about perfect, uncontrolled supply-anddemand free enterprise. And it continues to get more
and more sophisticated, based on science. Only the
least-cost producer survives in agriculture."[23]
http://en.wikipedia.org/wiki/Factory_
farming#cite_note-Scully259-21
“They're in state-of-the-art confinement facilities. The
conditions that we keep these animals in are much more
humane than when they were out in the field. Today they're
in housing that is environmentally controlled in many
respects. And the feed is right there for them all the time,
and water, fresh water. They're looked after in some of the
best conditions, because the healthier and [more] content
that animal, the better it grows. So we're very interested in
their well-being—up to an extent.”[24] F.J. "Sonny" Faison,
Carrolls Foods of North Carolina
Image http://en.wikipedia.org/wiki/File:Confined-animalfeeding-operation.jpg
Cows in a factory farm in the U.S.
22. Scully, Matthew. Dominion, St. Martin's Griffin, pp. 259.
23. Scully, Matthew. Dominion, St. Martin's Griffin, 2002, pp. 255–256.
24. Scully, Matthew. Dominion, St. Martin's Griffin, 2002, p. 258.
System Characteristics - Tanzania
Maasai men and boys herding cattle. Notice the
‘Hump’ on the cows haunches – this is a fatty water
storage organ that makes the cows drought resistant.
• Cows are more valuable than
women! Cows are used for
ceremonial purposes. They are
not killed for their meat but are
bled and milked; the milk and
blood are mixed with a little acid
to make it curdle to provide food.
• Nomadic lifestyle. Herds are
moved from watering hole to
watering hole. The Maasai move
their ‘Bomas’ (mobile villages)
with the herds. When one area is
grazed out they move on. Maasai
are able to supplement their diet
with wild root vegetables and wild
fruits. Many Maasai are now
becoming non-nomadic but still
farm beef cows.
http://i.telegraph.co.uk/multimedia/archive/01209/maasai_1209462c.jpg
Environmental Impacts –USA– Wikipedia
Concentrating large numbers of animals in factory farms is a major contribution to global environmental
degradation, through the need to grow feed (often by intensive methods using excessive fertiliser & pesticides),
pollution of water, soil and air by agrochemicals and manure waste, & use of limited resources (water,
energy).[57]
Livestock production is also particularly water-intensive in indoor, intensive systems. 8% of global human water
use goes towards animal production, including water used to irrigate feed crops.[57]
The animals are generally kept on concrete with slats or grates for the manure to drain through. The manure is
usually stored in slurry form (slurry is a liquid mixture of urine & faeces). During storage on farm, slurry emits
methane & when manure is spread on fields it emits nitrous oxide & causes nitrogen pollution of land & water.
(Organic meat production has a lower
global warming potential per kg than
does intensive meat production.)
“I’m really worried about
this ‘Mad Cow’ disease”
“I’m not; I’m a
Environmental impacts of factory farming can include:
squirrel”
• Deforestation for animal feed production
• Unsustainable pressure on land for production of high-protein/high-energy animal feed
• Pesticide, herbicide and fertilizer manufacture and use for feed production
• Unsustainable use of water for feed-crops, including groundwater extraction
• Pollution of soil, water and air by nitrogen and phosphorus from fertiliser used for feed-crops and from
manure
• Land degradation (reduced fertility, soil compaction, increased salinity, desertification)
• Loss of biodiversity due to eutrophication, acidification, pesticides and herbicides
• Worldwide reduction of genetic diversity of livestock and loss of traditional breeds
• Species extinctions due to livestock-related habitat destruction (especially feed-cropping)
http://en.wikipedia.org/wiki/Factory_farming
Environmental Impacts - Tanzania
The Maasai live in marginal lands. The extra burden of the cattle herds on an already poor
soil conditions can be immense .
1. In drought there is a tendency to overgrazing leading to soil degradation by erosion. As
the Maasai are constantly moving the overgrazing can be spread over a large area.
However the constant movement also allows the soil recovery time (normally 3 months)
before the next grazing period.
2. Lack of agrochemicals means that Nomadic beef farming is completely organic, limiting
chemical degradation. Manure from herd adds nutrients to the soils.
3. Competition with wild-life. The herds directly compete for resources (food, water….)
with herbivores in the marginal lands.
4. Maasai protect their herds against predators. There have been numerous conflicts over
the years between Maasai herdsmen and animal conservation organisations.
For further reading go to:
http://www.maasai-association.org/opinion.html#human
Vadim Onishchenko – Wildlifephoto.org
http://www.wildlife-photo.org/catalog_old/africantribeimages/masaikid-drink-milk-and-blood-avkj7t0545-out.jpg
Discuss the links that exist between social systems and food production systems