Food and Agriculture
Chapter 9
Tara Condren & Brian Corset (woops! Briana
Corso
)
Food & Nutrition
Increase in food supplies
corresponding to increase
in human numbers
Past 40 years
Population growth : 1.7%
World Food Production:
2.2%
Not Enough FOOD?!
1960: 60% of residents in
developing countries were
considered
chronically
undernourished
Not even 2,200 kcal per day
(average)!
If today’s food supply was
equitably distributed
2,800 kcal
per person per day
United States: too much food?!
Farmers PAID $$$$$ to NOT grow
crops!
HUNGER
852 million people
–
NOT ENOUGH FOOD
95% chronically undernourished
-
developing
countries
Transition Countries
Bad weather
Poor management
Social crises
Even in rich countries!
FALLING
AGRICULTURAL
PRODUCTION
Poverty
#1 threat to
food security
(ability to
obtain food daily)
Poorest Countries: hunger affects
almost EVERYONE
Other countries: specific
communities/families struggle .
How the family works:
Males
–
largest share & most
nutritious food
Women & children
-
poorest diet
(they need it the most!)
6 million children under 5 die every
year from hunger & malnutrition
The Future
Robert
Fogel
(Nobel Prize
-
winning economist):
Reducing hunger
$120 billion in economic growth
700 million people’s lives would improve
2003 UN World Food Summit
Reducing number of chronically undernourished from 850 million
400 million by 2015
WE ARE OFF TRACK!
47 countries
-
number of chronically underfed people has
INCREASED
Need to recognize the role of women!
50
-
70% of the farming
LAND, CREDIT, EDUCATION, ACCESS to MARKETS
Family
nutrition
FAMINES
Large
-
scale food shortages, massive starvation, social
disruption, and economic chaos
Mass migrations of the starving to refugee camps (food &
medical aid)
2005: 60 million people in 36 countries needed
emergency food aid
2004 Indian Ocean Tsunami
Politics
Economics
Bad Weather
Insect Outbreaks (ex/ the Locusts)
Natural Disasters
Crop
failures &
food
shortages
The RIGHT food!
We need proteins, vitamins, & certain trace minerals
Its not all about the calories!
Malnourishment
-
nutritional imbalance caused by
a lack of specific dietary components or an
inability to absorb or utilize essential nutrients
That’s not healthy!
Poor people cannot afford the
essentials!
FAO: nearly 3 billion (HALF
THE WORLD’S POPULATION
suffer from vitamin, mineral, or
protein deficiencies
Illness & Death OCCUR!
Reduced mental capacity,
developmental abnormalities, &
stunted growth
Mommy was right!
Anemia
Most common nutritional problem in
the world (2 billion people)
Eat more red meat, eggs, legumes &
green veggies!
Iodine Deficiency
Iodine: Synthesis of thyroxin (endocrine
hormone that regulates metabolism &
brain development
Causes goiter, stunted growth, and
reduced mental ability
Iodine added to salt in developed
countries
Goiter: swelling of thyroid
gland at the base of the neck
OFTEN CAUSED BY IODINE DEFICIENCY
There are Vitamins and
Minerals in every bite!
NOT in starchy foods!!!!
Maize (corn), polished rice, and
manioc (tapioca)
-
much of the
poor people’s diet
100
-
140 million children affected
by vitamin A deficiencies
350,000 go blind every year
Folic acid (yes in those dark, green
veggies) are VITAL for early fetal
development
Neurological problems
Microencephaly (small head)
Anencephaly (lacking a brain)
Protein Protein Protein!
Essential to growth & development
Kwashiorkor
-
a young child is displaced
–
and deprived of nutritious breast milk
–
when
a new baby is born
Young children eat cheap starchy food
-
lack
protein
Reddish
-
orange hair, puffy, discolored skin,
bloated belly
Marasmus
Diet low in calories & protein
Thin, shriveled: like a tiny, old, starving person
Let’s talk about obesity!
Rich Countries: 1/3 more calories than needed & too little
exercise
62% of all adult Americans are overweight
1/3 of adults are
obese
(seriously overweight: body mass
greater than 30 kg/m
2
)
Raises your risk of hypertension, diabetes, heart attacks,
stroke, gallbladder disease, osteoarthritis, respiratory
problems, and cancers
300,000 die per year in the USA from obesity
-
related illnesses
1
st
time in history
-
MORE overweight people THAN
underweight!
Trans Fat is not recommended
People will have proper nutrition if they combine this
food pyramid with regular, moderate exercise
The cream of the crop!
Wheat, rice, & corn (maize)
60% of calories consumed by humans come
from wheat & rice
Potatoes, barley, oats, & rye
–
staples in
mountainous regions & high latitudes
Fruits, Vegetables, and Vegetable Oils
High levels of vitamins, minerals, dietary
fiber, and complex carbohydrates
Beef & Milk
Protein
-
rich foods! (Meat & Dairy)
Rise in meat consumption in developing
countries
Increased soybean production in Brazil:
fueled the growth in meat consumption
North American livestock:
Concentrated animal feeding operations
(
CAFOs
):
diet rich in grain, oil & protein
-
fattens animals quickly & produces meat
preferred by many consumers
680 million metric tons of cereals
-
livestock
feed each year
Beef & Milk...continued...
Social & Environmental concerns
Local air & water pollution
500 million metric tons of manure annually
Contaminates groundwater supplies
Respiratory Illnesses
Animal Wastes (ex/hog farms) stored in lagoons
If they leak/rupture
poison local surface water
Deoxygenates the water, kills millions of fish, can
create a “dead zone”
25 million pounds of antibiotics fed to animals in US
Bubba Gump
140 million metric tons of seafood eaten every year
¾ of world’s edible ocean fish, crustaceans, & mollusks
species
-
IN DECLINE!
4 million boats harvesting wild fish exceed sales by $50
billion
Aquaculture (growing aquatic species in net pens or
tanks)
¼ of the world’s seafood
Polyculture systems help reduce aquaculture problems
Ex/ China: ponds & rice paddies to raise fish
FARM POLICY
Rich Countries: pay about $350 billion to their farmers
U.S. Farm Bill: $180 billion in payments over the next ten years for
American farmers
Corn, wheat, cotton, rice & soybeans
Milk, sugar, and peanuts
Subsidies: maintain “family farms”
10% of all farms received 70% of all support
Agricultural Subsidies
Encourage surpluses
American farmers : sell products 20% below actual cost of production
World Trade Organization (WTO) ruled American farm subsidies illegal!
SURPRISE! Case Study Time!
A Soybean Revolution
South America: The Cerrado (savanna Bolivia
Paraguay)
Inexpensive land, new crop varieties, government policies
Red
-
iron rich soils: ACIDIC & poor in nutrients
Humid climate
insects & plant diseases; OH MY!
Lime & Phosphorus
-
4x the previous yield of soybeans, maize, cotton & others
60 million acres planted with soy!
Brazil:
Producing soy for less than half the cost in the U.S.
China: consuming more soy (1/3 of total global soy shipments)
Forest Destruction Crisis
70% of all arable land is owned by less than 3% of the population
74 year old
-
Sister Dorothy Sang shot by gunmen hired by rancher!
Resented her advocacy for native people, workers, and environmental
protection
Soil: A renewable source
Has a terrible reputation!
SOIL
-
complex mixture of
weathered mineral
materials from rocks,
partially decomposed
organic molecules, and a
host of living organisms
Over 15,000 different types
of soils in the U.S.
Parent material, time,
topography, climate &
organisms on soil formation
It’s a mixture!
Soil:
Half mineral; the rest: plant &
animal residue, air, water & living
organism
Particle size affects the soil!
Ex/ heavy VS light soil
Heavy: high clay content
Light: mostly sand or silt
Sandy loam: best cultivating soil!
Majority of organic material in
soil:
Humus: sticky, brow, insoluble
residue from partially
decomposed bodies of dead
plants & animals
Develops the structure of soil
Living Organisms’ Importance
Create structure, fertility, & tilth!
Soil organism: close to surface
Thousands of species & billions of individual organisms
1 gram of soil: hundreds of millions of microscopic cells
What smells so good?!
Actinomycetes
-
bacteria that grow in fungus like strands &
give us the antibiotics streptomycin & tetracyclines
Micorrhizal Symbiosis
Roots & fungi
Crazy Animals!
Mind the Worms!
Animals be wildin!
Soils are Layered
Most soils are stratified into horizontal layers called soil horizons
They reveal much about the history and usefulness of the soil
Soil profile
The thickness, color, texture, and composition of each horizon are
used to classify the soil
The soil surface is covered with a layer of leaf litter, crop residues, or
other decomposed organic material
This is known as the O horizon
Topsoil
Below the O horizon
Composed of mineral particles mixed with organic material
Regolith
It is beneath the subsoil
Made of weathered rock fragments with very little organic material
Soils are classified according to
their structure and composition:
In the United States, soils are classified into 12 soil orders:
Mollisols
and
alfisols
Spodosols
Oxisols
and
ultisols
Aridosols
Andisols
Vertisols
Histosols
Entisols
and
inceptisols
Gelisols
WAYS WE USE AND ABUSE SOIL
Only about 12.5% of the earth’s land area is currently in
agricultural production
Parts of the world lack suitable soil, topography, water, or
climate to sustain our levels of productivity
The cropland available for agriculture is shrinking
1970
-
global average of 0.38 ha per person
2002
-
0.21 ha per person
2030
-
0.16 ha per person
Asia
-
30 years from now
-
0.09 ha per person
The largest increases in cropland over the last 30 years
occurred in South America and Oceania where forests and
grazing lands are rapidly being converted to farms
Land degradation reduces
agricultural potential
The International Soil Reference and Information Centre
in the Netherlands estimates that every year 3 million ha
of cropland are ruined by erosion, 4 million ha are
turned into deserts, and 8 million ha are converted to
nonagricultural uses such as homes and highways
We generally consider the land degraded when the soil is
impoverished or eroded, water runs off or is
contaminated more than is normal, vegetation is
diminished, biomass production is decreased, or wildlife
diversity diminishes
Water and wind erosion provide the motive force for the
vast majority of all soil degradation, worldwide
Soil erosion is widespread
Erosion is an important natural process, resulting in
the redistribution of the products of geologic
weathering, and is part of both soil formation and
soil loss
Erosion is a disaster only when it occurs in the
wrong place at the wrong time
The total annual soil loss from croplands is thought
to be 25 billion metric tons
About twice that much soil is lost from rangelands,
forests, and urban construction sites each year
Wind and water are the main
agents that move soil
A thin layer taken off the land surface is called sheet erosion
Rill erosion
-
the process when little rivulets of running water gather together and cut small
channels in the soil
Most soil loss on agricultural land is sheet or rill erosion
Summer dust storms in the Sahara Desert of North Africa carry about 1 billion tons of soil in
massive airborne dust plumes over the Atlantic and Mediterranean every year
Some of the highest erosion rates in the world occur in the United States and Canada
Intensive farming practices are largely responsible for this situation
Row crops, such as corn and soybean, leave soil exposed for much of the growing season
Continuous monoculture cropping can increase soil loss tenfold over other farming patterns
Soil study in Iowa showed that a three
-
year rotation of corn, wheat, and clover lost an
average of only 6 metric tons per hectare
Deserts are spreading
around the world
According to the United Nations, about one
-
third of the earth’s
surface and the livelihoods of at least one billion people are
threatened by desertification
Contributes to food insecurity, famine, and poverty
Rangelands and pastures, which generally are too dry for
cultivation, are highly susceptible to desertification
80% of the world’s grasslands are suffering from overgrazing
and soil degradation, and three
-
quarters of that area has
undergone some degree of desertification
China is trying to fight the spread of deserts with an ambitious
ecological restoration program
Since 1985, more than 40 billion trees have been planted
over an area the size of Germany
OTHER AGRICULTURAL
RESOURCES
All plants need water to grow
Agriculture accounts for the largest single share of global water use
About two
-
thirds of all fresh water withdrawn from rivers, lakes, and
groundwater supplies is used for irrigation
Farmers often tend to over
-
irrigate because water prices are relatively low and
because they lack the technology to meter water and distribute just the amount
needed
In the United States and Canada, many farmers are adopting water
-
saving
technologies such as drip irrigation or downward
-
facing sprinklers
Excessive use not only wastes water; it often results in water
-
logging
Waterlogged soil is saturated with water, and plant roots die from lack of
oxygen
Salinization
occurs particularly when soils in dry climates are irrigated with
saline water
Plants need fertilizer
In addition to water, sunshine, and carbon dioxide, plants need
small amounts of inorganic nutrients for growth
The major elements required by most plants are nitrogen,
potassium, phosphorus, calcium, magnesium, and sulfur
Farmers may over fertilize because they are unaware of the
specific nutrient content of their soils or the needs of their crops
What are some alternative ways to fertilize crops?
Manure and green manure (crops grown specifically to add
nutrients to the soil) are important natural sources of soil
nutrients
Interplanting
or rotating beans or some other leguminous crop
with such crops as corn and wheat are traditional ways of
increasing nitrogen availability
Farming consumes energy
Farming as it is generally practiced in the industrialized countries is
highly energy
-
intensive
Fossil fuels supply almost all of this energy
After crops leave the farm, additional energy is used in food
processing, distribution, storage, and cooking
It has been estimated that the average food item in the American diet
travels 2,000 km between the farm that grew it and the person who
consumes it
Altogether the food system in the United States consumes about 16%
of the total energy we use
Farmers could assist in moving to a renewable energy future by
growing energy crops that can be converted into
biofuels
Encouraged construction of corn
-
or soy
-
based ethanol factories
Mixing ethanol with gasoline helps reduce air pollution
NEW CROPS AND
GENETIC ENGINEERING
Many new or unconventional varieties might be
valuable human food supplies, especially in areas
where conventional crops are limited by climate,
soil, pests, or other problems
Winged bean
A perennial plant that grows in hot climates
Edible, resistant to diseases, and enriches the soil
Tricale
A hybrid between wheat and rye that grows in
light, sandy, infertile soil
The “green revolution” produced
dramatic increases in crop yields
A century ago, when all corn in the United States was open
-
pollinated,
average yields were about 25 bushels per acre
In 1999, average yields from hybrid maize were around 130 bushels
per acre
Most of this gain was accomplished by conventional plant
breeding
Geneticists laboriously hand
-
pollinating plants, moving selected genes
from one variety to another
Starting about 50 years ago, agricultural research stations began to
breed tropical wheat and rice varieties that would provide food for
growing populations in developing countries
It is one of the main reasons that world food supplies have more
than kept pace with the growing human population over the past
few decades
Poor farmers who can’t afford the expensive seed, fertilizer, and water
required to become part of this movement, usually are left out of the
green revolution
May be driven out of farming altogether
Genetic engineering uses molecular
techniques to produce new crop varieties
Genetic engineering
Involves removing genetic material
from one organism and splicing it
into the chromosomes of another
Has the potential to greatly increase
both the quantity and quality of our
food supply
It is now possible to build entirely new
genes, and even new organisms
GMOs
(genetically modified organisms
Research is now underway to improve
yields and create crops that resist
drought, frost, or diseases
Genetic Engineering
Continued
Other strains are being developed to tolerate salty, waterlogged, or low
-
nutrient soils
All of these could be important for reducing hunger in developing countries
Plants that produce their own pesticides might reduce the need for toxic chemicals
Attempts to remove specific toxins or allergens from crops also could make our food
safer
Crops such as bananas and potatoes have been altered to contain oral vaccines that can
be grown in developing countries where refrigeration and sterile needles are
unavailable
It may soon be possible to create animals with human cell
-
recognition factors that could
serve as organ donors
Opponents
-
could create a host of problems, some of which we can’t even
imagine
GMO’s
might escape and become pests or they might interbreed with wild relatives
This technology may be available only to the richest countries or the wealthiest
corporations, making family farms uncompetitive and driving developing countries
even further into poverty
About 82% of all soybeans, 71% of the cotton, and one
-
quarter of all corn grown in the
United States are
GMOs
Most
GMOs
have been engineered for
pest resistance or weed control
Biotechnologists recently have created plants with
genes for endogenous insecticides
Allows farmers to reduce insecticide spraying
Arizona cotton farmers report reducing their use of
chemical insecticides by 75%
Is genetic engineering
safe?
In 2002, while millions of its people faced famine, Zambia’s
government refused to accept thousands of tons of genetically
modified corn from the United States, claiming that it might be
unsafe for human consumption
Most European nations have bans on genetically engineered
crops
The first genetically modified animal designed to be eaten by
humans is an Atlantic salmon containing extra growth
hormone genes from an oceanic pout
Greatest worry: the ecological effects if the fish escape from
captivity
People argue that the government should be more careful
when it comes to genetically engineered animals
SUSTAINABLE
AGRICULTURE
Sustainable agriculture
Regenerative farming, or
agroecology
, all of
which aim to produce food and fiber on a
sustainable basis and repair the damage caused
by destructive practices
Soil conservation is
essential
Soil is a renewable resource that can be replenished and
renewed indefinitely
There is evidence that American soil conservation
programs are having a positive effect
Water runoff can be reduced by leaving grass strips in
waterways and by contour plowing
Plowing across the hill rather than up and down
Strip farming
Planting of different kinds of crops in alternating strips along the
land contours
When one crop is harvested, the other is still present to protect the soil
and keep water from running straight downhill
Terracing
Involves shaping the land to create level shelves of earth to hold water
and soil
This is an expensive procedure, requiring either much hand labor or
expensive machinery
Soil Conversion Continued
Providing Ground Cover
Annual row crops such as corn or beans generally cause the highest
erosion rates because they leave soil bare for much of the year
Cover crops
Mulch
Reduced Tillage
Finding that less plowing and cultivation often makes for better
water management, preserves soil, saves energy, and increases crop
yields
There are several major reduced tillage systems
Minimum till involves reducing the number of times a farmer disturbs the soil
by plowing, cultivating, etc
Often involves a disc or chisel plow rather than a traditional moldboard plow
No
-
till planting is accomplished by drilling seeds into the ground directly
through mulch and ground cover
Soil
Cover
and
Soil
Erosion
Cropping System
Average Annual Soil Loss
(Tons/Hectare)
Percent Rainfall Runoff
Bare soil (no crop)
41.0
30
Continuous corn
19.7
29
Rotation: corn, wheat, clover
2.7
23
Continuous bluegrass
0.3
12
Low
-
input agriculture can
be good for farmers and
their farms
Some farmers are going back to a more natural,
agroecological
farming style
Antibiotics are used only to fight diseases
Low
-
input farms typically don't turn out the
quantity of meat or milk that their intensive
agriculture neighbors do, but their production
costs are lower, and they get higher prices for
their crops
THE END!
nomnomnomnomnom
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