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Visualizing Environmental Science
Agriculture and Food
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7
Chapter 14
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Maintaining Grain Stocks for Food Security
• Food security: having access at all times to adequate
amounts and kinds of food needed for healthy, active lives
– World grain stocks provide a
measure of food security
• Grain stocks are grains from
previous harvests which
provide a cushion against poor
harvests and rising costs
• What has been the trend in
grain stocks over the past
three decades?
• UN says it should not be
below a 70 day supply
– The stockpile in 2010 would
only have fed the world for 72
days
© 2014 John Wiley & Sons, Inc. All rights reserved.
World Food Problems
• At least 1 billion people in the world lack food for
healthy, productive lives
– Most live in rural areas of poorest developing countries
• 182 million children under age 5 suffer from
undernutrition
• Undernutrition: a type of malnutrition in which there
is underconsumption of calories or nutrients that
leaves the body weakened and susceptible to disease
• Even if receiving enough calories, undernutrition happens if not
enough essential nutrients: protein, vitamins, and minerals
• 2 billion people worldwide suffer from micronutrient deficiencies
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Where do undernourished people live?
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World’s Undernourished People
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© 2014 John Wiley & Sons, Inc. All rights reserved.
World Food Problems
Millions of children suffer
from kwashiorkor, caused by
severe protein deficiency.
Note the characteristic
swollen belly, which results
from fluid retention.
Photographed in Haiti.
Globally, millions of adult
men and women are hungry.
This homeless man is
suffering from severe
malnutrition and starvation.
Photographed in New Delhi,
India.
Marasmus is progressive
emaciation caused by a diet
low in both total calories and
protein. Symptoms include a
pronounced slowing of
growth and extreme wasting
of muscles. Photographed in
Somalia.
© 2014 John Wiley & Sons, Inc. All rights reserved.
Reasons for Undernutrition & Malnutrition
• Main cause of undernutrition is poverty
– Infants, children, and elderly are most
susceptible to poverty and hunger
– Poorest people do not own land to grow
food and do not have money to purchase
food
• Poverty not restricted to developing
nations
• Solutions:
– Increase sustainable production of food
– Improve food distribution
– Achieve stable population size at a level the
environment can support
https://www.youtube.com/watch?v=r7OSYrveXCw
World Food Problems - Overnutrition
• Overnutrition: a type of
malnutrition in which there
is overconsumption of
calories that leaves the body
susceptible to disease
– Causes: diets high in saturated
fats, sugar, and salt
– Effects: high blood pressure,
obesity, and increased
likelihood of diabetes, heart
disease, etc.
© 2014 John Wiley & Sons, Inc. All rights reserved.
World Food Problems - Overnutrition
• Location: mostly a problem
in highly developed nations
and in urban areas of
developing nations
– As income increases, people
can afford more meats and
sugars, so paradoxically, their
diet can become less healthy
even though they are better
off financially
© 2014 John Wiley & Sons, Inc. All rights reserved.
Annual Meat Consumption
Which vegetables are most
commonly eaten in the U.S.?
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World Food Problems
• Food insecurity: condition in which people live
with chronic hunger and malnutrition
– 22 countries (primarily in sub-Saharan Africa)
commonly experience food insecurity
• 66 countries are considered low income and
food deficient
– Cannot produce enough food, or afford to import it
© 2014 John Wiley & Sons, Inc. All rights reserved.
What percent of U.S. households
are considered “food insecure”?
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U.S. Food Insecurity
• Food-insecure households (those with low and very
low food security) had difficulty at some time during
the year providing enough food for all their members
due to a lack of resources
• In the case of very low food insecurity, the food
intake of some household members was reduced and
normal eating patterns were disrupted at times
during the year due to limited resources
Which states have the highest
prevalence of “food insecurity”?
© 2014 John Wiley & Sons, Inc. All rights reserved.
U.S. Food Insecurity
• Estimated prevalence of food insecurity in
2012-14 ranged from 8.4% in North Dakota to
22.0% in Mississippi
U.S. Food Insecurity
• A major type of food insecurity in the United
States comes from “food deserts”
– An area were populations don’t have access to
fresh foods (ex: they don’t live near a
supermarket)
• http://www.ers.usda.gov/data-products/foodaccess-research-atlas/go-to-the-atlas.aspx
World Food Problems
• Experts agree that world hunger, population,
poverty, and environmental problems are
interrelated
– Solutions:
• control population growth
• promote economic development
• correct inequitable distribution of resources
© 2014 John Wiley & Sons, Inc. All rights reserved.
Global Grain Production
• Annual world grain
production almost doubled
from 1970–2011
– But population has grown
so that amount per person
has not changed
– By 2050, farmers will have
to grow close to 30% more
food to be able to feed the
9.3 billion people expected
– Available grain per person
varies significantly per
country
The Principal Types of Agriculture
• Industrialized agriculture
– Utilized in highly
developed and some
developing countries
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A Concentrated Animal Feeding Operation (CAFO) in Brazil
The Principal Types of Agriculture
• Industrialized agriculture
– Requires large capital and
energy inputs, less land,
and less manual labor
than traditional methods
• Significantly dependent
on fossil fuels
• Produces high yields
• Monoculture cultivation
predominates
• Soil degradation,
pesticide resistance
common
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U.S. Corn Productivity and Land Use
The Principal Types of Agriculture
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The Principal Types of Agriculture
• Subsistence agriculture
– Utilized by most farmers in most developing countries
– Traditional agricultural methods that depend on labor
and a large amount of land
• Just enough food to feed farmer and family
• Cultivation methods vary depending on area
–
–
–
–
–
Shifting cultivation
Slash-and-burn agriculture
Nomadic herding
Intercropping
Polyculture
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Challenges of Agriculture
• U.S. has over 120 million hectares (300 million
acres) of prime farmland
– Has the soil type, growing conditions, available
water to produce food, forage, fiber, oilseed crops
– Challenges
•
•
•
•
Decline in farmland
Declining numbers of domesticated varieties
Continuing to improve crop and livestock yields
Addressing environmental impacts
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Challenges of Agriculture
• Victim of urbanization, suburban sprawl
– Parking lots, housing developments, shopping
malls
• Farm Bill—1996
– Farmland Protection Program
• Voluntary sale of conservation easements to prevent
farmland from being converted to non-agricultural uses
(30 yrs–forever)
• Farmers retain full rights to use their property for
farming
© 2014 John Wiley & Sons, Inc. All rights reserved.
© 2014 John Wiley & Sons, Inc. All rights reserved.
Challenges of Agriculture
• Global decline in domesticated plant and
animal varieties
– Replacement of many local varieties with just a
few kinds of modern varieties bred for uniformity
and maximum production
– Loss of genetic diversity of nutritional value, size,
color, flavor, resistance to disease, adaptability to
climates and soil types
– Germplasm conservation
• Plant or animal material that may be used in breeding
– Seeds, plants, plant tissues of traditional crop varieties
– Sperm and eggs of traditional livestock breeds
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Challenges of Agriculture
• Increasing crop yields
– Scientific advances
since 1940s have
increased food
production
dramatically in highly
developed countries
– Fertilizers, pesticides,
higher yield plant
varieties
Average U.S. wheat yields, 1950-2010
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Challenges of Agriculture
• Green revolution
– 1960s—high yield varieties of rice and wheat developed
• Traditional rice plant on
left—taller, lower grain
yield
• Hybrid in center
(1960s)—higher yield,
disease resistant
• Rice plant on right
(1990s)—high yield,
disease resistant;
shorter and stronger
stalk to support heavier
grain production
without collapsing
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Challenges of Agriculture
• Green revolution
– High yield grain varieties required intensive industrial
agriculture
• In the 1920s, Mexico produced less than 0.7 metric tons/ha
• In 1965, Mexico’s wheat production rose to 2.4 metric
tons/ha
– Criticisms
• Has made developing countries dependent on imported
technologies at the expense of traditional agriculture
– High energy costs
– Environmental problems from excessive pesticide and fertilizer
use
© 2014 John Wiley & Sons, Inc. All rights reserved.
Challenges of Agriculture
• Post-green revolution era
– World’s demand for rice, wheat, corn will continue
to increase into the future
• Increasing amounts of grain needed for humans,
livestock, and biofuel production
– Cannot be met without increasing amount of farmland
– Freshwater shortages, rising costs of agricultural chemicals,
deteriorating soil quality
– Scientists think it’s possible to develop higher yield varieties
with sufficient investment
– Modern agricultural methods must be introduced to
developing countries to increase their crop yields
© 2014 John Wiley & Sons, Inc. All rights reserved.
Challenges of Agriculture
• Increasing livestock yields
– Hormones promote faster growth
• U.S. and Canada farmers use hormones; EU restricts import
– Fear that hormones may affect child development, promote
cancer
• FAO and WHO say hormones found in beef are safe, less
than found in normal human bodies
– Antibiotics improve livestock weight gain, less disease
• Indiscriminate use leads to development of resistant strains
of bacteria—reduces antibiotic efficacy in humans
• WHO recommended elimination of antibiotic use in livestock
– Many European countries have complied; U.S. has not
© 2014 John Wiley & Sons, Inc. All rights reserved.
Environmental Impacts
• Air and water pollution
– Use of fossil fuels and pesticides, animal wastes, fertilizers
• Reduces biodiversity, harms fisheries, outbreaks of nuisance
species
• Replacement of family farms with agribusiness
conglomerates
– Cattle, hogs, poultry grown in feedlots and factories
• Air and water pollution
• Pesticide (toxic chemicals used to kill pests) resistance
– Increasing use of pesticides, residues contaminate food,
kills fish and other aquatic species, reduces beneficial soil
organisms
© 2014 John Wiley & Sons, Inc. All rights reserved.
Environmental Impacts
• Land degradation
– Reduction in the potential ability of the land to
support crops/livestock
– Soil erosion, compaction, salinization
• Habitat fragmentation
– Breakup of large areas of habitat into small,
isolated patches
– Clearing forests, grasslands, draining wetlands
© 2014 John Wiley & Sons, Inc. All rights reserved.
Environmental InSight
• Impacts of industrial agriculture
Increasing antibiotic resistance
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Solutions to Agricultural Problems
• Moving to sustainable agriculture
– Agricultural methods that maintain soil productivity
and a healthy ecological balance while having minimal
long-term impacts
– Also called alternative, or low-input agriculture
– Combines modern with traditional techniques
•
•
•
•
•
Diversification of crops and livestock
Breeding of resistant varieties, to reduce use of chemicals
Water and energy conservation
Crop rotation, conservation tillage to preserve soil quality
Animal manure and leguminous crops to decrease the need
for chemical fertilizers
• Not a single program; adapted to local needs/conditions
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Solutions to Agricultural Problems
• Second green revolution
– Away from high yield, towards long termsustainability
– Options and approaches
•
•
•
•
Organic agriculture
Integrated pest management
Reduction in intensive agricultural techniques
Increasing focus on long-term sustainability of the soil
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Solutions to Agricultural Problems
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EnviroDiscovery
A New Weapon for Locust Swarms
• Locusts periodically increase in number and swarm
across agricultural lands, devastating crops and trees
– In 1998, African farmers spayed massive quantities of
pesticides, but there was great concern about the
adverse ecological and health effects as well as the shortterm costs ($300 million for 1998 swarm)
– Non-chemical biological control was developed in
response—fungal spores that target only locusts
– “Green muscle” environmentally safe and very effective
– In 2009, use of this biological control prevented major
locust infestation in Tanzania
© 2014 John Wiley & Sons, Inc. All rights reserved.
Solutions to Agricultural Problems
• Genetic engineering
– Manipulation of genes to produce a particular effect
• E.g., taking a specific gene from one species and placing it
into an unrelated species
– Revolutionizing agriculture and medicine
– Goals—to develop desirable characteristics in crops
and livestock (= as traditional breeding)
• Has the potential to produce
– More nutritious food plants that contain all essential amino acids
or that would be rich in vitamins
– Resistant to viral diseases, drought, heat, cold, herbicides,
salinity, insect pests, etc.
© 2014 John Wiley & Sons, Inc. All rights reserved.
Potential Benefits of Genetic Engineering
• More nutritious food
• Tastier food
• Disease- and drought-resistant plants that require
fewer environmental resources (such as water and
fertilizer)
• Decreased use of pesticides
• Increased supply of food with reduced cost and longer
shelf life
• Faster growing plants and animals
• Food with more desirable traits, such as potatoes that
absorb less fat when fried
• Medicinal foods that could be used as vaccines or
other medicines
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Genetic Engineering
• A plasmid, a small circular molecule of DNA, introduces
desirable genes from another organism into a plant cell
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Genetic Engineering
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Genetic Engineering
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Genetic Engineering
• First GM crops were approved in the U.S. in early
1990s
– Since 2000, GM production in developing countries
has increased faster than in developed countries
– In 2011, developing countries produced half of the
world’s GM crop
• GM production
– More productive farm animals, fast growing hogs and
fish
– Utilized in the development and production of
vaccines against disease organisms
– Plants can be modified with genes that protect against
insect pests and provide resistance to herbicides
© 2014 John Wiley & Sons, Inc. All rights reserved.
Genetic Engineering
• Concerns about GM foods
• In 1999 EU placed moratorium (since lifted) on approvals for
all GM foods
• EU refused to buy U.S. corn since 80+ percent of U.S. corn is
GM
– Spreading of GM genes to wild relatives of crop plants
may harm natural ecosystems
– Worry that consumers may develop allergies to new
GM foods (even though routinely tested)
– Scientific consensus is that health risks associated
with consuming GM varieties is the same as those of
consuming traditionally bred varieties
– There are still unanswered questions about effects on
environment
© 2014 John Wiley & Sons, Inc. All rights reserved.
© 2014 John Wiley & Sons, Inc. All rights reserved.
AquAdvantage Salmon
• AquAdvantage Salmon has
been genetically engineered
to grow more rapidly than its
non-GE farm-raised Atlantic
salmon counterpart
• It contains rDNA that is
composed of the growth
hormone gene from Chinook
salmon under the control of a
promoter (a sequence of
DNA that turns on the
expression of a gene) from
another type of fish called an
ocean pout
© 2014 John Wiley & Sons, Inc. All rights reserved.
AquAdvantage Salmon
An AquAdvantage® Salmon with a conventionally
grown salmon of the same age
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AquAdvantage Salmon
AquAdvantage® Salmon grows to market-size using
25 percent less feed than traditional Atlantic
salmon on the market today
© 2014 John Wiley & Sons, Inc. All rights reserved.
Labeling of GM Foods
•
•
•
The FDA requires additional labeling of all foods,
including foods from genetically engineered
sources, when the food products are materially
different from their conventional counterparts
“Material differences” include changes in features
(like nutritional profile) and functional properties
The fact that a food is produced through the use of
genetic engineering alone does not normally
constitute a material fact requiring additional
labeling under the Food, Drug, and Cosmetic Act
© 2014 John Wiley & Sons, Inc. All rights reserved.
What do these food labels mean?
• “Natural”
• “Organic”
• “Cage-free”
• “Artisan”
http://abcnews.go.com/blogs/lifestyle/2014/02/natural-vs-organic-how-food-labels-deceive/
© 2014 John Wiley & Sons, Inc. All rights reserved.
Controlling Agricultural Pests
• Pest
– Any organism that interferes in some way with human
welfare or activity
• Some pests compete with us for food, others spread disease
• Pesticide
– The agent used to reduce pest populations
– Can be grouped by target organisms
•
•
•
•
Insecticides
Herbicides
Rodenticides
Fungicides
© 2014 John Wiley & Sons, Inc. All rights reserved.
Controlling Agricultural Pests
• Benefits of pesticides
– Effectively control organisms that spread disease
• Malaria, typhus
– Protect crops from pests and pathogens
• 1/3 of crops are destroyed by pests
– Monocultures (single species grown in large areas)
amplify effect of pests
• Monoculture crops generate very simple ecosystems,
pests thrive, lots of food
• Complex ecosystems with many species will have
predators and parasites that compete with and control
pest populations
© 2014 John Wiley & Sons, Inc. All rights reserved.
Controlling Agricultural Pests
• Problems with pesticides
– Ideal pesticides
• Narrow-spectrum—kills only the intended pest
• Readily breaks down into safe materials
• Does not move around in the environment
– Most pesticides
• Broad-spectrum—kills a variety of organisms, including
beneficial ones
• Do not degrade readily, or break down into other
dangerous materials
• Move around in the environment—enter water, air
© 2014 John Wiley & Sons, Inc. All rights reserved.
Controlling Agricultural Pests
• Problems with
pesticides
– Genetic resistance
• In the 50 years of
wide pesticide use, at
least 520 species of
insects and mites and
at least 84 weed
species have evolved
genetic resistance to
certain pesticides
© 2014 John Wiley & Sons, Inc. All rights reserved.
Controlling Agricultural Pests
• Problems with pesticides
– Bioaccumulation
– Biological magnification
– Natural enemies (beneficial organisms) also die off
from pesticide exposure
• The resulting fewer natural controls for pests leads to
increased pest populations and need for even larger
pesticide use for their control
– Movement of herbicides into water supplies
increases human exposure and slightly elevates
cancer risk
© 2014 John Wiley & Sons, Inc. All rights reserved.
Pesticides
• Bioaccumulation: some pesticides
are found to build-up over time in
the fatty tissues of predators
• Ex: DDT in bald eagles
• When an organism containing
the pesticide is eaten, the
chemical is transferred to the
consumer
• This eventually leads to very
high pesticide concentrations at
high trophic levels
Controlling Agricultural Pests
• Alternatives to pesticides
– Biological controls
• Uses naturally occurring disease organisms, parasites,
or predators to control pests
– Pheromones/hormones
• Natural substance produced by animals to stimulate a
response in other members of the species
– Reproductive controls
– Genetic controls
– Quarantine
– Irradiation
© 2014 John Wiley & Sons, Inc. All rights reserved.
Controlling Agricultural Pests
• Alternatives to
pesticides
– Integrated pest
management (IPM)
• Combination of pest
control methods that if
used in the
right order and at the
proper times, keeps
the pest population
small enough to
prevent substantial
economic loss
© 2014 John Wiley & Sons, Inc. All rights reserved.
Controlling Agricultural Pests
• Integrated pest management
– Combines a variety of methods to control pests
• Management, not eradication of pests
• Farmers need to be educated on how to minimize pest effects
– Important part of sustainable agriculture
– Biological and genetic controls are used as much as
possible
– Conventional pesticides are used sparingly and only if
other methods fail
– Requires thorough knowledge of life cycles and feeding
habits of pests
– Few farmers are using IPM, but number is increasing
• Applying pesticides is simple
• IPM is more complicated, requires more knowledge
© 2014 John Wiley & Sons, Inc. All rights reserved.
Integrated Pest Management (IPM)
Controlling Agricultural Pests
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Case Study
• Organic agriculture
– No usage of commercial inorganic fertilizers or
pesticides
– Organic Food Production Act of 1990
• Specifies guidelines for organic production and labeling
• Federal standards for organic certification went into
effect in 2002
– In 2008, 2 million hectares farmed organically in
the U.S.
– Rapid growth in organic agriculture in U.S. today
© 2014 John Wiley & Sons, Inc. All rights reserved.
Case Study
• Organic agriculture
– Global and U.S. organic agriculture land use and
growth
© 2014 John Wiley & Sons, Inc. All rights reserved.