Transcript Chapter 12 FOOD, SOIL, AND PEST MANAGEMENT

Chapter 12
FOOD, SOIL, AND PEST MANAGEMENT
GRAINS OF HOPE OR AN ILLUSION?

Vitamin A deficiency in some developing
countries leads to
 Blindness
 Death

1999: Porrykus and Beyer
 Genetically
more iron
engineered rice with beta-carotene and
WHAT IS FOOD SECURITY AND WHY IS IT
DIFFICULT TO ATTAIN?
Many of the poor suffer health problems
from chronic lack of food and poor nutrition,
while many people in developed countries
have health problems from eating too much
food.
 The greatest obstacles to providing enough
food for everyone are poverty, political
upheaval, corruption, war, and the harmful
environmental effects of food production.

MANY OF THE POOR HAVE HEALTH PROBLEMS
BECAUSE THEY DO NOT GET ENOUGH TO EAT
Food security : daily access to enough nuritious
food
 Food insecurity : live with chronic hunger snd
poor nutrition

1
in 6 in developing countries
 Root cause: poverty
MANY PEOPLE SUFFER FROM CHRONIC HUNGER
AND MALNUTRITION

Macronutrients
 Carbohydrates
 Proteins
 Fats

Micronutrients
 Vitamins
 Minerals
MANY PEOPLE SUFFER FROM CHRONIC HUNGER
AND MALNUTRITION

Chronic under nutrition,
hunger ,
 mental retardation,
 stunted growth


Chronic malnutrition:
Goiter in Bangladesh
low protein, high-carbohydrate
 weak, more susceptible to disease, hinders development


Vitamin and mineral deficiencies in people in developing
countries : Iron, Vitamin A, Iodine
KEY NUTRIENTS FOR A HEALTHY HUMAN LIFE
ACUTE FOOD SHORTAGES LEAD TO FAMINES

Famine : severe
shortage of food
 Usually
caused by
crop failures from
Drought
Flooding
War
Mass migration of
starving people to
other areas
War and the Environment:
Starving Children in FamineStricken Sudan, Africa
MANY PEOPLE HAVE HEALTH PROBLEMS FROM
EATING TOO MUCH

Overnutrition : when food energy intake
exceeds energy use and causes excess body fat

Similar health problems to those who are
underfed
 Lower
life expectancy
 Greater susceptibility to disease and illness
 Lower productivity and life quality
FOOD PRODUCTION HAS INCREASED
DRAMATICALLY

Three systems produce most of our food
 Croplands:
grains 77% use 11% of land area
 Rangelands, pastures, and feedlots: 16% ,using
29% of the world’s land area
 Aquaculture: 7%

Importance of wheat, rice, and corn:
 provide
protein

about 47% of the calories , 42% of the
Tremendous increase in global food production
 technological
advancement , machinery
INDUSTRIALIZED CROP PRODUCTION RELIES ON
HIGH-INPUT MONOCULTURES
Industrialized agriculture, high-input agriculture
 uses
heavy equipment and large amounts of
financial capital, fossil fuels, water,fertilizer
 Goal is to steadily increase crop yield
 Plantation
 cash
agriculture: developing countries
crops – bananas, soybeans, sugarcane,coffee,
vegetables on monocultures
SATELLITE IMAGES OF GREENHOUSE LAND
USED IN THE PRODUCTION OF FOOD CROPS
Increased use of greenhouses to raise crops
TRADITIONAL AGRICULTURE OFTEN RELIES ON
LOW-INPUT POLYCULTURES



Traditional subsistence agriculture : human labor and
draft animals, enough food to feed family only
Traditional intensive agriculture : human and draft
animals, fertilizer, water, enough to feed family, sell
some for income
Polyculture : several crops on the same plot, crop
diversity
 Benefits over monoculture
 Slash-and-burn agriculture- clearing in tropical
forests growing a variety of cash crops – 20 types
 mature at different times ,keeps soil covered
SOIL IS THE BASE OF LIFE ON LAND




Soil composition: complex mixture of eroded rock,
mineral nutrients, decaying organic matter, water, air
and billions of living organisms
Soil formation :bedrock subject to mechanical and
chemical weathering and biological processes to form
soil
Layers (horizons) of mature soils
 O horizon: leaf litter
 A horizon: topsoil , humus
 B horizon: subsoil, inorganic matter,
(sand,silt,clay,gravel)
 C horizon: parent material, often bedrock
Soil erosion : water and wind
SOIL FORMATION AND GENERALIZED SOIL
PROFILE
A CLOSER LOOK AT INDUSTRIALIZED CROP
PRODUCTION

Green Revolution: increase crop yields(since 1988)

Monocultures of high-yield key crops
 E.g.,
rice, wheat, and corn
Use large amounts of fertilizers, pesticides, and water
 Multiple cropping


Second Green Revolution -1967. FAst growing dwarf
varieties of rice and wheat . India , China, Central
and South America

World grain has tripled in production
GLOBAL OUTLOOK: TOTAL WORLDWIDE GRAIN
PRODUCTION (WHEAT, CORN, AND RICE)
INDUSTRIALIZED FOOD PRODUCTION IN THE
UNITED STATES
Agribusiness : giant multinational increasingly
control the growing
 Annual sales : more than automative , steel,
housing combined .1/5 of the country’s GDP


Food production: very efficient

Percent of income spent on food : 2% of income
CROSSBREEDING AND GENETIC
ENGINEERING CAN PRODUCE NEW
CROP VARIETIES


Gene Revolution
 Cross-breeding through
artificial selection
 Slow process – 15
years or more to
produce a crop
 Resulting varieties
remain useful for only
5-10 years.
Genetic engineering
 Genetic modified
organisms (GMOs):
transgenic organisms
CROSSBREEDING AND GENETIC ENGINEERING
CAN PRODUCE NEW CROP VARIETIES

Age of Genetic Engineering: developing crops that
are resistant to
Heat and cold
 Herbicides
 Insect pests
 Parasites
 Viral diseases
 Drought
 Salty or acidic soil


Advanced tissue culture techniques
MEAT PRODUCTION AND CONSUMPTION HAVE
GROWN STEADILY

Animals for meat raised in



Pastures
Densely Packed Feedlots
Confined animal feeding
operations

Meat production increased
fourfold between 1961 and
2007

Demand is expected to go
higher as countries become
more industrialized and
incomes increase
FISH AND SHELLFISH PRODUCTION HAVE
INCREASED

Aquaculture, blue
revolution
 World’s fastestgrowing type of
food production
 Raising marine and
freshwater species
in ponds and
underwater cages
 Dominated by
operations that
raise herbivorous
species –
carp,catfish,tilapia
POLY AQUACULTURE

Integrate crop growing and aquaculture by
using rice straw, pig and duck manure to
fertilize farm ponds and rice paddies in order to
produce phytoplankton eaten by various
species of carp
ENVIRONMENTAL PROBLEMS ARISE FROM
FOOD PRODUCTION

Food production in the future may be limited
by its serious environmental impacts, including
soil erosion and degradation, desertification,
water and air pollution, greenhouse gas
emissions, and degradation and destruction of
biodiversity.
Environmental Impacts of food production
Food Production
Biodiversity Loss
Loss and
degradation of
grasslands, forests,
and wetlands
Fish kills from
pesticide runoff
Killing wild predators
to protect livestock
Loss of genetic
diversity of wild crop
strains replaced by
monoculture strains
Soil
Erosion
Water
Water waste
Loss of fertility
Salinization
Waterlogging
Desertification
Aquifer depletion
Increased runoff,
sediment pollution,
and flooding from
cleared land
Air Pollution
Greenhouse gas
emissions (CO2)
from fossil fuel use
Greenhouse gas
emissions (N2O)
from use of
inorganic fertilizers
Human Health
Nitrates in
drinking water
(blue baby)
Pollution from
pesticides and
fertilizers
Algal blooms and
fish kills in lakes and
rivers caused by
runoff of fertilizers
and agricultural
wastes
Greenhouse gas
emissions of
methane (CH4) by
cattle (mostly
belching)
Other air pollutants
from fossil fuel use
and pesticide
sprays
Contamination of
drinking and
swimming water
from livestock
wastes
Pesticide residues
in drinking water,
food, and air
Bacterial
contamination of
meat
Fig. 12-9, p. 286
TOPSOIL EROSION IS A SERIOUS PROBLEM IN
PARTS OF THE WORLD


Soil erosion : movement of soil
components
 Natural causes-wind, water
 Human causesTwo major harmful effects of
soil erosion
 Loss of soil fertility:depletion
of plant nutrients in topsoil
 Water pollution in surface
waters, sediment, residues
of fertilizers and pesticides
Global Soil Erosion
Serious concern
Some concern
Stable or
nonvegetative
Stepped Art
Fig. 12-11, p. 287
DROUGHT AND HUMAN ACTIVITIES ARE
DEGRADING DRYLANDS


Desertification
Moderate: 10-25% drop
Severe : 25-50% drop
Very severe ; more than
50% - gullies, dunes
Effect of global warming
on desertification
increase drought in arid
areas
drop in food production,
Sahel region in W Africa
DESERTIFICATION OF ARID AND SEMIARID
LANDS
CONSEQUENCES OF EXCESSIVE IRRIGATION

Irrigation problems
 Salinization:
accumulation of salts -Asia
 Waterlogging : water accumulates underground and
raises the water table
LIMITS TO EXPANDING THE GREEN REVOLUTIONS

Expansion of the green revolution
 requires huge inputs of fertilizer, pesticide, water,
otherwise yields not much more than traditional crops
 costs too much for subsistence farmers
 Depletion of water, soil salinization, climate change
Solutions
 Irrigating more cropland? 80% increase by 2050
 Cultivating more land? mostly marginal land.
 Using GMOs? increase yield /acre
 Multicropping
INDUSTRIALIZED FOOD PRODUCTION REQUIRES
HUGE INPUTS OF ENERGY

Industrialized food production and consumption have
a large net energy loss
Industrialized Agriculture uses ~17% of All
Commercial Energy Used in the U.S.
GENETICALLY MODIFIED
FOODS
Projected
Advantages
Need less fertilizer
Need less water
More resistant to
insects, disease,
frost, and drought
Grow faster
Can grow in slightly
salty soils
May need less
pesticides
Tolerate higher
levels of herbicides
Higher yields
Less spoilage
Projected
Disadvantages
Irreversible and
unpredictable
genetic and
ecological effects
Harmful toxins in
food from possible
plant cell mutations
New allergens in food
Lower nutrition
Increase in pesticideresistant insects,
herbicide- resistant
weeds, and plant
diseases
Can harm beneficial
insects
Lower genetic
diversity
Fig. 12-16, p. 291
FOOD AND BIO FUEL PRODUCTION SYSTEMS
HAVE CAUSED MAJOR BIODIVERSITY LOSSES



Biodiversity threatened when
 Forest and grasslands are replaced with croplands
 tropical forests and cerrado (savanna) in Brazil
Agrobiodiversity threatened when
 Human-engineered monocultures are used
 Replacing nature’s resilient genetic diversity
 India – 30,000 varieties of rice, now only 10
Importance of seed banks
 Newest: underground vault in the Norwegian Arctic
Producing Fish through Aquaculture Can Harm
Aquatic Ecosystems
Aquaculture
Advantages
Disadvantages
High efficiency
Needs large inputs of
land, feed, and water
High yield in small
volume of water
Can reduce
overharvesting of
fisheries
Large waste output
Can destroy
mangrove forests
and estuaries
Low fuel use
Uses grain to feed
some species
High profits
Dense populations
vulnerable to disease
Fig. 12-18, p. 293
HOW CAN WE PROTECT CROPS FROM PESTS
MORE SUSTAINABLY?

We can sharply cut pesticide use without
decreasing crop yields by using a mix of
cultivation techniques, biological pest controls,
and small amounts of selected chemical
pesticides as a last resort (integrated pest
management).
NATURE CONTROLS THE POPULATIONS OF
MOST PESTS
What is a pest – interferes with human welfare
 Natural enemies—predators, parasites, disease
organisms—control pests

 In
natural ecosystems
 In many polyculture
 agroecosystems
WE USE PESTICIDES TO TRY TO CONTROL
PEST POPULATIONS

Pesticides
 Insecticides
– insects killers
 Herbicides – weed killers
 Fungicides – fungus killers
 Rodenticides – rat and mouse killers

Herbivores overcome plant defenses through
natural selection: coevolution
WE USE PESTICIDES TO TRY TO CONTROL
PEST POPULATIONS
First-generation pesticides-natural chemicals from
plants
 Second-generation pesticides

Paul Muller: DDT Nobel Prize 1948
 Benefits versus harm

Broad-spectrum agents – toxic to many pests and
non-pest species. Chlorinated hydrocarbons: DDT,
organophosphates : malathion, parathion
 Selective or narrow spectrum agents  Persistence – length of time they remain deadly in
the environment for years, biologically magnified in
food webs

INDIVIDUALS MATTER: RACHEL CARSON
Biologist : DDT use
was increasing to
control mosquitoes
 Silent Spring - 1962
 Potential threats of
uncontrolled use of
pesticides
 Gave impetus to the
US environmental
movement

MODERN SYNTHETIC PESTICIDES HAVE
SEVERAL ADVANTAGES

Save human lives prevented deaths from malaria,
typhus and bubonic plague : at least 7 million people

Increases food supplies and profits for farmers
protect 55% of the world’s food supply. Profit $1:$4

Work quickly, long shelf life, easily shipped and
applied

Health risks are very low relative to their benefits

New pest control methods: safer and more effective
MODERN SYNTHETIC PESTICIDES HAVE
SEVERAL DISADVANTAGES

Accelerate the development of genetic resistance, 5
to 10 years, sooner in the tropics

Financial treadmill

Kill natural predators and parasites that help control

Only 0.1-2% of the pesticide applied by aerial or
ground spraying reaches the target pest. Rest
pollutes air, water, harm wild life, affect human
health
MODERN SYNTHETIC PESTICIDES HAVE
SEVERAL DISADVANTAGES



David Pimentel: Pesticide use has not reduced U.S.
crop loss to pests
 Loss of crops is about 31%, even with 33-fold
increase in pesticide use
 High environmental, health, and social costs with
use, $5-10 in damages for every $1 spent
 Use alternative pest management practices could
halve the use of chemical pesticides on 40 major
US crops
Pesticide industry refutes these findings
Campbell soup tomatoes in Mexico, Rice in Indonesia,
Sweden
GLYPHOSATE-RESISTANT CROP WEED
MANAGEMENT SYSTEM: A DILEMMA

Best-selling herbicide (Roundup), Monsanto

Advantages – does not harm living things, degrades
into harmless substances within weeks

Disadvantages - resistant weeds , expensive to develop
other pesticides
CASE STUDY: ECOLOGICAL SURPRISES

1955: Dieldrin sprayed to control mosquitoes

Malaria was controlled

Dieldrin didn’t leave the food chain

Domino effect of the spraying

Happy ending
LAWS AND TREATIES CAN HELP TO PROTECT US
FROM THE HARMFUL EFFECTS OF PESTICIDES

U.S. federal agencies
EPA
 USDA
 FDA

Effects of active and inactive pesticide ingredients
are poorly documented
 Circle of poison, boomerang effect – residues of
banned chemicals exported to other countries may
come back on food, winds carry persistent
pesticides such as DDT

INTERNATIONAL TREATIES
1998 – 50 countries developed treaty that
requires exporting countries to have consent
from importing countries for exports of 22
pesticides , 5 industrial chemicals
 2000 – 100 countries signed to phase out 12
of the most hazardous persistent organic
pollutants (POP’s), 9 of them hydrocarbons
(DDT)
 United States has not signed this agreement








Fool the pest : rotate
crops, adjust plant
times
Provide homes for
pest enemies
Implant genetic
resistance : GMO’s
Bring in natural
enemies : natural
predators
Use insect perfumes
Hormones
Scald them
ALTERNATIVES TO USING
PESTICIDES
INTEGRATED PEST MANAGEMENT IS A
COMPONENT OF SUSTAINABLE AGRICULTURE

Integrated pest
management (IPM)
 Coordinate:
cultivation,
biological controls, and
chemical tools to
reduce crop damage to
an economically
tolerable level

Disadvantages
 expert
knowledge
USE GOVERNMENT POLICIES TO IMPROVE FOOD
PRODUCTION AND SECURITY
Control prices – keep artificially low
 Provide subsidies – price supports, tax breaks,
subsidies for 31% of global farm income

 Developed
: $280 billion /year
 Substitute traditional subsidies with ones that
promote sustainable farming practices
 Subsidies to fishing – promotes destructive fishing
practices

Let the marketplace decide
USE GOVERNMENT POLICIES TO IMPROVE FOOD
PRODUCTION AND SECURITY

United Nations Children’s Fund (UNICEF)
suggests these measures. Can be done at an
average annual cost of $5-10 / child
 Immunizing
children against childhood diseases
 Encourage breast-feeding
 Prevent dehydration in infants and children
 Prevent blindness – Vitamin A capsule (75c/child)
 Provide family planning services
 Increase education for women
HOW CAN WE PRODUCE FOOD MORE
SUSTAINABLY?

Sustainable food production will require
reducing topsoil erosion, eliminating
overgrazing and overfishing, irrigating more
efficiently, using integrated pest management,
promoting agrobiodiversity, and providing
government subsidies for more sustainable
farming, fishing, and aquaculture.
HOW CAN WE PRODUCE FOOD MORE
SUSTAINABLY?

Producing enough food to feed the rapidly
growing human population will require growing
crops in a mix of monocultures and poly
cultures and decreasing the enormous
environmental impacts of industrialized food
production.

Soil conservation,
some methods






Terracing
Contour planting
Strip cropping
with cover crop
Alley cropping,
agroforestry
Windbreaks or
shelterbeds
Conservationtillage farming
No-till
 Minimum tillage


Identify erosion
hotspots
REDUCE SOIL EROSION
SOLUTIONS: MIXTURE OF MONOCULTURE CROPS
PLANTED IN STRIPS ON A FARM
SOIL EROSION IN THE UNITED STATES: DUST
BOWL





Poor cultivation and
prolonged drought
Plowing prairie dug
up root system
Severe wind erosion
Largest internal
migration from the
Midwest
Soil Erosion Act
1935
THE DUST BOWL OF THE GREAT PLAINS, U.S.
RESTORE SOIL FERTILITY


Organic fertilizer
 Animal manure – dung , urine
 Green manure – freshly cut, growing green vegetation
 Compost microorganisms to break down organic waste
Commercial inorganic fertilizer active ingredients
 Nitrogen
 Phosphorous
 Potassium
Crop Rotation
REDUCE SOIL SALINIZATION AND
DESERTIFICATION

Soil salinization



Prevention
Clean-up
Desertification,
reduce




Population growth
Overgrazing
Deforestation
Destructive forms of
planting, irrigation,
and mining
Reduce irrigation
Switch to salttolerant crops (such
as barley, cotton, and
sugar beet
Flush soil
(expensive and
wastes water
Stop growing
crops for 2–5
years
Install
underground
drainage
systems
(expensive)
PRACTICE MORE SUSTAINABLE AQUACULTURE



Open-ocean aquaculture – US developing,
 raising large carnivorous fish in underwater pens
located 300 Km offshore. Fish fattened with fish meal
 Raising shrimp far inland in zero-discharge freshwater
ponds to minimize damage to Florida coastal areas:
salmon, trout, tuna, grouper, cod
 Choose herbivorous fish – carp, tilapia
Polyaquaculture : raise fish, shrimp, algae, seaweeds and
shellfish coastal lagoons
PRODUCE MEAT MORE EFFICIENTLY AND
HUMANELY
Shift to more grain-efficient forms of protein
 Shift to farmed herbivorous fish
 Develop meat substitutes; eat less meat
 Whole Food Markets: more humane treatment
of animals
 World Organization for Animal Health –humane
transportation and slaughter of livestock
animals

EFFICIENCY OF CONVERTING GRAIN INTO
ANIMAL PROTEIN
People food habits changing – eating lower down on the
food chain
SHIFT TO MORE SUSTAINABLE AGRICULTURE

Paul Mader and David Dubois
 22-year
study
 Compared organic and conventional farming

Benefits of organic farming
 little
or no use of synthetic pesticides, fertilizers or
genetically engineered seeds, fields free for 3 years
 livestock raised without genetic engineering
SHIFT TO MORE SUSTAINABLE AGRICULTURE (2)

Strategies for more sustainable agriculture
 Research
on organic agriculture with human
nutrition in mind
 Show farmers how organic agricultural systems
work
 Subsidies and foreign aid
 Training programs; college curricula
SOLUTIONS
Organic Farming
Improves soil fertility
Reduces soil erosion
Retains more water
in soil during
drought years
Uses about 30% less
energy per unit of yield
Lowers CO2 emissions
Reduces water pollution
by recycling livestock
wastes
Eliminates pollution
from pesticides
Increases biodiversity
above and below ground
Benefits wildlife such
as birds and bats
Fig. 12-32, p. 308
SCIENTISTS ARE STUDYING BENEFITS AND
COSTS OF ORGANIC FARMING

Effect of different fertilizers on nitrate leaching
in apple trees
 calcium
nitrate and alfalfa residues, composted
chicken manure, integrated approach (combined)

Less nitrate leached into the soil after organic
fertilizers were used – 4.4 to 5.6 times less
SUSTAINABLE POLYCULTURES OF PERENNIAL
CROPS

Polycultures of perennial crops

Wes Jackson: natural systems agriculture
benefits
 No
need to plow soil and replant each year
 Reduces soil erosion and water pollution
 Deeper roots – less irrigation needed
 Less fertilizer and pesticides needed
COMPARISON OF THE ROOTS BETWEEN AN ANNUAL
PLANT AND A PERENNIAL PLANT
Annual Wheat
Crop Plant
Roots of a tall grass
prairie plant
Better at using
water and nutrients
BUY LOCALLY GROWN FOOD ……………………
Supports local economies
 Does not have to be transported far – reduces
greenhouse gas emissions, 5 to 17 times less
 Reduces environmental impact on food
production – grow organic food or buy organic
food grown locally
 Community-supported agriculture (CSA)

SCIENTIFIC PRINCIPLES OF SUSTAINABILITY
VIOLATED ………………..

Modern industrial agriculture …………….
 depends
on nonrenewable fossil fuels
 too little recycling of crop and animal wastes
 accelerates soil erosion
 does not preserve agro biodiversity
 destroy or degrade wildlife habitat
 disrupt natural species interactions that help to
control pest population sizes
SCIENTIFIC PRINCIPLES OF SUSTAINABILITY
PRESERVED ……………….
rely more on solar energy than oil
 sustaining nutrient cycling by soil conservation
and by returning crop residues and animal
wastes to the soil
 sustain natural /agricultural biodiversity by
relying on a greater variety of crop and animal
strains
 controlling pest populations
 broader use of polyculture and IPM
