Get documents about "PowerPoint Presentation - Food_ Soil_ and Pest Management
Shared by: hcj
-
Stats
- views:
- 27
- posted:
- 4/5/2012
- language:
- English
- pages:
- 66
Document Sample
Food, Soil, and Pest
Management
Chapter 10
Brittany, Carly, and Emma
Key Concepts
How is food produced?
Green Revolutions and traditional farming
Soil degradation and erosion
Increasing food production
Malnutrition
Environmental impacts of food production
Impacts of government policies on food production
Sustainable agriculture
Would You Eat Winged Beans
and Bug Cuisine?
People need protein
Poor can’t afford meat
Environmental impacts of livestock
Winged bean
Microlivestock
• Edible insects
Why bugs are not popular food
Fig. 10-2, p. 206
Caterpillars as Food
•An example: Mopani
•Emporer moth caterpillar
•So popular in South America,
being overharvested
Beneficial:
•Consuming more reduces
malnutrition
•Lessens large environmental impact
of producing forms of meat
•Low carbohydrates, low fat sources,
and 58-78% protein— 3 to 4 times
the level found in chicken, eggs, fish,
beef, etc.
Fig. 10-1, p. 206
Food Production
Major food sources (3): croplands, rangelands, and oceans
Large increase in food production since 1950
Need for environmental-friendly food production
Impact of genetic engineering
Problem of poverty
Primary crops: wheat, corn, and rice
Primary meat sources: fish, chicken, pigs, and cattle
Types of Agriculture
Two major types of agricultural systems: industrialized
and traditional
Industrialized (high-input) agriculture
• Monocultures (single crop), ¼ of all cropland, and developed countries
Plantation agriculture (form of industrialized)
• Large monocultures, tropical developing countries (grown)
• Ex- bananas, soybeans, sugarcane, cocoa, and vegetables
Traditional intensive agriculture
• Increase human labor, fertilizer and water- to produce enough to feed families and sell for
income
Traditional subsistence agriculture
• Only enough for families survival
Principal Types of Food Production
Industrialized agriculture Plantation agriculture Intensive traditional agriculture
Shifting cultivation Nomadic herding No agriculture Fig. 10-3, p. 208
Ecological and Economic
Services of Croplands
Natural Capital
Croplands
Ecological Economic
Services Services
•Help maintain water flow and •Food crops
soil infiltration
•Provide partial erosion protection •Fiber crops
•Can build soil organic matter
•Crop genetic
resources
•Store atmospheric carbon
•Provide wildlife habitat for some •Jobs
species
Fig. 10-4, p. 209
Food Production in the Green
Revolution
Develop plant monocultures
High yields with fertilizers, pesticides, and water
Multiple cropping
First and second revolutions
Environmental impacts
Energy use
Green Revolutions
First green revolution Second green revolution Major international agricultural
(developed countries) (developing countries) research centers and seed banks
Fig. 10-5, p. 210
US Agriculture
Agribusiness
• Industrialized farming evolved into- big companies take control of ¾
U.S. food production
Highly productive
• 18% nations gross domestic product. 1/5 of all jobs in private sector (
employs more than any other industry)
• U.S. produces 17% of world’s grains
Greatly increased yields under Green Revolution
Very efficient
Energy intensive
Energy Use in US Agriculture
17% of total
4% 2% 6% 5% commercial
energy use
Crops Livestock Food processing Food distribution and preparation
Food production
Fig. 10-7, p. 211
Traditional Agriculture
Interplanting- several crops on same plot simultaneously
Polyvarietal cultivation- plot with several genetic varieties
of same crop
Intercropping- 2 or more different crops grown at same time on
a plot
• Ex- carbohydrate rich grain that uses soil nitrogen and a nitrogen fixing
plant that outs it back (like a support system or a balancer)
Agroforestry or alley cropping- crops and tress grown
together
Polyculture- many different plants maturing at various times are
planted together
World Grain Production
Fig. 10-17, p. 218
Causes of Hunger and
Malnutrition
Poverty
Inequality
War
Corruption
Nutrition
Undernutrition- people who cannot grow or buy
enough food to meet basic energy needs
Malnutrition- results from deficiencies of protein,
calories, and other key nutrients
Overnutrition- food energy intake exceeds energy use
and causes excess body fat
Micronutrient
Deficiencies
Vitamin A
Iron and anemia
Iodine
Saving Children from
Malnutrition and Disease
Immunizations against diseases
Encouraging breast feeding (except for mothers with
AIDS)
Prevent dehydration from diarrhea
Prevent blindness with vitamin A
Family planning
Increase education for women
Consequences of
Overnutrition
Lower life expectancy
Greater susceptibility to disease
Lower productivity and life quality
Obesity and overweight
Leading cause of premature death
Serious problem in the US
Possible solutions
Environmental Effects of
Producing Food
Environmental degradation may
decrease future food production
Almost 30% of world’s cropland
degraded
Environmental degradation may limit
food production in India and China
Major Environmental Effects of
Food Production
Fig. 10-18a,b, p. 220
Soil Erosion and Degradation
Land degradation
Soil erosion: flowing water and wind
Erosion enhanced by humans
Gully erosion
Loss of soil fertility
Global soil erosion
Soil Erosion on Irrigated
Cropland
Fig. 10-8, p. 212
Gully Erosion
Fig. 10-9, p. 212
Global Soil Erosion
Areas of serious concern
Areas of some concern
Stable or nonvegetative areas
Fig. 10-10, p. 213
Soil Erosion in the US
US soils eroding 16 times faster than forming
Great Plains lost 1/3 or more of their topsoil
Reductions in US soil losses since 1980s
Desertification
Soils dry out, degrade, and become less fertile
Natural causes
Human contributions
World Desertification
Moderate Severe Very Severe
Fig. 10-11, p. 214
Causes and Consequences of
Desertification
Causes Consequences
Overgrazing
Worsening drought
Deforestation
Famine
Erosion
Economic losses
Salinization
Lower living
Soil compaction standards
Natural climate Environmental
change refugees
Fig. 10-12, p. 215
Salinization and Waterlogging of
Soils
Impacts of irrigation
Salt accumulation in soils (salinization)
Salts kill crops and make soils infertile
Prevention is cheaper than remediation
Waterlogging: accumulation of saline water
Salinization and Waterlogging in Soils
Transpiration
Evaporation
Evaporation Evaporation
Waterlogging
Less permeable
clay layer
Fig. 10-13, p. 215
Salinization from Heavy
Irrigation
Fig. 10-14, p. 215
Preventing and Cleaning Up Soil
Salinization
Solutions
Soil Salinization
Prevention Cleanup
Reduce irrigation Flushing soil
(expensive and
wastes water)
Not growing crops
for 2-5 years
Switch to salt-
tolerant crops
(such as barley, Installing under-
cotton, sugar beet) ground drainage
systems (expensive)
Fig. 10-15, p. 215
Conservation Tillage
Soil conservation
Conservation-tillage farming
• Minimum-tillage farming
• No-till farming
Terracing
Fig. 10-16a, p. 217
Contour Planting and Strip Cropping
Fig. 10-16b, p. 217
Alley Cropping
Fig. 10-16c, p. 217
Windbreaks
Fig. 10-16d, p. 217
Organic Fertilizers
Animal manure
Green manure
Compost
Crop rotation
Inorganic Fertilizers
Commercially available
Nitrogen
Phosphorus
Potassium
Doesn’t replace organic matter
Increasing Food Production
Traditional crossbreeding
Genetic engineering (Third Green Revolution)
Genetically modified foods (GMF)
Expanding the Green Revolution
Environmental impacts
Limits of the Green Revolution
Irrigation
Limits to expansion of cultivatable land
Tradeoffs of Genetically Modified
Foods
Trade-Offs
Genetically Modified Food and Crops
Projected Projected
Advantages Disadvantages
Need less fertilizer Irreversible and
unpredictable genetic
Need less water and ecological effects
More resistant to insects, Harmful toxins in food
plant disease, frost, and From possible plant cell
drought Mutations
Faster growth New allergens in food
Can grow in slightly salty Lower nutrition
soils
Increased evolution of
Less spoilage Pesticide-resistant
Insects and plant
Better flavor disease
Less use of conventional Creation of herbicide-
pesticides Resistant weeds
Tolerate higher levels of Harm beneficial insects
pesticide use
Lower genetic diversity
Higher yields
Fig. 10-19, p. 221
Producing More Meat
Feedlots
Environmental impacts
Water use and contamination
Soil loss from overgrazing
Cattle methane and soil nitrous oxide: greenhouse gases
Contamination from animal wastes
Overgrazing and desertification
Endanger wildlife
Sustainable meat production
Overgrazed and Lightly Grazed
Rangeland
Fig. 10-20, p. 223
Efficiency of Converting Grain
into Animal Protein
Kilograms of grain needed per kilogram of body weight
Beef cattle
7
Pigs
4
Chicken
2.2
Fish (catfish
or carp) 2
Fig. 10-21, p. 224
Harvesting Fish and Shellfish
Fisheries
Fishing methods
Aquaculture
World fish catch
Overfishing
Commercial extinction
Aquaculture (fish farming and ranching)
Sustainable aquaculture
Fishing Methods
Spotter airplane
Fish farming Trawler
in cage fishing
sonar
Purse-seine fishing
trawl flap
trawl
lines
fish school
trawl bag
Drift-net fishing
Long line fishing float buoy
lines with
hooks
fish caught
by gills
Fig. 10-22, p. 225
Fish Catch
Fig. 10-23a, p. 225
Tradeoffs of Aquaculture
Trade-Offs
Aquaculture
Advantages Disadvantages
Highly efficient Large inputs of land, feed,
And water needed
High yield in small
volume of water Produces large and
concentrated outputs of
Increased yields waste
through cross-
breeding and genetic Destroys mangrove forests
engineering
Increased grain production
Can reduce over- needed to feed some
harvesting of species
conventional fisheries
Fish can be killed by
Little use of fuel pesticide runoff from
nearby cropland
Profit not tied to price
of oil Dense populations
vulnerable to disease
High profits
Tanks too contaminated to
use after about 5 years
Fig. 10-24, p. 226
Solutions: More Sustainable
Aquaculture
Solutions
More Sustainable Aquaculture
• Reduce use of fishmeal as a feed to reduce depletion
of other fish
• Improve pollution management of aquaculture
wastes
• Reduce escape of aquaculture species into the wild
• Restrict location of fish farms to reduce loss of
mangrove forests and other threatened areas
• Farm some aquaculture species (such as salmon and
cobia) in deeply submerged cages to protect them
from wave action and predators and allow dilution of
wastes into the ocean
• Set up a system for certifying sustainable forms of
aquaculture
Fig. 10-25, p. 227
Effects of Government Agricultural
Policies on Food Production
Protecting US agriculture
Keeping food prices artificially low for consumers
Subsidies and tax breaks for farmers
Eliminate government supports?
Food aid
Reward farmers if they protect the environment?
Pests
Compete with humans for food
Invade lawns and gardens
Destroy wood in houses
Spread disease
Invade ecosystems
Simply a nuisance
May be controlled by natural enemies
Humans too often destroy the natural enemies of pests
Spiders: Enemies of Insect Pests
Fig. 10-26, p. 227
Pesticides
Chemicals to kill or control undesirable organisms
Insecticides
Herbicides
Fungicides
Rodenticides
Biocides
Toxicity and use
Broad- and narrow-spectrum agents
Persistence
Rachel Carson
•Pioneer in increasing public
awareness of the importance
of nature and threat of
pollution from pesticides
•Wrote The Sea Around Us
about the natural history of
oceans and how human
activities were harming them
•In 1962, published Silent
Spring about affects of
pesticides
•An important contributor to
the modern environmental
movement in the U.S.
Fig. 10-A, p. 229
The Case for Pesticides
Save human lives
Increase food supplies and lower costs for consumers
Profitable for farmers
Work faster and better than alternatives
When used properly, benefits exceed health risks
Newer pesticides are safer and more effective than older ones
Newer pesticides have low application rates
The Ideal Pesticide
Kills only target pest
Doesn’t cause genetic resistance in the target
organism
Disappears or breaks down into harmless
components after doing its job
More cost-effective than doing nothing
The Case Against Pesticides
Accelerate genetic resistance in pests
The pesticide treadmill
Kill the pests’ natural enemies
Don’t say put: pollute
May harm wildlife
May threaten human health
How successful are pesticides?
US Pesticide Regulations
US EPA has banned some pesticides
Food Quality Protection Act
Problems with federal laws on pesticide use and enforcement
Besides EPA, FDA and USDA also regulate pesticide use
Exporting banned pesticides from the US
Alternatives to Chemical
Pesticides
Adjusting cultivation practices
Genetic engineering
Biological control (use of natural predators)
Sex attractant (pheromone) traps
Hormones to disrupt the insect life cycle
Hot water
Genetic Engineering to Reduce
Pest Damage
Fig. 10-28, p. 232
Integrated Pest Management
Ecological system approach
Reduce pest populations to economically tolerable levels
Biological and cultivation methods first used
Chemical pesticides are a last resort
Results in Indonesia
Pollution prevention and other advantages
Disadvantages of integrated pest management
Methods for promoting integrated pest management in the US
Why is Integrated Pest Management
Not More Widely Used?
Requires expert knowledge
Initial costs may be high
Hindered by government subsidies
Opposition from pesticide companies
Solutions: Sustainable Agriculture
Slow population growth
Reduce poverty
Sustainable (low-input or organic) agriculture
Increase research on sustainable agriculture
Establish demonstration projects
Support with subsidies and foreign aid
Establish training programs
Sustainable Organic Agriculture
Solutions
Sustainable Organic Agriculture
More Less
High-yield polyculture Soil erosion
Organic fertilizers Soil salinization
Biological pest control Aquifer depletion
Integrated pest Overgrazing
management
Overfishing
Irrigation efficiency
Loss of
Perennial crops biodiversity
Crop rotation Loss of prime
cropland
Use of more water-
efficient crops Food waste
Soil conservation Subsidies for unsustainable
farming and fishing
Subsidies for more
sustainable farming and Population growth
fishing
Poverty
Fig. 10-31, p. 234
What Can We Do?
What Can You Do?
Sustainable Agriculture
•Waste less food
•Reduce or eliminate meat consumption
•Feed pets balanced grain foods instead of meat
•Use organic farming to grow some of your food
•Buy organic food
•Compost your food wastes
Fig. 10-32, p. 234
