XII - Food Resources Flashcards
Industrialized agriculture
Uses large amounts of fossil fuel, water, commercial fertilizers, & pesticides to produce huge quantities of single crops or livestock.
Types of traditional agriculture
Traditional subsistence
Traditional intensive
Traditional subsistence
Uses primarily human labor & draft animals to produce enough crops or livestock for a family’s survival.
Traditional intensive:
Increased inputs of labor, fertilizer, & water to achieve higher yields for sale.
Generalized Map of Food Production
Developed countries tend to use industrialized agriculture
Central SA & Africa are shifting cultivation
Northern Africa, Middle East, Northwestern China - nomadic herding
Southeastern China - Intensive traditional agriculture
Green Revolution
An agricultural system that produces more food on less land (increased yields per unit area of cropland)
Main components of Green Revolution
1) developing & planting monocultures of genetically
engineered, high–yield varieties of crops;
2) growing & protecting crops with large inputs of
fertilizer, pesticides, & water;
3) increasing the intensity & frequency of cropping
Global grain production has
Increased during the 20th century
Do we produce enough food to feed the world?
There is currently enough food produced to feed
all people, but it is unevenly distributed.
What causes the uneven distribution of food?
Many people in developing countries are undernourished or malnourished & many people in developed countries are overnourished &
waste large amounts of food.
Carry capacity of the Earth is dependent on
- the cultural carrying capacity per person;
- the sustainability of future food production;
- the percentage of the population eating meat.
Food production per capita
Slowing in early 2000s
Constant since then
What factors caused slowing?
- world population increasing;
- increasing demand for food, especially meat;
- degradation & loss of cropland;
- water supply for irrigation limited;
- declining fertilizer use.
How to increase crop yields
By increasing inputs of water, fertilizer, & pesticides
Genetic engineering
Increasing inputs of water, fertilizer, & pesticides
eventually these additions produce no additional
increase in crop yields
Genetic engineering
- raise the share of photosynthetic product in the seed;
- develop strains of plants that are resistant to disease,
insects, & drought.
New types of food comes from
• cultivation of less widely known plants; • cultivation of perennial plants reduce inputs of water, fertilizer, & energy – reduce soil erosion; • yummy insects
First green revolution
occured in developed countries
Canada
US
Most of Europe
Second green revolution
occured in developing countries Mexico China India Parts of Pacific Islands
Cultivating more land
Clearing tropical forests
Irrigate arid lands
clear tropical forests
- nutrient–poor soils will likely make agriculture unsustainable; - removal of valuable carbon sink; - loss of biodiversity.
irrigate arid lands
- expensive dams;
- depletion of groundwater
supplies.
What percent of global land is used for agriculture?
40%
world population increase will
demand greater
food production
further application of green revolution techniques
will
increase food production, but these techniques
have limitations & environmental consequences
industrialized agriculture has a
greater harmful
impact on air, soil, water, & biodiversity resources
than any other human activity
Consequences of industrialized farming includes…
Biodiversity loss Soil degradation Water pollution Air pollution Human Health
Biodiversity loss
Loss & degradation of habitat from clearing natural landscape
Fish kills from pesticide
Killing wild predators to protect livestock
Loss of genetic diversity from monoculture
Soil degradation
Erosion Loss of fertility Salinization Waterlogging Desertification
Air pollution
Greenhouse gas emission
Air pollutants from fossil fuel
Pollution from pesticide sprays
Water pollution
Aquifer depletion Increased runoff & flooding Sediment pollution from erosion Surface & groundwater pollution Over Fertilization of water sources from nitrates & phosphates runoff
Human health
Nitrates in drinking water
Pesticide residues in drinking water, food, & air
Contamination of drinking & swimming water with disease organism from waste
Bacterial contamination of meat
Env’tal impact from meat production
• more than 1/2 of the world’s cropland is used to
produce livestock feed;
• overgrazing is the major cause of desertification of arid
& semi–arid lands;
• cattle produce methane (CH
4), a greenhouse gas;
• cattle crowded into feedlots require large doses of
antibiotics.
Some methods used in sustainable agriculture increases
• reduce water waste in irrigation;
• increase use of organic fertilizers;
• emphasize biological pest control & integrated
pest management;
• increase use of soil conservation techniques.
Maximum sustainable yield
Maximum amount of fishes that can be caught without compromising env’tal health given constant conditions
How many of the major oceanic fishing areas have been fished at or beyond their estimated maximum sustainable yield for commercially valuable species & are in a state of decline?
11 of the world’s 15
Why is this happening?
- growing demand for seafood;
- efficient, large–scale industrial fishing fleets;
- degradation & destruction of coastal wetlands;
- pollution of coastal waters.
Aquaculture is also known as
blue revolution
Benefits to fish farming/ ranching
- produce high yields in a small volume of water;
* increase yields by crossbreeding & genetic engineering.
Aquaculture limitations
- conversion of coastal wetlands to fish farms;
- genetic pollution of natural fish populations by escapees;
- contamination of nearby waters with waste & chemicals
