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Food, Soil, and Pest Management
Chapter 7
Geog415
Dr Ye
What Is Food Security and Why Is It Difficult to
Attain?
 The greatest obstacles to providing enough food
for everyone are poverty, political upheaval,
corruption, war, and the harmful environmental
effects of food production.
Many People Suffer from Chronic Hunger
and Malnutrition
 Macronutrients
• Carbohydrates
• Proteins
• Fats
 Micronutrients
• Vitamins
• Minerals
Many People Do No Get Enough
Vitamins and Minerals
Most often vitamin and mineral deficiencies in people in
developing countries
 Iron
important to store oxygen in blood, lack of it will tire easily; found in oysters, meat,
poultry, and fish; vegetable has a different form not as easy to be absorbed.
 Vitamin A
Important for vision, bone growth, reproduction, etc. and also regulate immune
system by fight off infections, etc.; obtained from liver, egg, whole milk, colorful
fruits and vegetables.
 Iodine
have a major effect on thyroid function, which controls metabolism; also important for
the formation of fetal nervous system. Obtained from certain vegetables, fruits,
roots, nuts, tea, etc.
Golden rice (a genetically modified rice with a high carotene level that body
converts into vitamin A to offer the third World as cure for widespread vitamin A
deficiency.
Many People Have Health Problems from
Eating Too Much
 Overnutrition
Has 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: 77%
• Rangelands, pastures, and feedlots: 16%
• Aquaculture: 7%
All production has been increasing since 1950.
The technology advances: increased use of
tractors and farm machinery, high-tech fishing,
boats and gear; inorganic chemical fertilizers,
irrigation, pesticides, high-yield varieties of wheat,
rice, and corn; densely populated feedlots and
enclosed pens for raising cattle, pigs, and
chicken, and aquaculture ponds and ocean cages
for raising some types of fishes and shellfish
Food variety
The earth has 30,000 plant species with parts that people
can eat. However, only 14 plants and 8 terrestrial
animal species supply 90% of our global intake of
calories
Three most important corps are:
1.wheat; 2. rice; 3. corn
They provide more than half of the calories in the food
consumed by the world’s people (2/3 of people survive
primary on these)
Fish and shellfish are in important source of food for about
1 billion people, mostly in Asia and in coastal areas of
developing countries (6% protein in human diet)
Types of Food production
1.
Industrialized agriculture, high-input agriculture
Use large amounts of fossil fuel energy, water, commercial fertilizers and
pesticides to produce single crops (monocultures) or livestock animals for
sale. It is mostly in developed countries and ¼ of all cropland)
An increasing amount of livestock production in developed countries is
industrialized (feedlots fattened up for 4 month before slaughter, pigs and
chickens in developed countries in densely populated pens and cages and
eat mostly grain grown on cropland.
2. Plantation agriculture
cash crops (bananas, coffee, soybean, sugarcane, coca, and vegetables) on large
monoculture plantations (most for sale in developed countries): a form of
industrialized agriculture used primarily in tropical developing countries.
3. Traditional subsistence agriculture: use human labor and draft animals
to produce only enough crops and livestock for a farm family’s survival
4. Traditional intensive agriculture: increased input of human and draft
animal labor, fertilizer and water to get a higher yield per area of cultivated
land. They produce enough food to feed their families and to sell for income.
3 and 4 provide 42% of world’ population, mostly in developing countries and 1/5
of world’s food supply using ¾ land cultivated land
Natural Capital: Location of the World’s Principal
Types of Food Production
Green revolution
Since 1950, most of the increased in global food production has come
from increased yields per unit area of cropland in a process called
green revolution
Three steps:
1. Develop and plant monocultures of selectively bred or genetically
engineered high-yield varieties of key crops such as rice, wheat,
and corn
2. Produce high yields by using large inputs of fertilizer, pesticides,
and water
3. Increase the number of crops grown per year on a plot of land
through multiple cropping.
The first green revolution occurred during 1950-70 in developed
countries
Second green revolution occurred since 1967 in developing countries:
fast-growing dwarf varieties of rice and wheat (by Norman BourlafNobel Peace Prize winner), especially for bred for tropical and
subtropical climate.
Global Outlook: Total Worldwide Grain Production
(Wheat, Corn, and Rice)
Industrialized Agriculture uses ~17% of
All Commercial Energy Used in the U.S.
Soil Formation and Generalized
Soil Profile
Soil erosion and degradation
Land degradation occurs when natural or human induced
processes decrease the future ability of land to support
crops, livestock, or wild species.
Soil becomes more vulnerable to erosion through human
activities that destroy plant cover, including farming,
logging, construction, overgrazing by livestock, off-road
vehicle use and deliberate burning of vegetation
Effect of soil erosion:
1. Loss of soil fertility through depletion of plant nutrients
in topsoil
2. Pollute water, kill fish and shell fish, clog irrigation
ditches, boar channels, reservoirs, and lakes by eroded
soil
Natural Capital Degradation:
Global Soil Erosion
Natural Capital Degradation: Severe Salinization and
Waterlogging on Heavily Irrigated Land
Major Harmful Environmental Effects on
Food Production
Increase crop productions: Option 1. Genetic improvements
 Gene Revolution
• Cross-breeding through artificial selection
• Slow process
 Genetic engineering
• Genetic modified organisms (GMOs):
transgenic organisms
 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
A. tumefaciens
Phase 1
Gene Transfer Preparations
Plant
cell
Extract DNA
Foreign gene
if interest
Extract plasmid
plasmid
Foreign gene integrated into plasmid DNA.
Agrobacterium takes up plasmid
Phase 2
Make Transgenic Cell
A. tumefaciens
(agrobacterium)
Enzymes integrate plasmid into host cell DNA.
Foreign DNA
Host cell
Host DNA
Nucleus
Phase 3
Grow Genetically
Engineered Plant
Transgenic plant cell
Cell division of
transgenic cells
Cultured cells divide and grow
into plantlets (otherwise teleological)
Transgenic plants
with desired trait
Stepped Art
Fig. 7-3, p. 140
GMOS
Worries: know too little about the potential harm to human health and
ecosystem from the widespread use of such crops. They cannot be
recalled if they cause some unintended harmful genetic and ecological
effects. (some countries required labeling food: Japan, Europe, South
Korea, Canada, Australia, and New Zealand; US believe they are not
substantially different from foods developed by conventional crossbreeding
methods)
Bad sides:
1. Some requires huge amount of fertilizers and water and to insure its
higher yield
2. Yield may drop as soil erodes and loses fertility, irrigated soil problems
3. Crop yield may be lower than claimed because comparison was with
monoculture varieties not with polyculture cropping system
4. Increased loss of biodiversity can limit the genetic raw material needed for
future green and gene revolution; genetic uniformity increase the
vulnerability of food crops to pests, diseases and harsh weather
Trade-Offs: Genetically Modified Crops and Foods
Increase Crop Production: Option 2. Alternative foods
Introduce new types of food to markets
Examples:
1.
2.
3.
Winged bean in New Guinea and Southeast Asia,
faster growing, a good source of protein, editable in
many parts, needs little fertilizer because of nitrogenfixing nodules in its roots.
Editable insects: micro-livestock sources of protein (5878% protein by weight, 3 or 4 times as protein-rich as
beef, fish or eggs), vitamins, and minerals. 1.500
species. Black ants larvae (Taco in Mexico), giant
water bugs (vegetable dips in Thailand), emperor moth
caterpillars (South Africa), cockroaches (Kalahari
desert dwellers), lightly toasted butterflies (Bali), fried
ants (Bogota, Columbia)
Rely more on polycultures of perennial crops, better
adopted to regional soil and climate conditions than
most annual crop, eliminate the need to till soil and
replant seeds each year, thus reduce energy use, soil
erosion, water pollution.
Increase Crop production: option 3, irrigate more land
 It is limited due to poor soils, limited water, high costs, and harmful
environment effects. Clearing tropical forests and irrigating arid land
could more than double the world’s cropland. But much of this is
marginal land with poor soil fertility, steep slopes, or both and is
likely unsustainable. Potential land lies in dry areas of Australia and
Africa (expensive dam projects, fossil fuel to pump water long
distance, deplete groundwater supply, etc.). In addition the
increases in cropland would not offset the loss of almost 1/3 of
today’s cultivated cropland caused by erosion, overgrazing, water
logging, Stalinization and urbanization. It also reduce wildlife
habitats and the world’s biodiversity.
Increase food production: Option 4. Producing more
meat
Future increases in meat production come from densely
populated feedlots, where animals are fattened for
slaughter by feeding on grain grown on cropland or
meat produced from fish. Feedlots account for 43%
of world’s beef, half of pork, ¾ of poultry productions.
Expansion of feedlot production of meat will increase
the pressure on grain and fish supply (1/3 of fish is
used in feeding) and has enormous environmental
impact.
Efficiency of Converting Grain into Animal Protein
Increase efficiency:
1. Shift to more grain-efficient forms of protein
2. Shift to farmed herbivorous fish
Trade-Offs: Animal Feedlots
Increase food production: option 5. harvest more fish
and shellfish
Industrial fishing fleets using GPS equipment, sonar, nets, long fishing
lines, spotting planes, and large factory ships that can process and freeze
their catches. This accounts for 55% of commercial catch. World’s
catches start to leveled off due to overfishing, pollution, habitat loss and
population growth.
Increase food production: option 6. Aquaculture
Involves raising fish and shellfish for food like crops instead of going
out in fishing boats and hunting and gathering them
2 types:
Fish farm: cultivating fish in a controlled environment (coastal or
inland pond, lake, reservoir and rice paddy) and harvesting them
when they reach the desired size
Fish ranching: holding anadromous species, such as salmon that live
part of their lives fresh water and part in salt water, in captivity for the
first few years of their lives, usually is fenced-in-areas or floating
cages in coastal lagoons and estuaries. Then fish were released and
adults are harvested when they return to spawn.
More sustainable
aquaculture:
Open-ocean
aquaculture
Choose
herbivorous fish
Polyculture
Pests
 What is a pest?
Any species that compete with us for food, invade lawns and gardens,
destroys wood in houses, spreads diseases, invades ecosystems, or
is simply a nuisance. (100 species of plants,-weeds; animalsinsects, fungi, and microbes-infect crop plants and livestock animals,
causes about 90% of the dames to crops)
 Natural enemies—predators, parasites, disease organisms—control
pests (up to 98%)
• In natural ecosystems
• In many polyculture agroecosystems
• Pestcides or biocides: chemicals to kill or control population of
organisms we consider undesirable (insecticides, herbicides,
fungicides, rodenticides)
Modern Synthetic Pesticides Have
Several Advantages
 Save human lives
 Increases food supplies and profits for farmers
 Work quickly
 Health risks are very low relative to their benefits
 New pest control methods: safer and more
effective
Modern Synthetic Pesticides Have
Several Disadvantages (1)
 Accelerate the development of genetic
resistance to pesticides by pest organisms
 Expensive for farmers
 Some insecticides kill natural predators and
parasites that help control the pest population
 Pollution in the environment
 Some harm wildlife
 Some are human health hazards
Modern Synthetic Pesticides Have
Several Disadvantages (2)
 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
• Use alternative pest management practices
 Pesticide industry refutes these findings
Trade-Offs: Conventional Chemical
Pesticides
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
Alternatives to Using Pesticides







Fool the pest
Provide homes for pest enemies
Implant genetic resistance
Bring in natural enemies
Use insect perfumes
Bring in hormones
Scald them with hot water
7-5 How Can We Improve Food Security
and Produce Food More Sustainably?
 We can improve food security by creating
programs to reduce poverty and chronic
malnutrition, relying more on locally grown food,
and cutting food waste.
 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.
Government Policies Influence Food
Production and Food Security
Three approaches:
1. Price control: keep food prices artificially low
2. Give farmer subsidies and tax breaks to keep them in business and encourage
them to increase food production ($100 billion per year in US)
3. Eliminate most or all price controls and subsides and let farmers and fishers
respond to markert demand without government interference (government need
to increase aid for the poor and lower middle class who suffer most from food
price increase)
 United Nations Children’s Fund (UNICEF) suggests these measures
• Immunizing children against childhood diseases
• Encourage breast-feeding
• Prevent dehydration in infants and children
• Provide family planning services
• Increase education for women
Soil Conservation Methods
Restore Soil Fertility
 Organic fertilizer
• Animal manure
• Green manure
• Compost
 Commercial inorganic fertilizer active
ingredients
• Nitrogen
• Phosphorous
• Potassium
Shift to More Sustainable Agriculture
 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
What Can You Do? Sustainable
Organic Agriculture