Chapter 13: Food Resources
I.
How is food produced?
Historically speaking, humans have depended on the following three systems for their
food supply:
a. croplands
b. rangelands
c. ocean fisheries
Some notable facts: there are 30,000 plants with parts that human can eat but only 15
plant and 8 terrestrial animal species supply 90% of our diet. In other words, we are very
limited in our diet currently. (We are picky eaters!!)
Wheat, rice, and corn provide more than half the calorie that people consume. 2/3 of the
world’s population survive primarily on traditional grains such as rice, wheat, and corn
because they cannot afford meat. Fish and shellfish are an important source of food for
about 1 billion people mostly in Asia and in coastal areas of developing nations.
Wheat
Points of connection: All crop production involves replacing species-rich late
successional communities such as mature grasslands and forests with an early
successional community consisting of a single crop (monoculture) or a mixture of crops
(polyculture) invasion of nonnative species often through human intervention.
Two Major Types of agricultural systems:
A. Industrialized

Industrialized agriculture (high-input agriculture)practiced on 25% of all
cropland mostly in developing nations.

Plantation agriculture (low-input agriculture)practiced primarily in tropical
developing countries; involved growing cash crops on large monoculture
plantations for sale in developed countries (Ex: Dole banana plantation in
Guatamala)
B. Traditional
-practiced by 2.7 billion people (44% of the world’s population) in developing
nations and provide about 20% of the world’s supply.
 Traditional subsistence agricultureuses mostly human labor and draft
animals (water buffalo) to produce only enough crops or livestock for a
farm family’s survival.
 Traditional intensive agriculturefarmers increase their inputs of human
and animal labor, fertilizer, and water to get a higher yield per area of
cultivated land to produce enough food to feed their families and to sell
for additional income.
II.
Producing Food by Green Revolution and Traditional Techniques
What is the “Green Revolution”?
1st Green Revolution1950-1970
a) developing and planting monocultures of selectively bred or genetically
engineered high-yield varieties of key crops such as rice, wheat, and corn.
b) Using large inputs of fertilizers, pesticides, and water on crops to produce high
yields
c) Increasing the intensity and frequency of cropping
2nd Green Revolutionsince 1970
uses 8% of the world’s petroleum inputWHY? (Important)
a) increased yields of rice and wheat from varieties specially bred for tropical and
subtropical climates.
Food For Thought: In the US, about 10 units of nonrenewable fossil fuel energy
are needed to put 1 unit of food energy on the table. How many units of
nonrenewable food energy would be needed to put a McDonald’s Big Mac Meal
on the table. (Big Mac Burger, 1 Medium Coke, and 1 Medium
Fries)Important
Low-Input Agrodiversity in Action: Interplanting
Types of Interplanting:
1) polyvarietal cultivation (planting many different varieties of rice for example)
2) intercropping (many different cropsallowing soil to not be depleted of the same
nutrients every year)
3) agroforestry or alley cropping
Food for Thought: Why is interplanting more environmentally sustainable?
Importance of Soil Erosion and Degradation to Agricultural Production

Soil erosionthe movement of soil components, especially surface litter,
topsoil, from one place to another by the action of wind and or water.
a. Sheet erosion occurs when surface water or wind peel off fairly
thin sheets or layers of soil.
b. Rill erosion occurs when fast-flowing little rivulets of surface
water make small channels in the soil.
c. Gully erosion occurs when rivulets of fast flowing water join
together to cut wider and deeper ditches or gullies.
 Soil erosionloss of soil fertility; water pollution
 Soil erosionDesertification (Ex: Sahara Desert is
advancing year by year down the continent of
Africa) WHY?
III.
Food Production, Nutrition, and Environmental Effects
Good News:
a) world grain production has tripled
b) average food prices adjusted for inflation has dropped by 25%
c) the amount of food traded (exported/imported) in the world has quadrupled
d) global meat production mostly beef, pork, and poultry has risen for 41
consecutive years.
Bad News:  Distribution of Food is the Problem
a) population growth is outstripping food production
b) global grain production has leveled off
c) rangelands and ocean fisheries are approaching their limits
d) if everyone ate the typical diet of a person in a developed country, with 30%-40%
of the calories coming from animal products, the world’s current agricultural
system could only support an estimated 2.5 billion people (current world
population is 6.2 billion people)
Food For Thought: 1/6 in developing nations do not get enough to eat. 1/7 in
developed countries eat too much.
 Underfed and underweight individuals/overfed and overweight individuals
face similar problems: lower life expectancy, increased susceptibility to
diseases and illness, and reduced productivity and life quality.
To maintain good health:
a) macronutrients (proteins, carbohydrates, and fats)
b) micronutrients (vitamins A, C, and E and minerals such as iron, iodine, and
calcium)
Undernutrition-when people cannot grow or buy enough food to meet their basic energy
needs.
Malnutrition-when people are forced to live on a low-protein, high-carbohydrate diet
consisting of only grains such as wheat, rice, or corn.
Diseases due to nutritional deficiencies:
 marasmus-low in both calories and protein
 kwashiorkor-low in protein
 vitamin A-results in blindness
 anemia-lack of iron
 goiter-lack of elemental iodine
Obesity-caused by too much food and or too little exercise; second cause of death after
smoking. More than ½ of all adult Americans are overweight and 20% are obese.
Food For Thought:
 we produce more than enough food to meet the basic nutritional needs of
every person on the earth today.
 If distributed equally, the grain currently produced worldwide is enough to
give everyone a meatless subsistence diet.
 The bad news is that food is not distributed equally because of the
following reasons:
 Differences in soil
 Differences in climate
 Differences in political and economic power
 Differences in average per capita income (buying power)
 Principal cause of hunger and malnutrition is and will continue to be
POVERTY.
Additional Food for Thought: What are the environmental costs of food production?
What is your carbon foot print based on your daily diet alone?
IV.
Increasing World Crop Production
a) Use of cross-breeding techniques
b) Genetic Modified Organisms (GMO)
c) Trying New Foods
o Winged bean-protein rich legume found only in Southeast Asia and New
Guinea
o Insects (microlivestock)
 Black ant larvae (Mexican tacos)
 Giant Waterbugs (Thai Vegetable Dip)
 Emperor Moth Catepillars (Africa)
 Cockroaches (Kalahari Desert, Africa)
 Lightly toasted butterflies (Bali)
 French-fried Ants (Bogota, Columbia)
d) Irrigating More land
What is the problem with too much irrigation?

Salinizationoccurs when repeated applications of irrigation water in
dry climates lead to the gradual accumulation of salts in the upper soil
layers through the process of evaporation and transpiration. kill
plants, ruins the land (becomes too salty)

Waterloggingdownward percolation of precipitation and irrigation
water raises water table kill plants
e) Cultivating More land through Soil Conservation
 Conservation-tillage farmingdisturb the soil as little as possible

Terracing

Contour farming

Strip Cropping

Windbreaks or shelterbelts
f) Restoring Soil Fertility
 Organic Fertilizers (animal manure; green manure; compost; human waste
(night soil)

Commercial Inorganic Fertilizer (N-P-K)
g)Growing Food in Urban Areas
-idea of an urban garden/rooftop garden
h) Crop Rotation
V.
Producing More Meat
Rangeland-unfenced land that is for grazing animals such as cattle, sheep, etc.
Pasture-managed grasslands or enclosed meadows usually planted with domesticated
grasses or other forage
Ecology of Rangeland Plants:
 Deep and complex root systems
 Grow from the base not from the top; upper half (metabolic reserve)
 Grass help anchor plants
 Grass extract underground water so plants can withstand drought
 Grass store nutrients so that plants can grow after a drought or fire
Food For Thought: How is meat produced and what are its environmental consequences?
(Free Range cattle vs. Pen Cattle)
Overgrazing-when too many animals graze for too long and exceeded the carrying
capacity of a grassland area.
Undergrazing-when the absence of grazers for a long period of time (at least 5 years)
which can reduce the net primary productivity of grassland vegetation and grass cover.
Rangeland management-controlling the number, types, and distribution of livestock
grazing on land, deferred grazing, and rangeland restoration and improvement.
VI. Catching and Raising More Fish
Commercial Fishing is divided into 6 major groups of fish and invertebrates:
 Herring, anchovies, and sardines (pelagic species)

Salmon

Cod family (demersal)

Mackerels and tunas

Flatfish (flounders, sole, halibut)

Invertebrate mollusks and crustaceans (shrimps, lobsters, crabs, oysters, clams,
octopuses, and squid)
What are the environmental problems associated with commercial fishing? (Chapter 12
notes on fishing methods)
Overfishingtaking of so many fish that too little breeding stock is left to maintain
numbers viable for reproduction; that is overfishing is a harvest that exceeds a species’s
sustainable yield. Prolong overfishing will lead to commercial extinction.  reread Mark
Kurlansky’s Cod
What is aquaculture? (25% of the world’s commercial fish harvest)
Fish farmingcultivating fish in a controlled environment, often a pond or tank,
and harvesting them when they reached the desired size.
Fish ranchingholding fish in pens for the first few years of their lives, releasing
them, and harvesting the adults when they return to spawn (Ex: ranching of Coho
salmon in Santa Cruz)
Food for Thought: What are the pros and cons of aquaculture?
VII. Agricultural Policy and Food Aid
How can government agricultural policies affect food production?
 Keep food prices artificially low
 Give farmers subsidies ($$) to keep them in business and encourage them
to increase food production
 Eliminate most or all price controls and subsidies
 Food aid (USAID)
Food For Thought: How can sending food aid be harmful?
VIII. Solutions: Sustainable Agriculture
Components:
Increase:
o High yield polyculture
o Organic fertilizers
o Biological pest control (Ex: use of insects to control other insectstaking
advantage of natural predator-prey interactions [natural enemies])
-Pesticides (insecticides, herbicides, fungicides, and rodenticides)
 1st Generationchemicals from plants (copying nature)
 2nd Generationman-made chemicals (DDT)work fast; save human
lives; increase food supplies; increase profits for farmers; when use
properly, minimal health risks to humans; newer pesticides are more safer
and effective than many older ones.
 Broad spectrum
 Narrow spectrum
 Persistence (how long do they last in the environment)
 What is the ideal pesticide?
 Kill only the target pest
 Not cause genetic resistance in target organism
 Disappear or break down into harmless chemicals after doing
its job
 Be more cost effective than doing nothing
 What is the problem with 2nd generation pesticides?
 Accelerate the development of genetic resistance to pesticides by
pest organismsgenetic treadmill

They put farmers on a financial threadmill

Some insecticides kill natural predators and parasites that help
control the pest populations.
Pesticides do not stay put and can pollute the environment.
Some pesticides harm wildlife.
Some pesticides can threaten human health.



 Pesticide Laws
 FIFRA (Federal Insecticide, Fungicide, and Rodenticide Act)
[1947, amended in 1972)
o Integrated Pest management (use of biological, chemical, and ecological methods
to manage pests)
 Fool the pest.
 Provide homes for pest enemies.
 Implant genetic resistance.
 Bring in natural enemies.
 Use insect perfumes (pheromones)
 Bring in the hormone
 Spray with hot water
o Irrigation efficiency
o Crop rotation
o Use of more water efficient crops
o Soil conservation
o Subsidies for more sustainable farming and fishing
Decrease:
o Soil erosion
o Soil salinization
o Aquifer depletion
o Overgrazing
o Overfishing
o Loss of biodiversity
o Loss of prime cropland
o Food waste
o Subsidies for unsustainable farming and fishing
o Population growth
o Poverty
What makes something 100 % organic?
o No pesticides, synthetic fertilizers, antibiotics, growth hormones, genetic
modification.
o Animals must be raised on organic feed, given no steroid growth hormones, given
antibiotic to treat diseases, and given access to the outdoors (free range)