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Chapter 10: Agriculture
The Cultural Landscape:
An Introduction to Human Geography
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Where Did Agriculture Originate?
• LDCs are home to 97% of world’s farmers
– Recall: Agriculture is a primary-sector economic
activity
• Origins of agriculture
– Agriculture = deliberate modification of Earth’s
surface through the cultivation of plants and/or
rearing of animals to obtain sustenance.
• Cultivate = “to care for”
• Crop = any plant cultivated by people
– Agriculture originated when humans domesticated
plants & animals for their use.
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Where Did Agriculture Originate?
• Hunter & Gatherers
– Before agriculture, H & G lived in small groups of about 50 ppl.
Men would hunt or fish & women would collect berries, nuts, etc.
– Groups would travel frequently. Direction and frequency of travel
would depend on mov’t of game & seasonal growth of plants.
– Perhaps 250,000 remaining today (0.005% of world’s population).
• Invention of agriculture
– When it began = unclear; Generated from many hearths
– SW Asia thought to be hearth for domestication of largest # of
animals important for agriculture (cattle, goats, pigs, sheep).
– Scientists do not agree on whether agriculture originated primarily
b/c of environmental or cultural factors.
• Environmental—Domestication of crops & animals coincides w/ climate
change around 10,000 years ago (end of Ice Age)
• Cultural—Human behavior responsible for wanting to live in a fixed place.
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Crop Hearths—Agriculture originated in many hearths.
Domestication of some crops can be dated back more than
10,000 years.
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Animal Hearths—Animal domestication also originated
in many hearths.
Figure 10-3
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Where Did Agriculture Originate?
• Commercial and Subsistence agriculture
– Subsistence = produced mainly for the farm family’s survival
• Most common in LDCs
– Commercial = produced mainly for sale off the farm
• Most common in MDCs
– Most widely used map of agricultural regions created by
Derwent Whittlesey in 1936.
• He identified 11 major agricultural regions, plus an area where
agriculture is nonexistent. Divided 11 regions to 5 that are important
to MDCs & 6 important to LDCs.
– Similarities between agriculture & climate maps are striking
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In the Middle East & N. Africa, which has a dry climate, pastoral
nomadism is the predominant type of agriculture. SE China has warm
mid-latitude climate with wet rice dominant whereas NE China has cold
mid-latitude climate with intensive subsistence agriculture w/ wet rice
not dominant.
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Major agricultural practices can
be divided into subsistence &
commercial regions.
Subsistence regions—LDCs
Shifting cultivation—primarily
tropical regions of S. America,
Africa, & SE Asia
Pastoral nomadism—primarily
dry lands of North Africa and
Asia.
Intensive subsistence, wet rice
dominant—large population
concentrations of E. & S. Asia
Intensive subsistence, crops
other than rice dominant—
population concentrations of E.
and S. Asia where growing rice
is difficult.
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Commercial regions include:
(All MDCs except Plantation)
Mixed crop & livestock—
primarily US Midwest and
Central Europe.
Dairying—near population
clusters in NE US, SE
Canada, and NW Europe
Grain—North-Central US and
Eastern Europe
Ranching—Drylands of W US,
SE S. America, Australia
Mediterranean—Lands
surrounding Mediterranean
Sea, W. US, & Chile
Commercial gardening—SE
US & SE Australia
Plantation (LDCs)—Tropical
regions of Latin America,
Africa, & Asia.
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5 Features that Distinguish Commercial from Subsistence
• Purpose of Farming
– LDCs (subsistence)—Produce food for own consumption
– MDCs (commercial)—Produce food for sale rather than consumption
• % of Farmers in Labor Force
– LDCs—50% of workers engaged directly in agriculture
– MDCs—5% engaged in agriculture
• Use of Machinery
– MDCs—A small # of farmers can feed many ppl by relying on machinery
– LDCs—Many farmers do work w/ hand tools & animal power
• Farm Size
– MDCs—Commercial agriculture dominated by handful of large farms
• Relationship of Farming to Other Businesses
– MDCs—Agribusiness, the family farm is integrated into a large foodproduction industry. Although farmers are less than 2% of workforce, 20% of
US labor works in food production related to agribusiness.
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In LDCs most people work in agriculture to produce the food they and
their families require. In MDCs few people are farmers, and most people
buy food w/ money earned by working in factories or offices.
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Farmers in MDCs have
more tractors per
hectare, or acre of land
than do farmers in
LDCs. The machinery
makes it possible to
farm extensive areas, a
practice necessary to
pay for the expensive
machinery.
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Where are Agricultural Regions in LDCs?
• This section considers the 4 agricultural types characteristic of
LDCs—Shifting cultivation, pastoral nomadism, intensive
subsistence, & plantation.
• Shifting Cultivation
– Most prevalent in low-latitude, A-type climates (high
temperatures & abundant rainfall)
• S. America, Central and West Africa, Southeast Asia
– Two features:
• Land is cleared by slashing and burning debris (slash-and-burn
agriculture)
• Land is tended for only a few years at a time until soil is depleted
– People who practice this generally live in small villages and
grow food on the surrounding land.
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Shifting Cultivation (LDCs)
• The Process of Shifting Cultivation
– Villagers designate planting area each year. Before planting,
they remove dense vegetation that covers tropical land.
– On a windless day, the debris (trees mostly) is burned
– The cleared land, known by some as swidden, is prepared
by hand w/ help of a hoe (plows and animals are rarely
used).
– Cleared land can support crops for no more than 3 years
normally. Rapid weed growth attributes to this abandonment
after a few years.
– Villagers may return to the site 6-20 years later to begin the
process of clearing the land again.
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Slashing and burning vegetation. The dense vegetation is
chopped down, and the debris is burned in order to provide the
soil w/ needed nutrients.
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Shifting Cultivation (LDCs)
• Crops of Shifting Cultivation
– Since most families grow for their own needs, their farm appears much
more chaotic than do fields in MDCs, where a single crop such as corn
or wheat may grow over an extensive area.
• Ownership & Use of Land in Shifting Cultivation
– Traditionally, land was owned by village, not each resident.
– Today, private individuals own land, especially in Latin America.
– Shifting cultivation occupies ¼ of world’s land area, a higher % than any
other type of agriculture.
– However, less than 5% of world’s people engage in shifting cultivation.
The practice of moving from one field to another every couple of years
requires more land per person than do other types of agriculture.
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Shifting Cultivation (LDCs)
• Future of Shifting Cultivation
– Amount of Earth’s surface allocated to tropical rain forests has already
been reduced to less than half of its original area.
– Compared to other forms of agriculture, shifting cultivation can support
only a small population in an area w/o causing environmental damage.
– Defenders of shifting cultivation consider it the most environmentally
sound approach for the tropics. Practices used in other forms of
agriculture, such as fertilizers and pesticides may damage the soil, cause
severe erosion, and upset balanced ecosystems.
– However, large-scale destruction of rain forests may contribute to global
warming. When large numbers of trees are cut, their burning and decay
releases carbon dioxide that will build up in the atmosphere.
– With the widespread recognition of global warming, LDCs have become
pressured to restrict further destruction of rain forests. Bolivia agreed to
set aside 3.7 million acres in a forest reserve in exchange for
cancellation of $650,000,000 of its debt to developed countries.
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Deforestation of Amazon tropical rainforest has increased from 7 million acres
per year during 1990s to 8 million acres since 2000. Cash crops such as
soybeans are replacing forests in Brazil.
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Pastoral Nomadism (LDCs)
• Pastoral nomadism (herding domesticated animals)
– Found primarily in arid and semiarid climates: Southwest Asia, North Africa
– They are sedentary farmers who cultivate grain in one place
– Only about 15 million people are pastoral nomads. They sparsely occupy
about 20% of Earth’s land area.
• Characteristics of pastoral nomadism
– Animals are seldom eaten—They consume grain
• Size of herd indicates power & they serve as main security in adverse
environmental conditions.
– Type of animal depends on the region
• Camels favored in North Africa and Southwest Asia. Horses in Central Asia
– Movements of Pastoral Nomads
• Strong sense of territoriality—goal for each group is to control a large enough
area to contain forage (food for animals) and water necessary.
• Transhumance practiced—seasonal migration of livestock between
mountains and lowland pasture areas.
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The Future of Pastoral Nomadism
• Used to be seen as a practical way of surviving on
land that receives too little rain for cultivation of crops.
• Today, it’s a declining form of agriculture
– Victim of modern technology—B4 transportation and
communications inventions, pastoral nomads played
important role as carriers of goods and information across
the sparsely inhabited dry lands.
– Governments force groups to give up pastoral nomadism b/c
they want the land for other uses. In some cases, mining
and petroleum industries now operate in dry lands formerly
occupied by pastoral nomads.
– In the future, pastoral nomadism will be confined to areas
that cannot be irrigated or that lack valuable raw materials.
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Intensive Subsistence Agriculture (LDCs)
• Found in areas with high population and agricultural densities
– Term intensive implies farmers must work intensively to subsist on
a parcel of land. Found mainly in East, South, and Southeast Asia
– To maximize production, little to no land is wasted. Example:
Roads are made narrow to minimize loss of land.
• Intensive with wet rice dominant
– Term wet rice refers to practice of planting rice on dry land and
then moving the seedlings to a flooded field to promote growth.
– Wet rice occupies small % of land but is region’s most important
source of food.
– Successful production of large yields is time-consuming & done
mostly by hand. All family members, including children, contribute
to the work.
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Intensive Subsistence Agriculture (LDCs)
• Steps for Growing Rice
– Farmer prepares field for planting, using a plow drawn by water buffalo
or oxen—use of plow & animal plow is one characteristic that
distinguishes subsistence from shifting cultivation.
– Plowed land is then flooded w/ water, which is collected from rainfall or
irrigation. Too much or too little water can damage the crop.
• Before planting, dikes and canals are repaired to ensure the right quantity of
water in the field. The flooded field is called a sawah, not a paddy
– Rice plants grow submerged in water for ¾ of growing period
• Since plants are submerged most of the time, wet rice most
easily grown on flat lands.
– Thus, most cultivation takes place in river valleys and deltas.
– Land is used even more intensively in parts of Asia that practice double
cropping, obtaining two harvests per year from one field. This involves
alternating between wet rice, grown in summer when there’s high
precipitation & dry crops (wheat) during the drier winter season.
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Labor intensive wet rice—Needs to be grown on flat land, so hillsides are
terraced to increase the area of production.
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Rice is most important crop in the large population
concentrations of East, South, and Southeast Asia.
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Intensive Subsistence Agriculture (LDCs)
• Intensive Subsistence w/ Wet Rice NOT Dominant
– Climate with low precipitation levels in summer or harsh
winters are not suitable for growing rice. Agriculture in
interior India & NE China is devoted to crops other than rice.
– Crops include: oats, corn, cotton, tobacco, & soybeans
– In milder regions where wet rice is not dominant, more than
one harvest can be obtained some years through skilled use
of crop rotation, which is the practice of rotating use of
different fields from crop to crop each year to avoid
exhausting the soil.
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Plantation Farming (LDCs)
• Plantation farming
– Form of commercial agriculture found in tropics and
subtropics: Latin America, Africa, and Asia
– Typically owned & operated by Europeans or N. Americans.
• Products are grown in LDCs but typically are sold to MDCs
– Plantation—a large farm that specializes in 1 or 2 cash crops
• Important crops = coffee, sugarcane, cotton, rubber, and tobacco
– Because plantations are usually situated in sparsely settled
locations, they must import workers & provide them w/ food,
housing, and social service.
– After the Civil War, plantations declined in the US; they were
subdivided and either sold to individual farmers or worked by
tenant farmers.
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Plantation worker
Workers are harvesting
palm fruit here in
Indonesia, which will be
processed into palm oil.
Indonesia is world’s
largest palm oil producer.
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Where are Agricultural Regions in MDCs?
• This section will discuss the six main types of commercial
agriculture in MDCs.
Mixed Crop and Livestock Farming (MDCs)
– Common in US west of Appalachians and in much of Europe
– Most distinctive characteristic is its integration of crops &
livestock. Crops are fed to animals rather than humans so that the
livestock manure will improve soil fertility to grow more crops.
– Devotes nearly all land to growing crops but derives more than ¾
of income from sale of animal products (beef, milk, eggs).
– In US, corn (maize) is most frequently planted in mixed crop &
livestock farms b/c it generates higher yields per area than other
crops.
– Most important region in US, extending from Ohio to the Dakotas
with center in Iowa, is called the Corn Belt (half cropland is corn in
this area)
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Mixed crop and livestock farm that grows corn in Iowa
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Corn (maize production)—US accounts for more than 40% and
China nearly 20% of world’s corn production. Outside North
America, corn is called maize.
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Dairy Farming (MDCs)
• Most important commercial agriculture practiced on farms near
urban areas of NE US, SE Canada, and NW Europe.
• Regional Distribution of Dairying
–
–
–
–
For most of 20th century, world’s milk production was mostly in MDCs
Share of production increased from 26% in 1980 to 51% in 2007 in LDCs
In 21st century, India has surpassed US as leading milk producer
Dairy products must be closer to their market b/c their products are
highly perishable. The ring surrounding a city from which milk can be
supplied w/o spoiling is known as the milkshed.
– Like most commercial farmers, dairy farmers generally sell their milk to
wholesalers, who distribute the products to retailers.
• Challenges to Dairy Farmers
– Labor intensive—Cows must be milked twice a day, thus requiring
constant attention throughout the year.
– Winter feed—Must feed cows when they’re unable to graze on grass.
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MDCs have ¼ or world’s population but produce more than ½ of
world’s milk. However, production has expanded rapidly in LDCs
in recent years.
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Dairy farmer in Vermont—Dairying is a major type of agriculture in NE US, a
region that is w/in the milksheds of several major metropolitan areas.
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• Can you think of a few factors that would contribute to the
steady decline in the number of dairy farms since 1970?
• Can you think of a few factors that would contribute to the
increase in the number of organic farms since 1970?
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Dairy/Organic Farms
• Factors that would contribute to the steady decline in
the number of dairy farms:
– Increased production of milk
• Cows produce higher yields, meaning fewer cows are needed to
meet the demand for milk
– Increased mechanization
• Mechanization/technological changes in the milking process have
enabled farmers to increase the size of their dairy herbs. This
efficiency has made small farms unprofitable.
– Displacement by urbanization
• Dairy farmers close to cities where dairy farms traditionally have been
located (milk shed) have been displaced by urbanization, leading to a
decline in the number of dairy farms overall.
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Dairy/Organic Farms
• Factors that would contribute to the increase in the
number of organic farms:
– Increasing demand for organic products has made it more
profitable and led to a growth in organic farming
• Consumers in US seek alternatives to modern agriculture b/c of
concerns about the nutrition and healthiness of commercial products.
• People in US are better able to afford higher prices for organic stuff.
• Better advertising have made organic products more appealing
– Small farms competing with large-scale farms (agribusiness)
are forced to shift to more profitable agriculture
• Small-farm operations cannot compete with the economies of scale
achieved by large-farm operations. Small farms must either go out of
business or shift to more intensive forms of agriculture or supply
specialty food for niche markets that bring higher prices and greater
profitability.
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Economies of scale are achieved by large industries that increase
output so much that the average cost to the industry is greatly
decreased.
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Grain Farming (MDCs)
• Grain is the seed from various grasses, like wheat, corn, etc.
• Commercial grain agriculture is different from mixed crop and
livestock farming b/c crops are grown primarily for consumption
by humans rather than livestock.
• Most important grain crop = wheat
– US & Canada account for about half the world’s wheat exports. N.
American prairies are labeled the world’s “breadbasket.” The ability to
provide food for many people across the world is a major source of
economic and political strength for US and Canada.
– Large-scale grain production is concentrated in 3 areas: winter-wheat
belt (Kansas, Colorado, Oklahoma) where crop is planted in autumn and
develops a strong root system that will survive the winter, spring-wheat
belt (Dakotas, Montana, south Canada) where winters are too severe,
and the Palouse region of Washington State.
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China and India have passed the US as leading producer of
wheat. However, the US remains the leading producer of wheat
for commercial sale off the farm.
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Livestock Ranching
• Ranching is the commercial grazing of livestock over an
extensive area.
– Practiced in MDCs where vegetation is too sparse to support crops.
– Cattle ranching expanded in US during 1860s b/c of the demand for beef
in East Coast cities.
– Cattle ranching declined in importance in 1880s after the US gov’t sold
land that used to be open for grazing to farmers.
– Ranchers tried to drive out farmers by cutting fences and then illegally
erecting their own fences on public land. “Range wars” flared. The
farmers most potent weapon was barbed wire, first produced in 1873.
– Farmers eventually won the battle, and ranchers were compelled to buy
or lease land to accommodate their cattle.
– Ranching generates lower income per area of land, although it has lower
operating costs. Cattle are still raised on ranches but are frequently sent
to fattening farms rather than directly to meat processors.
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Cattle, sheep, and goats are the three animals most commonly
found on ranches. Cattle are found in Western Hemisphere,
sheep in Australia, and goats in Central Asia.
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Poultry (Chicken & Turkey)
• The restructuring of agriculture in late 20th century has had
important implications for rural land use and distribution of
poultry in the United States.
• There have been many factors that have increased the demand
for poultry in the late 20th century:
–
–
–
–
–
–
Population increase
Health benefits (low fat diets)
Enhanced image of poultry (ease of preparation, appearance)
Availability (growth of poultry-based franchises like Chick Fil-A)
Some groups have ethnic/religious taboos against beef and pork
Falling prices of poultry compared to other meats
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Poultry (Chicken & Turkey)
• Characteristics of the present economic organization of poultry
production in the US:
– Corporation controls multiple elements of poultry production (feed
production-delivery of feed, vertical integration)
– Large scale operations (as seen in the number of birds per farm)
– Specialized farms (they raise poultry only)
– Application of manufacturing process (mass production style/factory like)
• Features of present geographic distribution of poultry
production in the United States
– Regional concentration or clustered in a particular location
– Proximity to markets or transportation corridors
– Regional concentration in economical depressed areas or areas w/ low
wages (attraction of an immigrant work force).
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Mediterranean Agriculture (MDCs)
• Every Mediterranean area borders a sea and most are on west
coasts of continents.
– Sea winds provide moisture and moderate winter temperatures
– Land is very hilly, mountains frequently plunge directly to the sea, leaving
very narrow strips of flat land along the coast.
– Most crops are grown for human consumption, not for animal feed
– Horticulture—the growing of fruits, vegetables, and flowers—and tree
crops form the commercial base of Mediterranean farming.
• Crops in Mediterranean Region
– In lands bordering these regions, olives & grapes are most important
cash crops. 2/3 of world’s wine is produced in countries that border the
Mediterranean, especially Italy, France, and Spain.
– Approximately half the land is devoted to growing cereals, especially
wheat for pasta and bread.
– Large portion of California is devoted to fruit and vegetable horticulture.
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Commercial Gardening & Fruit Farming
• Predominant type of agriculture in US southeast
– Region has long growing season, humid climate, and is accessible to
large markets of NYC, Washington, & Philadelphia.
• Type of agriculture practiced is called truck farming.
– Truck farms grow many of fruits and vegetables that consumers in more
developed societies demand (i.e. apples, asparagus, cherries, lettuce,
tomatoes).
– Truck farms are highly efficient large-scale operations that take full
advantage of machines at every stage of the growing process.
– Labor costs are kept down by hiring migrant farm workers, some of
which are undocumented from Mexico & will work for low wages.
– Farms tend to specialize in a few crops, and a handful of farms may
dominate national output of some fruits and vegetables.
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Why Do Farmers Face Economic Difficulties?
• Challenges for commercial farmers
– The distance from the farm to the market influences the
farmer’s choice of crop to plant.
• The von Thünen model (1826)
– A commercial farmer initially considers which crops to cultivate
and which animals to raise based on market location.
– In choosing an enterprise, the farmer compares two costs: Cost of the
land & the cost of transporting products to market.
– He based his general model on spatial arrangement of different crops in
his experiences as owner of a large estate in northern Germany.
– Model assumed that all land in a study area had similar site
characteristics although he recognized that the model could vary
according to physical conditions.
– Model failed to consider that social customs and gov’t policies influence
the attractiveness of plants & animals for a commercial farmer.
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Von Thunen model of the role of situation factors in choice of crops—Different
types of framing are conducted at different distances from a city. Von Thunen
recognized that his model would be modified by site factors, such as a river
(right), which changes the accessibility of different land parcels to the market
center. Agricultural uses that seek highly accessible locations would need to
locate nearer to the river.
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Applying Von Thunen’s Model
• You are given two different types of farms: A fresh produce
farm and a large scale grain farm
• Predict the locations of the two farms relative to an urban area
– Fresh Produce—closer to or in the city
– Grain—farther from the city
• For each of the two, explain the location:
– Fresh Produce—intensive agriculture, higher-value land, perishable
goods, accessibility to market, where farmer can maximize profit
– Grain—extensive agriculture, lower-value land, less accessibility to the
market, where farmer can maximize profit
• Why do agricultural land-use patterns today differ from Thunen
– Refrigeration and food preservation, Improved transportation,
Government policy, Forests no longer occupy a zone close to market
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Why Do Farmers Face Economic Difficulties?
• Overproduction in Commercial Farming
– Agricultural efficiencies have resulted in overproduction
– Demand has remained relatively constant
• As a consequence, incomes for farmers are low b/c prices have
dropped
– US government has three policies to address this problem:
• Farmers are encouraged to avoid producing crops that are excess in supply
• Gov’t pays farmers when certain commodity prices are low
• Gov’t buys surplus production & sells or donates it to foreign governments.
– US averages $16 billion a year in farm subsidies. European
farmers receive even more. Critics charge that Europeans pay
needlessly high prices for food as a result of these subsidies.
• Irony of this situation—In an MDC such as the US, farmers are
encouraged to grow less food, whereas LDCs struggle to increase
food production to match the rate of growth in the population
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Why Do Farmers Face Economic Difficulties?
• Sustainable Agriculture
– An agricultural practice that preserves and enhances
environmental quality. Farmers engaged in this typically
generate lower revenues but they also have lower costs.
– Increasingly popular form is organic farming. Three principal
practices distinguish sustainable agriculture (and at its best
organic farming) from conventional agriculture:
• Sensitive land management
• Limited use of chemicals
• Better integration of crops and livestock
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Sustainable Agriculture—Pigs on this organic farm are fed a mixture of wheat,
oats, and tofu (soybeans) grown on the farm, not brought in from outside
suppliers as conventional farming typically does.
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Why Do Farmers Face Economic Difficulties?
• Sustainable Agriculture
– Sensitive Land Management
• Protects soil through ridge tillage, which is a system of planting
crops on ridge tops. Crops are planted on 4-8 inch ridges that
are formed during cultivation or after harvest.
• Ridge tillage features a minimum of soil disturbance from
harvest to the next planting. The space between rows matches
the distance between wheels of the machinery which keeps
the trafficked area separate from crop-growing area, which
improves soil properties.
• Over several years, the soil will tend to have increased organic
matter, greater water-holding capacity, and more earthworms.
The channels left by earthworms enhance drainage.
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Why Do Farmers Face Economic Difficulties?
• Sustainable Agriculture
– Limited Use of Chemicals
• In conventional agriculture, seeds are often genetically modified to
survive when herbicides and insecticides are sprayed on the fields to
kill weeds and insects. These are “Roundup-Ready” seeds.
• Aside from adverse impacts on soil and water quality, widespread
use of “Roundup-Ready” seeds is causing some weeds to become
resistant to the herbicide.
• Sustainable agriculture involves little or no use of herbicides.
• Farmers can control weeds w/o chemicals, but it requires additional
time and expense that few farmers can afford.
• Researchers have found that combining mechanical weed control w/
some chemicals yields higher returns per acre than relying solely on
one of the two methods.
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Why Do Farmers Face Economic Difficulties?
• Integrated Crop and Livestock
– Conventional Farming
• Many farmers choose to only grow crops or raise more animals than
the crops they grow can feed. They often sell crops off the farm or
purchase feed for animals from outside suppliers.
– Sustainable agriculture is sensitive to the complexities of
biological interdependencies between crops & livestock:
• Number of livestock—Prolonged concentration of livestock in a specific
location can result in permanent loss of vegetative cover, so the farmer
needs to move the animals to reduce overuse.
• Animal confinement—If animals are not confined, manure can contributed to
soil fertility. Confined livestock are a source of ground water pollutants & and
large densities requires waste management.
• Management of extreme weather conditions—Livestock can buffer the
negative impacts of low rainfall periods by grazing over crops that would
have been left as failures.
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Why Do Farmers Face Economic Difficulties?
• Challenges for Subsistence Farmers (recall: in LDCs)
– Subsistence Farming & Population growth
• In late 20th century, LDCs needed to provide enough food for a
rapidly increasing population as well as for the growing number of
urban residents who cannot grow their own food.
• Subsistence farmers need to increase the supply of food through
intensification of production achieved in two ways:
– Adopt new farming methods—Plows replace axes, more weeding, more
manure. The additional labor comes from the population growth. Thus,
farmland will yield more food per area, but with the growing population,
output per person will remain about the same.
– Land is left fallow for shorter periods—Under shifting cultivation, cleared
fields are utilized for a couple of years, then left fallow for 20 years. As
the # of people increases, fields will need to be left fallow for shorter
periods of time. Eventually, farmers will achieve very intensive use of
farmland characteristic of areas of high population density (i.e. E. Asia)
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Why Do Farmers Face Economic Difficulties?
• Challenges for Subsistence Farmers
– Subsistence Farming & International Trade
• For many LDCs, the main way to obtain agricultural supplies to
expand production is to import them from other countries; however,
they lack the money to buy this equipment.
• To generate these funds, LDCs often have to sell crops. MDCs are
willing to pay high prices for fruits and vegetables that would
otherwise be out of season or for crops such as coffee and tea that
cannot be grown in MDCs b/c of the climate.
• Governments in LDCs face a dilemma: The more land that is devoted
to growing export crops, the less that is available to grow crops for
domestic consumption. Rather than helping to increase productivity,
the funds generated through the sale of export crops may be needed
to feed the people who switched from subsistence farming to growing
export crops.
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Why Do Farmers Face Economic Difficulties?
• Challenges for Subsistence Farmers
– Drug Crops
• The export crops chosen in some LDCs, especially in Latin America
and Asia, are those that can easily be converted to drugs.
• Examples: Marijuana (estimated to be used by 140 million people
worldwide), Cocaine (15 million), and Heroin (14 million).
• Heroin derived from raw opium gum, which is produced by the opium
poppy plant. Afghanistan is source for around 80% or world’s opium.
• ½ of world’s coca leaf is grown in Columbia, and most of the
remainder in neighboring Peru and Bolivia.
• Marijuana, produced from the Cannabis sativa plant, is cultivated
widely around the world. The overwhelming majority of marijuana that
reaches the US is grown in Mexico. Cultivation of C. sativa plant is
not thought to be expanding worldwide, whereas opium poppies and
coca leaf are.
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Opium from Afghanistan, Cocaine in Colombia
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Why Do Farmers Face Economic Difficulties?
• Strategies to Increase Food Supply
– Four strategies are being employed to
increase world’s food supply:
• Expand agricultural land
• Increase productivity of land now used for
agriculture
• Identify new food sources
• Increase exports from other countries
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Why Do Farmers Face Economic Difficulties?
• Strategies to Increase the Food Supply
– Expand Agricultural Land
• Two centuries ago people believed that good agricultural land would
always be available for willing pioneers. Today, few scientists believe
that expansion of agricultural land can feed growing population.
– Ex: Africa’s farmed land increasing by 1% but population increasing 2%
• In semiarid regions, human actions are causing land to deteriorate to
a desert-like condition, called desertification.
– These lands can support only a handful of pastoral nomads, but
population growth has caused the land to be overused. Excessive crop
planting & animal grazing have exhausted the soil’s nutrients.
• Urbanization contributes to reducing agricultural land. Farms on the
periphery are being replaced by homes, roads, shops.
– In N. America, farmers outside urban areas are left idle until the
speculators who own them can sell them for a profit to developers, who
convert the land to urban uses.
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20th century—Agricultural land increased more rapidly than population
21st century—Agricultural land is expanding more slowly than population
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Desertification—Most severe problems are in northern Africa,
central Australia, and southwestern parts of Africa, Asia, N.
America, and S. America.
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Why Do Farmers Face Economic Difficulties?
• Strategies to Increase Food Supply
– Increase Productivity
• New agricultural practices have permitted farmers worldwide to
achieve much greater yields w/ same amount of land.
• The invention and rapid diffusion of more productive agricultural
techniques during 1970s and 1980s is called green revolution.
• Green revolution involves two main practices: new higher-yield seeds
and expanded use of fertilizers.
• Since the highest rate of population growth in history occurred during
the 20th century, many predicted global famine; however, the green
revolution was largely responsible for preventing such a food crisis.
• Farmers need tractors, irrigation pumps, and other machinery to
make the most effective use of new miracle seeds. In LDCs, farmers
cannot afford such equipment or the fuel required for the equipment,
so it’s much harder for LDCs to increase productivity.
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Green revolution
Miracle seeds have been
produced through laboratory
experiments at the International
Rice Research Institute. The
IRRI is testing rice varieties in
the Philippines.
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Green Revolution
• Green Revolution defined
– Increases in agricultural productivity that is characterized by changing
agricultural practices (commercialization, shift from subsistence to
commercial farming).
• The principal agricultural practices/technologies associated w/
the green revolution:
– Artificial fertilizer, irrigation, insecticides/herbicides, mechanical
machinery, crossbreeding
• Regions in different parts of the world where the green
revolution has had a significant impact on crop yields.
–
–
–
–
South Asia—India
SE Asia—Indonesia, Vietnam, Philippines
East Asia—China
Central America--Mexico
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Green Revolution
• The social, political, or cultural conditions necessary
for the success of the agricultural
practices/technologies of the green revolution:
–
–
–
–
–
Availability of credit/banks, money (int’l aid, finance)
Political stability, Receptive political environment
Middle class (independent) farmers
Market economy
Cultural acceptance of crops and practices (farmers must be
willing to part ways w/ the old fashioned methods of farming)
– Knowledge, education
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Green Revolution
• The economic or ecological factors that may limit the long-term
success of the agricultural practices/technologies of the green
revolution (these are causes, not effects):
–
–
–
–
–
–
–
–
Increased costs of artificial fertilizer, herbicides, fuel.
Decline in soil quality
Water pollution
Some groups (i.e. women) cannot obtain credit
Crushing debt load (for farmers, government, etc)
Availability of funds may diminish (for equipment, seeds, etc)
Climatic factors (erosion, desertification)
Potential loss of biodiversity will increase the costs of agricultural
practices to limit its success.
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Why Do Farmers Face Economic Difficulties?
• Strategies to Increase Food Supply
– Identifying New Food Sources
• Cultivate Oceans—Oceans cover ¾ of Earth’s surface but provide
only a small % of world food supply. World fish catch increased by 70
million tons from 1950-1990. The population of some fish species
have declined b/c of overfishing. To protect fishing areas, many
countries have claimed control of oceans w/in 200 nautical miles of
the coast, who have right to seize any foreign vessels in that area.
• Develop Higher Protein Cereals—People in MDCs obtain protein by
consuming meat, but people in LDCs rely on wheat, rice, corn, which
lack high protein. Scientists are experimenting w/ hybrid cereals that
have higher protein content.
• Improving Palatability of Rarely Consumed Foods—Encourage
consumption of foods that are avoided for social reasons. Many N.
Americans avoid consuming tofu & sprouts, both coming from
soybeans, which is one of America’s leading crops.
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World fish catch has not increased since around 1990. This is mostly
a result of overfishing in areas, especially in the North Atlantic and
Pacific Oceans.
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Why Do Farmers Face Economic Difficulties?
• Strategies to Increase Food Supply
– Increasing Trade
• Another alternative is to export more from countries that
produce surpluses (next slide)
• US remains the world’s leading exporter of grain by a wide
margin, accounting for 1/3 of the total exports of the 3 leading
grains (wheat, maize, rice).
• Thailand has replaced US as leading exporter of rice,
accounting for 1/3 of the world total.
• Japan is by far the world’s leading grain importing country (why
do you think that is???)
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Grain Imports & Exports—Most countries import more food than
they export. The US has by far the largest excess of food exports
compared to imports. European countries are also leading food
exporters, though they are also leading food importers.
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Case Study—Africa’s Food Supply Crisis
• Recall: Thomas Malthus argued in 1798 that population would
increase more rapidly than food supply.
– At a global scale, his thesis has not come true.
– 20th century—food supply increased more than population
– % of people suffering from undernourishment declined in all LDCs
combined from 37% in 1970 to 17% in 1995.
• The exception has been sub-Saharan Africa
– Over past half-century, undernourishment in this region has remained
constant at just under 1/3 of entire population.
– Sub-Saharan Africa is holding true to the Malthusian theory—they are
losing the race to keep food production ahead of population growth.
– Gov’t policies in the region have aggravated this crisis. To make food
affordable for urban residents, governments keep agricultural prices low.
Constrained by price controls that limit profitability, rural farmers have
little incentive to increase productivity.
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Progress in reducing undernourishment has been
substantial in Asia but not in other LDCs
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Population and Food Production in sub-Saharan Africa—Levels of population
and food production in 1961 were set at 100 in the chart. Since 1980s,
population has increased more rapidly than food production in this region.
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The End.
Up next: Industry
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