AP Human Geography_Unit 5
Agriculture, noting that if you've eaten anything, you can thank agriculture.
Elements Shaping Agriculture
Two primary elements shape agriculture: Physical Geography and Climate.
Agricultural Revolutions
The sources detail three significant agricultural revolutions that have transformed human food
production.
1. 1st Agricultural Revolution:
○ Before this revolution, small bands of people foraged for nuts and berries and
hunted animals.
○ Villages could not sustain large populations through hunting and gathering alone.
○ This revolution saw the production of the first domesticated plants
approximately 14,000 years ago in the Fertile Crescent.
○ Humans selectively chose roots or seeds from the largest, heartiest plants.
○ The emergence of a reliable food crop and surplus allowed for the rise of urban
centers.
○ Only 14 out of 148 animals meeting human criteria have been domesticated. The
five most important domesticated animals are cows, horses, sheep, pigs, and
goats.
○ This revolution is associated with the domestication and field growth that led to a
sedentary lifestyle.
2. 2nd Agricultural Revolution:
○ Occurred just before the Industrial Revolution of 1800.
○ It was necessary to feed new populations moving into factory cities.
○ Began in England.
○ Key advancements and characteristics include:
■ Crop rotation to return nutrients to the soil and prevent pests.
■ The Dutch modifying the Chinese plow to make it lighter.
■ The invention of the seed drill to make planting more efficient.
■ The internal combustion engine allowing for mechanization.
■ England's Enclosure Movement, which increased the size of single
farms to raise more sheep.
○ This revolution marks the period of industrial revolution and mechanization.
, 3. 3rd Agricultural Revolution (Green Revolution):
○ Began in the 1930s when American scientists started manipulating seeds to
increase crop yields.
○ In the 1940s, Mexico began manipulating corn varieties.
○ By the 1960s, India had cross-bred many types of rice to produce a hearty,
robust rice known as IR8.
○ In 1982, IR36 was developed to resist pests and had a shorter growing cycle,
allowing for three crops per year versus two previously.
○ The 1990s saw the US create many high-yield wheat crops.
○ Foods produced through these methods are known as Genetically Modified
Organisms (GMOs).
○ Pros of the Green Revolution:
■ Increased food supply, which was crucial when a billion people were
starving.
■ Fewer farms could feed many more people.
■ Crops are less likely to fail.
○ Cons of the Green Revolution:
■ Unknown health risks associated with gene manipulation.
■ Dependency on chemicals for production.
■ Potential for nutrient deficiencies in crops.
○ This revolution is characterized by GMOs and high-tech approaches to increase
yields. The population growth curve shows that food production has largely kept
pace with population growth, but by 2050, it is projected that food production will
again fall below world population.
Consequences and Challenges of Agriculture
Large-scale agriculture has several significant consequences and contemporary challenges:
● Desertification/Salinization:
○ Desertification is the process where fertile lands become arid and unusable for
farming, often due to over-farming.
○ Salinization occurs when soil in arid climates becomes salty due to irrigation;
water evaporates quickly, leaving behind salt residues, eventually making the
land infertile.
● Pollution: Increased application of chemicals such as petroleum-based fertilizers,
pesticides, and herbicides leads to soil, water, and air pollution, threatening ecosystems.
● Hormones are also a consequence.
● Land Cover Change: Significant alteration of natural landscapes.
● Loss of Biodiversity: Reduction in the variety of plants and animals.
● Loss of Wetlands.
● Deforestation: Rainforests cleared in large areas.
● Challenges of Contemporary Agriculture:
Agriculture, noting that if you've eaten anything, you can thank agriculture.
Elements Shaping Agriculture
Two primary elements shape agriculture: Physical Geography and Climate.
Agricultural Revolutions
The sources detail three significant agricultural revolutions that have transformed human food
production.
1. 1st Agricultural Revolution:
○ Before this revolution, small bands of people foraged for nuts and berries and
hunted animals.
○ Villages could not sustain large populations through hunting and gathering alone.
○ This revolution saw the production of the first domesticated plants
approximately 14,000 years ago in the Fertile Crescent.
○ Humans selectively chose roots or seeds from the largest, heartiest plants.
○ The emergence of a reliable food crop and surplus allowed for the rise of urban
centers.
○ Only 14 out of 148 animals meeting human criteria have been domesticated. The
five most important domesticated animals are cows, horses, sheep, pigs, and
goats.
○ This revolution is associated with the domestication and field growth that led to a
sedentary lifestyle.
2. 2nd Agricultural Revolution:
○ Occurred just before the Industrial Revolution of 1800.
○ It was necessary to feed new populations moving into factory cities.
○ Began in England.
○ Key advancements and characteristics include:
■ Crop rotation to return nutrients to the soil and prevent pests.
■ The Dutch modifying the Chinese plow to make it lighter.
■ The invention of the seed drill to make planting more efficient.
■ The internal combustion engine allowing for mechanization.
■ England's Enclosure Movement, which increased the size of single
farms to raise more sheep.
○ This revolution marks the period of industrial revolution and mechanization.
, 3. 3rd Agricultural Revolution (Green Revolution):
○ Began in the 1930s when American scientists started manipulating seeds to
increase crop yields.
○ In the 1940s, Mexico began manipulating corn varieties.
○ By the 1960s, India had cross-bred many types of rice to produce a hearty,
robust rice known as IR8.
○ In 1982, IR36 was developed to resist pests and had a shorter growing cycle,
allowing for three crops per year versus two previously.
○ The 1990s saw the US create many high-yield wheat crops.
○ Foods produced through these methods are known as Genetically Modified
Organisms (GMOs).
○ Pros of the Green Revolution:
■ Increased food supply, which was crucial when a billion people were
starving.
■ Fewer farms could feed many more people.
■ Crops are less likely to fail.
○ Cons of the Green Revolution:
■ Unknown health risks associated with gene manipulation.
■ Dependency on chemicals for production.
■ Potential for nutrient deficiencies in crops.
○ This revolution is characterized by GMOs and high-tech approaches to increase
yields. The population growth curve shows that food production has largely kept
pace with population growth, but by 2050, it is projected that food production will
again fall below world population.
Consequences and Challenges of Agriculture
Large-scale agriculture has several significant consequences and contemporary challenges:
● Desertification/Salinization:
○ Desertification is the process where fertile lands become arid and unusable for
farming, often due to over-farming.
○ Salinization occurs when soil in arid climates becomes salty due to irrigation;
water evaporates quickly, leaving behind salt residues, eventually making the
land infertile.
● Pollution: Increased application of chemicals such as petroleum-based fertilizers,
pesticides, and herbicides leads to soil, water, and air pollution, threatening ecosystems.
● Hormones are also a consequence.
● Land Cover Change: Significant alteration of natural landscapes.
● Loss of Biodiversity: Reduction in the variety of plants and animals.
● Loss of Wetlands.
● Deforestation: Rainforests cleared in large areas.
● Challenges of Contemporary Agriculture:
