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Introduction to
Agriculture

Explore the origins, diffusion, and evolution of farming practices that transformed human civilization and continue to shape cultural landscapes worldwide.

AP Human Geography

What is Agriculture?

Agriculture is the deliberate modification of Earth's surface through the cultivation of plants and the rearing of animals to obtain sustenance or economic gain. It is the foundation upon which all settled civilizations rest.

Why Agriculture Matters in Human Geography

Settlement
Agriculture enabled permanent settlements, replacing nomadic lifestyles with fixed communities.
Population
Reliable food surpluses fueled population growth and the rise of dense urban centers.
Culture
Farming practices shape cultural landscapes, land-use patterns, and social hierarchies worldwide.

The First Agricultural Revolution

Also called the Neolithic Revolution, this transition from hunting and gathering to settled farming began roughly 10,000 years ago. It occurred independently in multiple hearths around the world.

AGRICULTURAL HEARTHS Fertile Crescent Wheat, Barley East Asia Rice, Millet Mesoamerica Maize, Squash Sub-Saharan Africa Sorghum, Yams South Asia Cotton, Lentils Andes Potato, Quinoa

Carl Sauer and Agricultural Diffusion

Geographer Carl Sauer theorized that agriculture did not begin in areas of environmental stress. Instead, it originated in regions of biodiversity and abundance, where people had leisure to experiment with plant cultivation.

1
Vegetative planting: Reproducing plants by cutting stems and dividing roots (earliest method, originated in Southeast Asia).
2
Seed agriculture: Planting seeds from harvested crops, allowing selective breeding for desirable traits.
3
Animal domestication: Taming and breeding animals for labor, milk, meat, and hides alongside crop cultivation.

Subsistence vs. Commercial Agriculture

Subsistence Commercial
Purpose Feed the farmer's family Sell on the market for profit
Scale Small plots of land Large-scale operations
Technology Manual labor, simple tools Machinery, chemicals, GMOs
Location LDCs (developing world) MDCs (developed world)
Labor High labor input per acre Low labor, high capital input

Intensive vs. Extensive Agriculture

Intensive
High input of labor or capital per unit of land. Maximizes yield from a small area. Examples: wet rice paddies, market gardening, dairy farming.
Extensive
Low input of labor or capital relative to land area. Requires vast open spaces. Examples: ranching, shifting cultivation, nomadic herding.

The Three Agricultural Revolutions

~10,000 BCE
First (Neolithic) Revolution
Transition from hunting/gathering to settled farming; plant and animal domestication in multiple hearths.
~1700s CE
Second Agricultural Revolution
Mechanization (seed drill, crop rotation) increased efficiency; coincided with the Industrial Revolution in Europe.
~1960s CE
Third (Green) Revolution
High-yield seed varieties, chemical fertilizers, and irrigation expanded food production in developing nations.

Von Thunen's Model of Land Use

Johann Heinrich von Thunen (1826) proposed a model explaining how agricultural land use is organized around a central market. The key factor is transportation cost: perishable and heavy goods are produced closest to the city.

Wilderness (no farming) Ranching Grain Forestry Dairy & Horticulture City

Von Thunen: Key Insights

1
Perishable goods closest: Dairy and fresh vegetables surround the city because they spoil quickly and are costly to transport.
2
Forestry in ring 2: In the 1800s, wood was heavy and essential for fuel and construction, so forests stayed near the city.
3
Grain further out: Grain is lightweight, non-perishable, and easy to transport, so it can be grown far from the market.
4
Ranching on the periphery: Livestock can walk themselves to market and require vast grazing land.

Types of Subsistence Agriculture

Shifting Cultivation
Slash-and-burn clearing of forest; farm for a few years, then move. Found in tropical rainforests of Latin America, Africa, and Southeast Asia.
Pastoral Nomadism
Herding animals across large areas following seasonal grazing patterns. Common in arid regions of Central Asia, North Africa, and the Middle East.
Intensive Subsistence
High labor input on small plots; wet rice cultivation dominates in monsoon Asia. Supports dense populations with careful terracing and irrigation.

Types of Commercial Agriculture

Mixed Crop/Livestock
Crops and animals raised on the same farm; crop waste feeds livestock, manure fertilizes fields. Common in the U.S. Midwest and Western Europe.
Plantation
Large-scale, monoculture cash crops (coffee, rubber, sugarcane) in tropical LDCs, often for export to MDCs. Legacy of colonialism.
Grain Farming
Large-scale wheat, corn, or rice production for commercial markets. Highly mechanized. Found in the Great Plains, Ukraine, and Argentina's Pampas.

The Green Revolution

Beginning in the 1960s, the Green Revolution introduced high-yield variety (HYV) seeds, chemical fertilizers, pesticides, and modern irrigation to developing countries. It dramatically increased food output in places like India and Mexico.

Benefits
Prevented mass famine, increased caloric intake, reduced food prices, and enabled population growth in LDCs.
Criticisms
Environmental degradation, water depletion, increased inequality (wealthy farmers benefited most), loss of crop biodiversity.

How to Analyze Agricultural Practices

1
Identify the type: Is it subsistence or commercial? Intensive or extensive?
2
Consider the climate: What environmental conditions support the crops or livestock described?
3
Evaluate technology: What level of mechanization, irrigation, or chemical input is used?
4
Assess economic context: Is this an LDC or MDC? Is production for local use or global export?
5
Apply a model: How does Von Thunen's model or Rostow's stages of development help explain the pattern?

Common Mistakes on the AP Exam

✕ Confusing Subsistence Types
Shifting cultivation is extensive (large land, low labor per acre). Wet rice farming is intensive (small land, high labor). Don't mix them up.
✕ Ignoring Von Thunen's Assumptions
The model assumes flat terrain, no rivers, and uniform soil. Real-world deviations (highways, ports) modify the rings: always note the assumptions.
✕ Oversimplifying the Green Revolution
It was not purely beneficial. Always discuss both positive outcomes (food security) and negative consequences (environmental damage, inequality).

Question 1 of 5

The First Agricultural Revolution is also known as which of the following?

Question 2 of 5

In Von Thunen's model, which type of agriculture is located closest to the central market?

Question 3 of 5

Which of the following is the best example of extensive subsistence agriculture?

Question 4 of 5

A major criticism of the Green Revolution is that it:

Question 5 of 5

According to Carl Sauer, agriculture most likely originated in areas characterized by: