Master the Von Thünen Model, the Green Revolution, subsistence vs. commercial agriculture, agribusiness, and the environmental consequences of farming.
Unit 5 covers the geography of agriculture — how food is produced, where it is produced, and why it is produced where it is. It accounts for roughly 12–17% of the AP exam and requires applying both models and real-world examples.
The central model is the Von Thünen Model, which predicts agricultural land use patterns based on transportation costs. Understanding its logic — intensive, perishable products near the market; extensive uses farther out — is essential. You’ll also trace agriculture’s transformation through three revolutions: the Neolithic Revolution (settled farming), the Second Agricultural Revolution (industrialization enabler), and the Green Revolution (high-yield seeds, fertilizers, irrigation).
The unit distinguishes subsistence from commercial agriculture, and intensive from extensive agriculture — and explores how globalization is pushing regions toward commercial monoculture. Environmental impacts (soil degradation, deforestation, water pollution, desertification) and food security concepts (food deserts, food sovereignty) round out the unit.
Key terms preview
A taste of what you’ll find in The Essentials and Flashcards.
Von Thünen Model
Concentric rings of agricultural land use around a market — intensive near center, extensive at margins.
Green Revolution
High-yield seeds, fertilizers, pesticides, and irrigation that dramatically raised food production in the 20th century.
Subsistence vs. Commercial
Subsistence farming feeds the household; commercial farming produces for the market.
Agribusiness
Corporate control of multiple stages of food production from seed to supermarket.
Monoculture
Single-crop farming — efficient but ecologically vulnerable to pests and disease.
Columbian Exchange
The 1492-onward transfer of crops, animals, and diseases that transformed global agriculture.
1. The Von Thünen Model explains how transportation costs shape agricultural land use patterns
Von Thünen's model predicts that the intensity of agricultural land use and the type of crop produced depend on the cost of transporting products to the central market. Intensive, perishable products locate nearest the market; less perishable, bulkier products locate farther out. Understanding this model allows geographers to explain and predict agricultural patterns around cities.
2. Agriculture has transformed through three revolutions — and continues transforming
The Neolithic Revolution (settled farming), the Second Agricultural Revolution (industrialization enabler), and the Green Revolution (high-yield seeds and chemicals) each fundamentally changed how humans produce food. Today, precision agriculture, GMOs, and climate change are driving a fourth transformation. Understanding each revolution's causes, mechanisms, and consequences is essential for the AP exam.
3. The shift from subsistence to commercial agriculture has geographic consequences
As regions shift from subsistence to commercial agriculture, they become integrated into global commodity markets, often shifting to monoculture cash crops. This increases income but also vulnerability to price fluctuations and creates food security challenges. The Von Thünen model, agribusiness, and the Columbian Exchange all explain different dimensions of this global agricultural transformation.
4. Agricultural practices have major environmental consequences
Modern agriculture is a leading driver of deforestation, soil degradation, water pollution, greenhouse gas emissions, and biodiversity loss. Understanding the specific mechanisms — fertilizer runoff causing eutrophication, overgrazing causing desertification, monoculture increasing pest vulnerability — is essential for both exam success and geographic literacy.