The Second Agricultural Revolution

By the end of this lesson, students will be able to (per CED LO SPS-5.C):

• Define the Second Agricultural Revolution as the period of new technology and increased food production beginning in 17th-18th century Britain (per EK SPS-5.C.1).
• Identify the three CED-named impacts: better diets, longer life expectancies, and more workers for factories (per EK SPS-5.C.1).
• Identify major innovations of the Second Agricultural Revolution (enclosure, four-field crop rotation, seed drill, selective breeding, mechanical reaper, steel plow, chemical fertilizer).
• Explain the causal link between agricultural productivity gains and the rise of the Industrial Revolution.
• Apply Skill 4.D: compare visual sources (paintings, woodcuts, technical diagrams, photographs) of agricultural change between pre-revolution and post-revolution farms.

Per CED EK SPS-5.C.1, "new technology and increased food production in the second agricultural revolution led to better diets, longer life expectancies, and more people available for work in factories." This single sentence is the core of Topic 5.4 — it identifies both the cause (technology + food production) and the three named effects (diet, life expectancy, factory labor).

Three agricultural revolutions, big picture

Geographers and historians typically identify three agricultural revolutions:

• First (Neolithic) Agricultural Revolution — ~10,000 BCE; Topic 5.3 covered this. Domestication of plants and animals; transition from hunter-gatherer to settled agriculture.
• Second Agricultural Revolution — 17th-19th centuries; this lesson. Pre-industrial and early industrial productivity gains; British agriculture as the leading edge.
• Third Agricultural Revolution (the Green Revolution) — 1940s-onward; Topic 5.5 covers this. High-yield seeds, agricultural chemicals, mechanization in the developing world.

The British Agricultural Revolution

The Second Agricultural Revolution began in 17th-century Britain and accelerated through the 18th and 19th centuries. The British case is the most studied because it directly preceded and enabled the British Industrial Revolution. Innovations spread to continental Europe and North America during the 19th century.

The agriculture-industry connection

The most important geographic insight in Topic 5.4 is the causal link between agriculture and industrialization. As agricultural productivity rose, fewer workers were needed per acre to feed a given population. The "surplus" agricultural labor migrated to industrial cities for factory work. The agriculture-industry connection runs in both directions: industry produced new agricultural tools (steel plows, mechanical reapers), and agriculture produced industrial workers and the food to feed them.

A selection of the major technical and organizational changes that drove the productivity gains.

Per CED EK SPS-5.C.1, the Second Agricultural Revolution produced three specific named impacts. Memorize all three for the AP exam.

Four cases that show the Second Agricultural Revolution and its consequences.

Britain · The Original Case

Population ~5M (1700) → ~30M (1900)

Britain is the textbook case of the Second Agricultural Revolution. The enclosure movement, four-field crop rotation, Jethro Tull's seed drill, and selective breeding all originated or matured here. The agricultural surplus enabled the British Industrial Revolution from the 1760s onward. Population sextupled while the rural agricultural workforce shrank from majority to minority.

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United States · Mechanization

McCormick reaper 1831 · John Deere steel plow 1837

The US Second Agricultural Revolution emphasized mechanization rather than enclosure (US land was already private). Cyrus McCormick's mechanical reaper (1831) and John Deere's steel plow (1837) enabled the cultivation of the vast Great Plains. By 1900, the US was the world's largest agricultural producer despite having a small share of total population in farming.

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Germany · Chemical Fertilizers

Liebig 1840s · Haber-Bosch 1909

Germany was the world leader in agricultural chemistry. Justus von Liebig's mid-19th century work established modern soil chemistry; Fritz Haber and Carl Bosch's 1909 process synthesized ammonia from atmospheric nitrogen, enabling industrial-scale nitrogen fertilizer production. Today's agricultural productivity ultimately depends on this German technical innovation.

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Japan · Meiji-Era Adoption

Meiji Restoration 1868

Japan adopted Second Agricultural Revolution technologies during the Meiji period (1868-1912) as part of its rapid modernization. Government promotion of improved seeds, fertilizers, and farming techniques boosted rice productivity. The agricultural surplus enabled Japan's rapid industrialization — the same pattern Britain had pioneered a century earlier.

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1. Per EK SPS-5.C.1, the Second Agricultural Revolution led to "more people available for work in factories." What would have happened if agriculture had not become more productive? Could the Industrial Revolution have happened anyway?
2. The enclosure movement consolidated common lands into private property. It increased agricultural productivity but displaced many rural workers. Was enclosure a net good or a net bad for English society? Defend your answer using specific evidence.
3. Britain led the Second Agricultural Revolution; other countries adopted later (US in mid-1800s, Germany in late 1800s, Japan in late 1800s). What conditions allowed Britain to be first, and what conditions enabled later adopters to catch up?
4. Per EK SPS-5.C.1, better diets and longer life expectancy were named consequences. But the displaced rural workers who moved to industrial cities often lived in slum conditions worse than what they left. How do we reconcile the two narratives?
5. The Haber-Bosch process (1909) for synthetic nitrogen is sometimes called "the most important invention of the 20th century" because it enabled the modern agricultural population. Is that judgment justified? What other innovations might rival it?

Draft alignment — pending educator review. AP HG codes correspond to the official College Board Course and Exam Description (Effective Fall 2020, V.1). Statements below are paraphrased in CountryReports' own voice; refer to the College Board's published CED for verbatim wording.

AP® and Advanced Placement® are registered trademarks of the College Board. The College Board was not involved in the production of this material and does not endorse it. Standards statements above are paraphrased; codes refer back to the official College Board CED, the NCSS C3 Framework, the Common Core State Standards, and other cited frameworks.