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Human Geography Unit 5: Agriculture and rural land-use patterns and processes

Agriculture has changed through several revolutions, and its patterns are shaped by climate, distance to market and global systems.

Covers: Agricultural origins and hearths, agricultural practices, rural settlement, agricultural revolutions, the von Thünen model, global food systems, challenges

Study guide

Agriculture began in several hearths, including the Fertile Crescent, Mesoamerica, East Asia and the Andes. The First Agricultural Revolution (Neolithic Revolution) domesticated plants and animals, leading to permanent settlements. The Second Agricultural Revolution, tied to the Industrial Revolution, introduced new tools, crop rotation and better transportation. The Third Agricultural Revolution, or Green Revolution, used high-yield seeds, fertilizers, pesticides and irrigation to boost yields, especially in Asia and Latin America, though it increased reliance on chemicals and water. Today, genetically modified organisms (GMOs) and biotechnology continue the trend.

Agriculture can be subsistence (growing food for one's family) or commercial (growing for sale). Intensive agriculture uses a lot of labor or capital on a small area, like market gardening, plantations and rice farming. Extensive agriculture uses less labor or capital on large areas, like shifting cultivation (slash-and-burn), nomadic herding and ranching. Pastoral nomadism moves herds across dry lands, and transhumance moves herds seasonally between mountains and valleys. Rural settlement patterns can be clustered, dispersed or linear, and land survey systems include metes and bounds (natural features), township and range (a grid) and long lots (narrow strips along rivers).

The von Thünen model explains rural land use by distance to market. Rings around a city are, from closest to farthest: intensive farming and dairy (perishable goods), forest (for fuel and building), field crops like grain, and ranching. Today agriculture is a global system. Agribusiness integrates production, processing and distribution, commodity chains connect farms to consumers, and many countries depend on export crops. Challenges include food deserts (areas lacking healthy, affordable food), soil erosion, desertification, water use, loss of biodiversity and debates over GMOs and organic farming. Sustainable practices include crop rotation, no-till farming and agroforestry.

Under comparative advantage, places specialize in producing what they can make at the lowest relative cost and trade for the rest. For example, Paraguay and Brazil specialize in soybeans and import manufactured goods. This regional specialization makes countries interdependent, so a drought or price change in one region affects food supplies and incomes in others. The Green Revolution's seeds, fertilizer and irrigation are expensive, so they favored wealthier farmers with more land and credit. Many small farmers fell into debt or lost their land, which widened rural inequality and pushed people to migrate to cities. It sharply reduced famine in Asia but had much less effect in sub-Saharan Africa.

Refrigerated shipping, containers and better roads let farms sell to distant markets, so large farms can grow one crop on a huge scale at a lower cost per unit (economies of scale). Cheap surplus food from subsidized farms in wealthy countries can undercut local farmers in developing countries. Whether farming is intensive or extensive depends on land cost, labor and capital. Where land is scarce and labor is cheap, as in many less developed countries, farmers use a lot of labor on small plots. Where land is plentiful and labor is expensive, as in the US Great Plains, farmers use machinery on large areas with few workers.

The Columbian Exchange, after 1492, moved crops and animals between the Americas and the rest of the world. Potatoes, corn, tomatoes and cassava spread to Europe, Africa and Asia, while wheat, cattle, pigs and horses came to the Americas. It is a major example of relocation diffusion of agriculture. Concentrated animal feeding operations (CAFOs) produce large amounts of manure that can pollute water, along with methane that adds to climate change. Clearing land for pasture and feed crops drives deforestation, especially in the Amazon. Monoculture, planting one crop over large areas, reduces biodiversity and makes fields more vulnerable to pests.

Key ideas

• Agriculture began in several hearths during the Neolithic Revolution.
• The Green Revolution raised yields with new seeds and chemicals.
• Intensive farming uses more labor or capital on less land.
• The von Thünen model ranks land use by distance to market.
• Global agribusiness links farms to consumers through commodity chains.

Formulas and rules

Common mistakes

• Confusing intensive (high input per area) with extensive (low input, large area).
• Thinking von Thünen's forest ring is farthest out; ranching is.

Words to know

Agricultural hearth

A region where farming first developed.

Neolithic Revolution

The first domestication of plants and animals.

Second Agricultural Revolution

Farming improvements tied to industrialization.

Green Revolution

Use of high-yield seeds, fertilizers and irrigation.

GMO

A genetically modified organism.

Subsistence agriculture

Growing food mainly for one's own family.

Commercial agriculture

Growing crops or animals for sale.

Intensive agriculture

High labor or capital inputs on a small area.

Extensive agriculture

Low labor or capital inputs on a large area.

Shifting cultivation

Clearing land by burning, farming it, then moving on.

Pastoral nomadism

Herding animals across large, dry areas.

Transhumance

Seasonal movement of herds between mountains and valleys.

Metes and bounds

Land survey system using natural features.

Township and range

Land survey system using a grid.

Von Thünen model

Model of agricultural land use based on distance to market.

Agribusiness

Large-scale, integrated commercial agriculture.

Commodity chain

The steps from producing a good to selling it.

Food desert

An area lacking access to affordable, healthy food.

Desertification

Land degrading into desert.

Sample practice questions

5 more questions like these, from level 1 to 5, are in the practice set.