5.1 Introduction to Agriculture

Every crop and farm animal needs certain conditions: enough warmth, enough water, a long enough growing season, and soil and slopes that can be worked. So the first question to ask about any farming region is what the climate and landforms allow.

A Mediterranean climate has hot, dry summers and mild, rainy winters. You find it around the Mediterranean Sea and also in California, central Chile, South Africa's Western Cape and southwestern Australia. Farmers there grow crops that handle summer drought, like grapes, olives, figs and citrus, and they often plant grains in the wet winter.

Tropical climates are hot all year. In wet tropical lowlands, farmers grow crops like bananas, cacao, coffee, sugarcane and oil palm, often on plantations, and some communities practice shifting cultivation. The warm, wet monsoon lands of South, Southeast and East Asia suit wet (paddy) rice, which grows in flooded fields. In dry climates where crops struggle, people raise grazing animals instead.

Technology loosens these limits but doesn't erase them. Irrigation turns deserts into farmland, as in California's Imperial Valley, and greenhouses let the Netherlands grow tomatoes and peppers far from their natural climate. Both cost money and use resources, which is part of why they show up mostly in wealthier places or for high-value crops.

Intensive agriculture means a lot of inputs (labor, machinery, fertilizer, money) on a small area of land, which usually produces a high output per acre. Extensive agriculture means few inputs spread over a large area, with a lower output per acre.

Intensive and extensive describe inputs per acre, not farm size and not whether the food is sold. A huge cattle ranch is extensive. A small rice farm in Vietnam, where a family works every square meter intensively, much of it by hand, is intensive.

Climate helps explain which practice shows up where. Nomadic herding and ranching dominate dry grasslands because the land can't support crops without irrigation, and each animal needs a lot of land to graze. Plantations cluster in the tropics because crops like cacao and oil palm need heat and steady rain.

Land cost also matters (you'll see this in 5.6 and 5.8). Near cities, land is expensive, so farmers need to earn a lot from each acre, which favors intensive uses like market gardening. Far from cities, cheap land makes extensive uses like ranching pay off.