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Agriculture

Agriculture. Agriculture.

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Agriculture

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  1. Agriculture

  2. Agriculture Before the invention of agriculture, all humans probably obtain the food they needed for survival by hunting for animals, fishing, or gathering plants (including berries, nuts, fruits, and roots). Hunters and gatherers lived in small groups, usually fewer than 50 persons, because a larger number would quickly exhaust the available resources within walking distance. Agriculture = deliberate modification of Earth’s surface through cultivation of plants and rearing and of animals to obtain sustenance or economic gain. vegetative planting (root crops) = the reproduction of plants by direct cloning from existing plants, such as cutting stems and dividing roots [Cassava (manioc or yucca), yams, sweet potatoes] Seed agriculture = the reproduction of plants through annual planting of seeds that result from sexual fertilization

  3. First Agricultural Revolution Geographer Carl Sauer Studied the agricultural hearths

  4. First Agricultural Revolution • To establish agriculture and settle in one place would require lands of plenty • Reliable sources of food to allow for experimentation with the cultivation of plants (agriculture) and the domestication of animals • First root cropping: 14,000 years ago – Southeast and South Asia • Human settlements • Forest margins • Freshwater streams

  5. First Agricultural Revolution First seed agriculture: Southwest Asia (Fertile Crescent)

  6. First Agricultural Revolution Region 1 taro yams bananas Region 4 wheat barley other grains Region 6 maize(corn) squashes Several beans

  7. Second Agricultural Revolution • 17th through early 19th centuries • Motivations: Little Ice Age (1300-1750 varied with worst of it in the last 100 years) • Advances in agriculture allowed for the move beyond subsistence to generate the kinds of surplus needed to feed thousands of people working in factories instead of in agricultural fields • Diffusion of crops from America to Europe including corn and potatoes • New methods instituted: field rotation, fertilization • New technology: seed drill, railroad, internal combustible engine, tractors, etc. • Economics: banking and lending

  8. Third Agricultural Revolution: GREEN REVOLUTION • Started in the 1930s • Agricultural scientists experimented with technologically manipulated seed varieties to increase crop yields • Hybridization of grains to increase yield, pest resistance and heartiness • Focused on rice, wheat, and corn • More recently cassava and sorghum • Dangers of genetically engineered foods • Unknown health risks • Environmental concerns of pollen dispersal, soil pollution • Reduce genetic diversity • Evolution of super-pests • Economically out of reach for small farmers

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