L17 - NATS 1840 Lecture 18 Modern Agriculture and the...

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NATS 1840 Lecture 18 – Modern Agriculture and the Environment - 20 th century transformation of agriculture - Early 20 th century - gas powered tractor and horses - Transfer of land use, additional 16 million people fed - Steam and internal combustion combine harvesters - 1930’s rural American electrification - Crossbreeding of plants, longer life, pest resistance, more productive - Selective breeding for ease of harvesting - tomatoes - reduction of biodiversity, disease and disaster - Pesticides, herbicides and chemical fertilizers - Pesticide industry, heavy investment in chemistry R+D, science-based industry Pesticides - 2.5 million tons of pesticides per year worldwide, 20 billion cost - 37% of all food and fibre crops are destroyed - Losses without pesticides estimated at 47% - 10 fold increase in pesticide use between 1945 and 1989 - Continuous production of crops leads to increased losses - Pesticides and crop returns, wider costs - efficiency and production, social and environmental costs
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L17 - NATS 1840 Lecture 18 Modern Agriculture and the...

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