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Published byNorah Fitzgerald Modified over 8 years ago
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Agriculture Problems and Solutions…
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The Industrialization of Farming 1 st Green Revolution –1950 – 1970 –Monocultures –High Yields LARGE inputs of pesticides, fertilizers, and water
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–Multiple Cropping Increase the number of crops grown per year on a plot of land
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2 nd (and 3 rd ) Green Revolution –Introduced new varieties of crops –Gene Technology GMF’s: Genetically Modified Food
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Gone from FAMILY farms
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to FACTORY farms and AGRIBUSINESS
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No Soil…No Life…
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Problem: Erosion Conventional Tillage: Soil (crop fields) plowed in the fall which leaves soil bare during the winter/early spring –Soil is exposed to wind and rain –Vulnerable to erosion
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Water Erosion
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–Years of over-plowing + drought = Dust Bowl of the 1930’s –In some areas of the Great Plains, topsoil has decreased in thickness from 12 inches to less than 4 inches due to human activities!!
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Methods to prevent or reduce soil erosion Conservation tillage: soil is disturbed as little as possible Minimum Tillage: soil is not disturbed over the winter, it is turned over at planting time No-till: seeds/fertilizers injected into unplowed soil or cover crops (video clip!)
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Other method include… –Terracing: level steep slopes into terraces
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–Contour farming: planting/plowing in rows across slopes instead of up and down
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–Cover-crops: plant another crop immediately after harvest (Video clip!) Examples: buckwheat and rye
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–Alley cropping: (agroforestry) using strips of trees to anchor soil and block wind (windbreaks)
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Plant Perennials instead of Annuals –Perennial: a plant that lives for more than two years Examples: apples, strawberries, herbs, okra, potatoes, asparagus –Annual: a plant that only lives for one year Examples: wheat, rice, corn
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Problem: Nutrient Depletion Repeated crop harvesting depletes soil of nutrients.
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Soil from field that is tilled annually vs. tall grass prairie soil
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Calcium and Magnesium deficiency in plants
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“There is no way of growing crops or human bodies without Nitrogen” –Review… Where does nitrogen come from? And How do we get nitrogen???
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Methods to reduce nutrient depletion Conventional fertilizers: Inorganic – made commercially, not naturally –Fertilizers are inorganic compounds containing N, P, K (NPK) –To make these – Nitrogen gas is combined with Hydrogen gas under immense heat and pressure in the presence of a catalyst
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however… Need A LOT of electricity and the Hydrogen comes from coal, oil, or natural gas!!!! The process was created by a chemist who was designing poison gases for war… Industrial farming begins…
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alternatives Organic fertilizers: Derived from plants and animals –Animal manure: animal waste
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–Green manure: freshly cut or growing green vegetaton
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–Compost: organic matter (leaves, food, wastes, wood) broken down by microorganisms in soil
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–Crop rotation: plant nutrient depleting crops one year, legumes the next year Example: –Yearcrop –1corn –2soybeans –3oats –4alfalfa –Restores nutrients, keeps soil covered, reduces pest damage
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Traditional Farming Techniques: interplanting Polyvarietal: plant varieties of the same crop Intercropping: (similar to strip cropping) plant two or more crops at the same time
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Polyculture: plant many different plants together
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Other problems
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Acid Rain Damage
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Equations –(review!)
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Solution? Liming Calcium or magnesium carbonate
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Genetically Modified Foods Good or bad???
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Gene technology has come a long way…
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Some crops have been engineered to be able to withstand doses of herbicides that would otherwise kill them –Example: “Round-up Ready!”
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The “Bad”… Read from Barbara Kingsolver’s “Small Wonder”
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The “Good” Pest Resistance Improved Yield Tolerance to Biotic and Abiotic Stress Use of Marginalized Land Nutritional Benefits
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