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Published byLesley Poole Modified over 8 years ago
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Photo: ‘From the Good Earth’ by Michael Ableman
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“…a true and integrated ecological sensitivity… Without it every attempt at environmental conservation or restoration will fail.” Michael Ableman on local agricultural systems around the globe
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Global Food Needs and the Environment Presently: overall global agriculture production can meet demand. Current problem: great disparities between (and within) countries and communities - significant starvation and malnutrition - complex factors involving population growth, social inequities, political balances, environmental variation & changes Future problem: Human population growth:will likely double by 2025 Past increases in food production: More acreage in farming Higher yields per acre The future: more environmental change, genetic engineering, political instabilities and disparities???
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© 2003 John Wiley and Sons Publishers Fig 11.5 Geographic distribution of world production of a few major small grain crops.
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© 2003 John Wiley and Sons Publishers Fig 11.11 Major types of agricultural production in the United States.
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Agro-ecosystems Differences between agricultural and natural systems 1.Succession arrested at early stages - requires inputs such as labor, materials and energy 2.Monocultures are the norm in agriculture systems - disease vulnerability, reduced soil fertility 3.Simple verses complex patterns (rows)- erosion, pest problems 4.Diminished biodiversity - more pest problems 5.Cultivation (plowing) - disruption of soil building processes, erosion 6.Novel organisms via genetic engineering
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© 2003 John Wiley and Sons Publishers Fig 11.9 Bush fallow, also called milpa, fang, or swidden agriculture.
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Agricultural Assistance and Aid Famines: Every year since WW-II Many causes: local drought, political unrest, war, population growth Frequently short-term need Local production Requires less transportation Less vulnerable to global politics Many components already functioning Aid, or free food: can disrupt local agricultural economies
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Soils and Agriculture Chemical: nutrients, macro- and micro- Physical: Particle size (sand, silt, clay), Tilth, (friability, crumb structure…) Organic matter: Reservoir of nutrients Builds tilth Holds water Increases aeration Different crops do best in different soils
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© 2003 John Wiley and Sons Publishers Fig 11.6 Agricultural technologies.
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Eating Lower on the Food Chain The higher up the food chain we eat, the more production is required at the lower trophic levels (primary producers) - i.e. plant crops Humans are omnivores - we can eat plants or animals - we can eat from (a choose from) multiple trophic levels. Issues and questions: Range- and grazing-land verses crop-land Adequate sources of proteins and minerals Domestic animals for non-consumption purposes (transportation, clothing, etc.)
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