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Land and Water Use

Land and Water Use

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Land and Water Use

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  1. Land and Water Use

  2. Feeding a growing Population

  3. Human Nutritional Requirements

  4. Human Nutritional Requirements • Calories • Male • Female • Nutrition • Protein: • Carbohydrate: • Fat:

  5. Human Nutritional Requirements • Food source • 100 species of plants (350,000 available) • Wheat and rice supply over half human Calories • 8 animal species supply 90% of world’s needs

  6. Types of Agriculture

  7. Types of Agriculture • Soil Prep • High input: • Subsistence: • Tillage: • Low Till, no till:

  8. Types of Agriculture • Crop type • Crop Rotation: • Monoculture: • Polyculture:

  9. Green Revolution • 1950-1970 • 1970

  10. Genetically Engineered Crops • 75% of all crops are genetically engineered • Pest, drought, mold, salinity resistance • Higher protein yield • Higher vitamin content

  11. Genetically Engineered Crops Pros Cons

  12. Sustainable Agriculture

  13. Main Goals

  14. Efficient Use of Inputs

  15. Selection of Site, Species, and Variety • Pest-resistant crops • Location (climate, topography) • Soil type and depth • Previous crop history • “Do your homework”

  16. Species Diversity • Reduces economic risk • Can improve soil • Optimum diversity – livestock and crops

  17. Soil Management • Reduces need for: • Reduces issues:

  18. Soil Management • Managing Soil • Cover crops • Compost/manure • Reduce tillage • Maintain soil cover – plants/mulch • Regular additions of organic matter

  19. Relevant Laws • Conservation Reserve Program (CRP) 1985 • Farmers paid for land placed in reserve • Food Security Act 1985 • Farmers must develop and implement soil conservation programs to remain eligible for subsidies, etc. • 2002 Farm Security and Rural Investment Act • Subsidies: price supports and farm income

  20. Controlling Pests

  21. Types of Pesticides • How pesticides differ

  22. Types of Pesticides • Biological • Living organisms • Ladybugs • Carbamates (urethanes) • Affect nervous system • Very water soluble • Potent (100g = 2000g DDT)

  23. Types of Pesticides • Chlorinated hydrocarbons (DDT) • Affect nervous system • Persistent • Can remain in ecosystemfor up to 15 years • Fumigants • Sterilize soil • Prevent pest infestation of stored grain

  24. Types of Pesticides • Inorganic – mercury, lead, copper • Highly toxic • Accumulate • Organics (natural) • Derived from plants (chrysanthemum)

  25. Types of Pesticides • Organophosphates - Dursban • Extremely toxic – affects nervous system • Not persistent in environment

  26. Costs and Benefits • Many pests have increased in numbers

  27. Pros of Pesticides • Kill unwanted pests that cause disease • Increased food supplies • More food means less expensive • Newer pesticides are safer and more specific • Reduced labor cost • Agriculture is more profitable

  28. Cons of Pesticides • Accumulate in food chains • Pests develop resistance • $5-10 in damage done environmentally for every $1 spent • Expensive • Biomagnification in aquatic environments (runoff) • Ineffective – only 5% reaches a pest • Threatens endangered species, pollinators, human health

  29. Integrated Pest Management (IPM) • Pest control strategy that uses many methods • Reduce or eliminate traditional pesticides • Goal is to control numbers, not eradicate

  30. Relevant Laws • Federal Insecticide, Fungicide, & Rodenticide Control Act (FIFRA) 1947 • Regulates manufacture and use of pesticides • Federal Environmental Pesticides Control Act 1972 • Requires registration of all pesticides in US commerce

  31. Relevant Laws • Food Quality Protection Act 1996 • Emphasizes protection of infants and children in reference to pesticide residue in food

  32. Irrigation

  33. Irrigation • ¾ of all freshwater • Use depends on climate and industrialization • Up to 70% of irrigation water is lost

  34. Drip irrigation • Reduces water loss through evaporation • Expensive to install • Used on 1% of crops worldwide

  35. Sustainable Irrigation Limits • Increased costs • Depletion of current sources • Competition from urban areas • Restoration of wetlands and fisheries • Salinization