HSC 156 Lecture Notes - Lecture 2: Food Contaminant, Goitre, Blue Baby Syndrome
HSC 156 Study Guide for Exam #2
1. Situation in Cerrado River in South America
• Tropical Savana. Soil is not right for growing food. They add lime and phosphorus to grow
corn and soy beans. Sell them to China as a cash crop.
• Problem: Biologically diverse biome that is being destroyed because they can plant farm
crops there
2. Explain how soil texture affects water holding capacity.
• Low Permeability: BETTER because the high-top soil acts like a sponge and absorbs the
water for continuous notorious.
• High Permeability: Includes big rocks underneath the soil which allows water to slip past
3. The best type of soil for growing crops is called what?
• Loam
4. What are the root causes of erosion, and what are the immediate causes?
• Root Causes:
i. Over cultivation
ii. Overgrazing
iii. Deforestation
• Immediate Causes:
i. Wind
ii. Water
5. How do you prevent erosion?
• Crop Rotations: Grow corn, harvest corn, plant soy immediately after
• No-till or low-till Agriculture: Requires herbicides, don’t plow, reduces erosion.
• Use Organic Fertilizer: Compost
• Terrace and Contour Planting:
i. Terrace: Farm on a hill, control erosion
ii. Contour: Farm on gently sloped hills
• Wind Breaks and Strip Cropping: Trees block wind from blowing soil away
6. What is salinization and what causes it?
• Adding salt to the soil
• Causes: Using well water with high minerals, heavy irrigation, farming on top of clay
7. What is water-logging?
• Planting crops in area with high evaporation, poor drainage, and heavy irrigation.
i. The clay underneath the soil will evaporate and leaves salt at the surface.
8. What are the benefits of organic verse inorganic fertilizer?
• Organic:
i. When they break down they improve the soil
ii. Increase soils ability to hold water and nutrients
iii. Make plants stronger
• Inorganic:
i. Fast acting
ii. Releases nitrogen, phosphorous, and potassium
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9. What is Blue Baby Syndrome?
• When the fertilizer from crops get into our drinking water, babies will drink that water and
turn blue and die because there is no oxygen in the water.
• Also known as Methemoglobinemia
10. What is the difference between subsistence and industrialized agriculture?
• Subsistence:
i. Farmers of developing world use traditional agriculture methods for raising plants,
animals, and food.
ii. Large amount of land, and large amounts of human and animal labor
iii. Little money, little fossil fuel energy
• Industrialized:
i. Shifting from animal labor to machinery
ii. Increasing use of pesticides and fertilizers (some places are not getting enough rain),
Irrigation, New crop varieties
iii. Lots of land, lots of money, lots of fossil fuel energy, little labor.
11. Describe the world-wide total and per capita production of food over time.
• Total Capita: Surplus of food for everyone (enough food for everyone, not everyone gets fed)
• Per Capita: Food available per person is going down
12. Describe the environmental costs of agriculture
• Fossil Fuels: expensive and the equipment adds to pollution
• Soil Erosion: Bad farming techniques
• Resistant Pest Variations: Flow into our waterways
• Groundwater Depletion: Taking more than is available
• Water Pollution: Soil is running into our rivers
13. Explain the Green Revolution
• Introduction of Wheat and Rice (grains) into developing countries. These grains have greatly
increased crop yields
14. What is the People-Food Predicament?
• Some people can’t get food, so food can be used as a weapon.
15. Be able to correctly identify nutritional deficiency diseases in terms of their causes
• Kwashiorkor: Deficiency of protein
• Marasmus: Deficiency of protein and calories
• Xerophthalmia: Deficiency of Vitamin A
• Anemia: Deficiency of Iron
• Goiter: Deficiency of Iodine
16. What is a pest, and what is a pesticide?
• Pest: Any organism (animal, plant, microbes) which adversely affects human interests. Not
restricted to any one taxonomic group
• Pesticide: A chemical (or organic) spray that kills pests
17. List problems caused by pests
• Resource Competition
• Source of Discomfort
• Vectors of Disease
18. What % of conventionally grown (non-organic) food contained pesticide residues?
• About 70%
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