chapter 13: food, soil conservation, and pest …us agribusiness • giant, multinational...
TRANSCRIPT
January 09, 2014
Chapter 13: Food, Soil Conservation, and Pest Management
January 09, 2014
3 major food challenges of the world:
1) Poverty (land and money)
2) Providing and distributing food
3) Accomplishing food security in an environmentally sustainable manner (soil and water)
http://www.theguardian.com/news/datablog/2012/jul/10/food-security-index
Food Security
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Root cause of hunger and malnutrition is poverty. • can't afford to grow or buy food• war and corruption can deny poor people access to
food
*Global food production has stayed ahead of population growth, but 1/6 people in developing countries cannot grow or buy the food they need.
http://www.theguardian.com/news/datablog/2012/jul/10/food-security-index
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Food Security: every person in a given area has daily access to enough nutritious food to have an active and healthy life
*Women
National Level• Government programs
> help poor help themselves> family planning> education* > jobs* > microloans> *India's National Food Security Bill
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Food Security: every person in a given area has daily access to enough nutritious food to have an active and healthy life
International Level• developing countries do not produce enough
food to feed their people, too poor to import food
• Developed nations and international lending institutions (World Bank) provide:> Technical advice> Funding
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Food Security: every person in a given area has daily access to enough nutritious food to have an active and healthy life
At all levels: Need to reduce harmful environmental effects of agriculture
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Food Security: every person in a given area has daily access to enough nutritious food to have an active and healthy life
What do people need to eat?• Macronutrients: protein, carbohydrates, fats• Micronutrients: vitamins and minerals
Chronic undernutrition or hunger: not enough food to meet basic energy need
Malnutrition: deficiencies of key nutrients• Diet of poor consists mostly of grains (low-protein,
high carbohydrate)
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Famine: severe shortage of food in an area accompanied by mass starvation, deaths, economic chaos, and social disruption• deplete seed grain stored for future crops• eat breeding livestock• mass migration
Causes• drought• flooding• war• *Sudan civil war
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Millennium Development Goal: Reduce # of hungry and malnourished people to 400 million by 2015
Statistics Today:• Increased average daily food intake calories/person
1961-2000• Reduced # chronically undernourished or
malnourished people from 918 million (1970) to 852 million (2005)
• 6 million children die/year due to under/malnutrition and increased susceptibility to disease
• 1/3 suffer from deficiency of vitamins/minerals• US: 35 million people went hungry at times mostly
due to poverty
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What are the consequences of undernutrition and malnutrition?
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Iron Deficiency• iron is a component of
hemoglobin, which transports oxygen in RBC
• anemia> fatigue> increase susceptibility to
infection> increases chance of dying
from hemorrhage in childbirth
Iodine Deficiency• Iodine essential for thyroid gland:
produces hormones to control body's metabolism.
• Stunted growth• mental retardation• goiter: swollen thyroid gland• *Iodized salt
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Possible solutions to reducing childhood deaths from hunger and malnutrition?
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Possible solutions to reducing childhood deaths from hunger and malnutrition?• Immunizations• Encouraging breast-feeding• Oral rehydration (sugar and salt in water to
prevent dehydration from diarrhea)• Vitamin A capsule• Family planning (space births 2 years)• Increasing education for women: nutrition,
drinking water sterilization, contraception, childcare
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Overnutrition: Food energy intake exceeds energy use• *Suffer similar health problems as underfed
people> lower life expectancy, more disease and
illness, lower quality of life• 60% American adults are overweight• 33% American adults are obese• 1 billion people face health problems from not
eating enough• 1.2 billion people face health problems from
eating too much
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Food Production
29% land area
11% land area
• Since 1960: Increase in global food production. *technological advances
• Challenges:> Environmental harm: pollution, irrigation,
overgrazing, overfishing, etc.)> Loss of biodiversity*
– Destruction of natural ecosystems– 14 plants and 9 animals provide 90% of
world's food– Wheat, corn, and rice provide more than
half calories
Asia, coastal areas
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Distribution of Types of Food Production
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Industrialized agriculture or high-input agriculture• uses large amounts of fossil fuel energy, water,
commercial fertilizers, and pesticides to produce monocultures and livestock animal for sale
• 1/4 cropland, produces 4/5 of world's food• Greenhouses
> *moving water• plantation agriculture: growing cash crops on large
monoculture plantations, mostly for sale in developed countries
• feedlots: Densely populated animal factories, fed grain> *waste, water, energy
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US Agribusiness• giant, multinational corporations control growing,
processing, distribution, and sale of food• 18% GDP• Efficiency
> Increase in yield/hectare– prevent forests, grasslands, wetlands from
being converted to farm> Reduced input of labor and resources (except
pesticide)• Food is cheaper
> Taxes to subsidize food producers and distributors
• Availability of cheap energy (oil) to use machines, process food, produce fertilizers and pesticides
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http://en.wikipedia.org/wiki/File:Florida_chicken_house.jpg
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http://www.globalagriculture.org/report-topics/industrial-agriculture-and-small-scale-farming.html
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*Agriculture is world's largest industry and most environmentally harmful
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Traditional agriculture• Low input polyculture• Traditional subsistence agriculture: uses mostly
human labor and animals to produce only enough crops/livestock for farm family's survival
• Traditional intensive agriculture: use more human and animal labor, fertilizer, and water to get higher yield. Produce enough food to feed family and sell
January 09, 2014
Traditional agriculture• Interplanting: Grow several crops on same plot
simultaneously> biodiversity = sustainable. Won't lose crops to
pests, weather, etc.> 4 types
1. polyvarietal cultivaton: planting plot with several genetic varieties of the same crop
2. intercropping: two or more different crops are grown at the same time on a plot (wheat and legume)
3. agroforestry/alley cropping: crops and trees grown together
4. polyculture: many different plants are planted together
« mature at different times, keep soil covered, less need for fertilizer, pesticides, herbicides
http://permaculturenews.org/2013/05/22/next-generation-polycultures/
January 09, 2014
Corn and Soy
Hedges, Kathryn. mvc-308s.jpg. 1999. Pics4Learning. 8 Jan 2014 <http://pics.tech4learning.com>
http://en.wikipedia.org/wiki/File:Soybean.USDA.jpg
How often do you eat corn and soy?
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Corn and Soy
• The US is the world's largest producer of corn (32%) and soybean (more than 50%)
84 million acres ~ size of Germany
January 09, 2014
Corn and Soy
• The US is the world's largest producer of corn (32%) and soybean (more than 50%)
• Distribution of corn use:> 40% ethanol (growing demand)> 37% feed livestock> 11% food *mostly as HFCS> 8% exported> rest for other industrial uses
• Large amounts of resource (fertilizer, water, etc.) are used, with environmental tolls
• Large demand for corn for ethanol is reducing diversity of American farms.
• Costs taxpayers: $90 billion between 1995-2010 • 88% of corn and 93% of soybeans grown in the US is
genetically modified
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Brainstorm 5 negative impacts of conventional agriculture with your elbow buddy. Be ready to share.
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Part II: Where does your food come from?
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http://www.foodemissions.com/foodemissions/Calculator.aspx
According to the EPA, the average gasoline vehicle in the US has a fuel economy of about 21 miles/gallon.• every gallon of gasoline creates about 8887 grams
of CO2
• every mile driven creates about 423 grams of CO2
We have only looked at the distance that food has traveled to get to our table, but what other impacts can food have, espeically the way it is grown, distributed, and eaten today?
January 09, 2014
Soil Erosion: movement of soil components (esp. surface litter and topsoil)
> wind and water> roots of plants anchor topsoil, prevent erosion> human activities increase soil erosion> Lose soil fertility + water pollution
• topsoil = renewal resource (slow!)
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Types of erosion:• sheet erosion• rill erosion• gully erosion
*Using a renewable resource unsustainably
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Desertification: productive potential of drylands falls by 10% or more because1. natural climate change 2. human activities that reduce or degrade topsoil
*Classified as moderate to very severe depending on drop in productivity
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Desertification affects people's livelihood:• loss of soil productivity = unable to grow food• displaces people (Dust Bowl, Midwestern US)
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Repeated irrigation can lead to salinization and waterlogging.
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Soil conservation: ways to reduce soil erosion + restore soil fertility
*Keep soil covered in vegetation! Why?
1. Conservation-tillage farming: Modern machinery can plant crops w/o disturbing the soil• Increases crop yields• raises soil carbon content• lowers use of water, pesticide, tractor fuel
January 09, 2014
Other methods of reducing soil erosion:
1. Terracing
2. Contour farming
3. Strip Croppinghttp://en.wikipedia.org/wiki/File:Terraced_fields_Sa_Pa_Vietnam.JPG
Planting on steep slopes!
Planting on slopes!
*Reduce runoff and erosion
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Other methods of reducing soil erosion:
4. cover crops
5. alley cropping
6. windbreaks or shelterbeltshttp://commons.wikimedia.org/wiki/File:2004_0609_Italian_ryegrass_cover_crop.jpg
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Fertilizer: replace nutrients that have been removed from soil from repeated crops or washed, blown, leached out of soil.
Organic fertilizer• Animal manure• green manure• compost
Commercial inorganic fertilizer• N, P, K• *doesn't replace organic matter
Other alternative: crop rotation
January 09, 2014
http://www.amusingplanet.com/2010/07/hungry-planet-what-world-eats-by-peter.html