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Food, Soil, and Pest Management Chapter 12
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Core Case Study: Grains of Hope or an Illusion? Vitamin A deficiency in some developing countries leads to Blindness Death 1999: Porrykus and Beyer Genetically engineered rice with beta-carotene and more iron Is this the answer for malnutrition in these countries? Challenge of increased food production
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12-1 What Is Food Security and Why Is It Difficult to Attain? 1) Health problems due to lack of food a) Food security: Everyone in an area having daily access to enough nutritious food for healthy life b) Food insecurity: Chronic hunger & poor nutrition c) Enough food is produced for everyone to have basic needs meet, but 1-6 in developing countries don’t d) Poverty is the root of food insecurity e) other reasons: wars, corruption and political problems
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2) Chronic hunger and malnutrition a) We need a large amount of macronutrients & small amounts of micronutrients b) Hunger: mostly in developing areas, children face MR, stunted growth & dying from infectious disease c) Chronic malnutrition: deficient in proteins & other nutrients (high carb, low protein) d) Number fell from 918 mill 1970 to 862 mill 2006 e) By 25, could increase to 1.2 bill, due to corn diversion to ethanol production f) 6 million children die each yr, 16,400 per day
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3) Lack of Vitamins and minerals a) WHO estimates 1-3 suffer from a deficiency b) Anemia due to lack of iron may be reduced by golden rice c) Iodine: leads to goiters, MR stunted growth 600 mill goiters & 26 million children have brain damage
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4) Famines a) Occurs when there is a severe shortage of food b) leads to starvation, economic chaos, & social disruption c) People will eat the seed grain, which prevents planting for next season & kills the breeding stock d) usually caused by drought, flooding or war
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5) Overeating a) Overnutrition: more calories in than used b) Lowers life expectancy, susceptible to disease and illness, lower quality of life c) 1.6 billion face issues due to overnutrition d) 1-4 are overweight, 1-20 are obese e) About 66% of American Adults are overweight and 33% are obese f) We spend $50 billion to lose weight, it would only cost $24 billion to eliminate undernutrition worldwide
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12-2 How Is Food Produced? 1) Food production has increased a) 3 systems supply most of our food 1. Cropland (mostly grains) 77% (11% of land) 2. Rangeland, pastures, feedlots 16% (29% of land) 3. Fisheries 7% b) 50000 edible plants, but 14 provide 90% of food calories, 3 (corn, wheat & rice) provide 47% of calories and 42% of protein.
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c) Food specialization makes us vulnerable d) Technology has greatly increased production since 1960 2) Industrialize crop production a) Industrialized (high-input) agriculture 1. uses heavy equipment 2. Financial capital, fuel & water 3. Pesticides and fertilizer 4. produces monocultures b) Yield: amount of food per unit land
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c) high input produces about 80% of worlds food d) Plantation: 1. tropical, monoculture cash crop agriculture 2. bananas, soybeans, sugarcane, coffee, palm oil, vegetables e) Greenhouses in arid areas (high input) f) Hydroponics: plants are grown with roots in water troughs inside greenhouse, uses 1/5 to 1/10 less water than conventional farming
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Fig. 12-6, p. 282
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3) Traditional agriculture a) practiced by 2.7 billion in developing countries, 1/5 of world’s food crops b) Traditional subsistence agriculture: 1. human or animal labor 2. makes enough for family survival with some to sell or store c) Traditional intensive: 1. increase inputs 2. makes enough to sell for income
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d) Polyculture: growing several types of crops e) Slash-burn agriculture: burning & clearing forest to grow crops until soil is no good, takes 10-30 years before it is usable f) Slash & burn is not sustainable when to many people do it. Can lead to depletion and degradation of the forest. g) Low input polyculture produces higher yields than high-input monoculture
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Science Focus: Soil Is the Base of Life on Land (know this picture) Soil composition Soil formation Layers (horizons) O horizon: leaf litter A horizon: topsoil B horizon: subsoil C horizon: parent material, often bedrock Soil erosion
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4) A Closer Look at Industrialized Crop Production a) Green revolution: the increase of food production due to high input agriculture b) 3 steps 1. develop and plant monocultures 2. use large inputs of fertilizer, pesticides & water 3. Multicropping c) 2 nd green revolution: fast growing dwarf varieties of rice and wheat for tropical & subtropical climates (more food on less land)
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Fig. 12-7, p. 285 d) Percaptia production has decreased
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Case Study: Industrialized Food Production in the United States (pg 282) Agribusiness Annual sales Food production: very efficient Percent of income spent on food
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5) Crossbreeding and Genetic Engineering Can Produce New Crop Varieties a) Artificial selection: mating organisms to get desired characteristics b) First Gene revolution: very slow process (15 + yrs) and only crosses genetically similar organisms c) After 5-10 yrs, pests & disease reduce their effectiveness d) 2 nd gene revolution: Genetic engineering alters the genetic material directly to produce desirable traits, can cross species e) GMO- genetically modified organisms
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f) Page 283 Fig 12-6 shows process g) Gene splicing takes about half as long to develop and costs less h) Resistance to: heat, cold, herbicides, insect pests, parasites, viral diseases, drought and salty or acidic soil. i) Can grow faster and survive with little or no irrigation and less fertilizer and pesticides j) Drawbacks are discussed later
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6) Meat Production and Consumption Have Grown Steadily a) Rangelands produce 1/5 of meat, other is raised in feedlots & confined feeding operations b) As affluence rises demand for meat increases c) Limitations to future growth: 1. Space: already uses 30% of ice-free land 2. Grain: major food source for meat and us 3. Loss of cropland due to urbanization
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7) Fish and Shellfish Production Have Increased Dramatically a) Fishery: concentration of aquatic species suitable for commercial harvesting b) Aquaculture: Raising marine & FW fish
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c)Study found in 2007 1.25% of ocean fisheries are virtually depleted 2.52% have been fully exploited 3.Ocean fisheries could collapse by 2050 d) Energy used to catch & deliver fish is 12.5 times the energy gained by the people eating the fish e) Without subsidies, fishing could not exist f) Blue revolution: aquaculture, the fastest growing type of food production g) China raises 70% of farmed fish h) Problems: depends on grain & fishmeal & environmental impacts
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12-3 What Environmental Problems Arise from Food Production? 1) Production food has major environmental impacts a) Agriculture has a greater harmful impact than any other human activity and it may limit future production b) According to the EPA, it is responsible for ¼ of the water quality problems in the US c) Know page 286 Fig 12-9
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Fig. 12-10, p. 289
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2) Topsoil Erosion a) Movement of soil from one place to another by wind or water. b) Plants help hold soil in place c) Entire civilizations have collapsed because of mismanaged topsoil d) Flowing water is the largest cause of erosion, which can lead to gullies. e) Wind loosens and blows topsoil particles away f) Farming, clear-cutting, overgrazing and off road vehicle use increase erosion
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g) It is estimated that 1/3 of the cropland is losing soil faster than it is forming h) Harmful effects 1. loss of fertility 2. water pollution (kills fish, shellfish, clogs irrigation ditches, channels, reservoirs and lakes)
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Fig. 12-11 pg 287 Erosion
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3) Drought and Human Activities Are Degrading Drylands a) Desertification: productive potential falls by 10% or more due to drought & human activities. (Moderate 10-25, severe 25-50, very severe 50+) b) Doesn’t always cause a desert to form c) Due to global warming desertification is expected to increase
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Fig. 12-13 pg 289 Desertification
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4) Excessive Irrigation Has Serious Consequences a) Salinization: Accumulation of salt on cropland as water evaporates b) Salinization stunts crops, lowers yeild and can kill plants c) Most severe in Asia, but about ¼ of land in US d) Waterlogging: water Accumulates underground and kills plant roots
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5) There May Be Limits to Expanding the Green Revolutions a) Without high input, most green revolution plants do not produce higher yields b) High inputs cost to much for subsistence farming c) Increasing input does not continue to increase yields d) Irrigation is limited: 1. population increases faster than use of irrigation 2. depleted underground water supplies 3. wasteful use of water 4. soil salinization 5. climate change
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e) Technology (Chapter 13) can increase the amount of crop produced per drop of water f) More land? 1. most of the good cropland is already used 2. marginal land use is not sustainable 3. coastal land may be under water in future 6) Industrialized food production requires huge inputs of energy a) Cheap energy has helped industrialized agriculture
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Industrialized Food Production Requires Huge Inputs of Energy b) Currently uses 17% of commercial energy (page 290) c) Currently food produced has more energy than required to grow it, but takes 10 units of nonrenewable energy per unit of food for everything else involved 7) Food & Biofuel production decreased biodiversity a) Agrobiodiversity: plants and animals used to provide food has decreased b) Seeds are currently stored in 1400 seed banks, research centers & botanical gardens
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b) Many of these storage areas are lost by power failures, war and natural disasters c) A new ice vault is in the Norwegian Artic d) Seeds can not always be stored (potatoes) & others must be periodically replaced e) The only effective way to preserve diversity of most plants and animals is to protect the ecosystems 8) Know page 291 GMOs page 292 Feedlots page 293 Aquaculture
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Fig. 12-18, p. 294
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Fig. 12-19, p. 295
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Fig. 12-20, p. 296
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