Chapter 12: Chapter 12 Food Resources


Food in the World: Food in the World 30,000 plant species with parts people can eat 15 plants and 8 animals supply 90% of our food Wheat, rice, and corn are half the calories people eat 66% of people eat mainly rice, wheat, and corn (grains) The top third of the economic chain eats primarily meat. www.iia.msu.edu/absp/ drought_00.html


Types of Food Production: Types of Food Production Industrialized agriculture Traditional agriculture www.orknet.co.uk/welsby/ farming.htm


Industrialized Agriculture: Industrialized Agriculture Industrialized agriculture-Use large amounts of fossil fuel energy, water, commercial fertilizers and pesticides to produce huge quantities of single crops or livestock animals for sale. www.alaskajournal.com/.../ foc_20030804021.


Traditional Agriculture: Traditional Agriculture Traditional agriculture-practiced by 2.7 people on earth Traditonal subsistence agriculture-produce enough food to stay alive Traditional Intensive agriculture-farmers increase inputs of human and draft labor, fertilizer and water to get a higher yield per area of cultivated land to produce enough food for families, and their income members.aol.com/ porkchopsplace/


Green Revolution: Green Revolution Involves 3 steps 1. Developing and planting monocultures of selectively bred or genetically engingeered high yeid varieties of key crops 2. Lavishing fertilizer, pesticides, and water on crops to produce high yeilds 3. Often increasing the intensity and frequency of cropping


Food Production in the U.S.: Food Production in the U.S. Since 1940, food production in the U.S. has more than doubled crop production 9% of population is involved in the U.S. agricultural system. Generates 18% of countries GNP


Livestock Production: Livestock Production Meat products are sources of quality protein. Between 1950 and 1996, world mead production increased fourfold and per capita meat production rose by 29%. 14% of U.S. topsoil is associated with livestock grazing. Cattle belch out 12-15% of all the methane released into the atmosphere Some say if Americans cut their grain intake by 16%, this would save enough grain to provide a subsistence diet for nearly 900 million people. about.reuters.com/ids/products/ onlinerep.htm


Interplanting: Interplanting Polyvarietal cultivation-Where plot is planted with several varieties of the same crop Intercropping-two or more different crops grown at same time on a plot Agroforestry- Crops and trees are planted together Polyculture-Many different plants mature at various times, and are planted together.


World Food Problems: World Food Problems Reasons for problems: Population growth Increasing affluence Degradation and loss of cropland Little growth in irrigation Decline in global fertilizer


Undernutrition: Undernutrition Undernutrition-Consuming insuffieciet food to meet one’s minimum daily energy requirement for a long enough time to cause harmful effects www.hellfirepass.com/ index_pow.htm


Malnutrition: Malnutrition Malnutrition-Faulty nutrition. Caused by a diet that does not supply a persons with enough protein, essential fats, vitamins, minerals, and other nutrients.


Overnutrition: Overnutrition Overnutrition-an excessive intake of food, especially fats fulton.edzone.net/winkler/ chapter05/chapter05.htm


Good News!: Good News! Between 1970 and 1995, worldwide proportion of people suffering from undernutrion went from 36% to 14%. Number of malnourished people fell from 940 million in 1970 to 850 million in 1995. We produce more than enough food to meet the basic nutritional needs of every person on earth today


Environmental Effects of Producing Food: Environmental Effects of Producing Food Agriculture has a greater harmful impact on air, soil, water, and biodiversity resources than any other human activity. ptcl.chem.ox.ac.uk/MSDS/HY/ hydrochloric_acid.html


Increasing Crop Yields: Increasing Crop Yields Agricultraul experts expect most future increases in food yields per hectare on existing cropland to result from improved strains of plants and from expansion of green revolution technology


Cultivation of Land: Cultivation of Land 36% of the world’s land is devoted to raising crops. Some think that cultivating more land is a possible solution to the food crisis. www.cahe.nmsu.edu/ employee/cca/


Food Growth in Urban Areas: Food Growth in Urban Areas Urban gardens provide 15% of world’s food. If people grew more food in their backyards, they could live more sustainable and save money.


Fishing: Fishing 3rd major food producing system consists of fisheries 99% of fish caught in ocean is from the coastal waters Between 1950 and 1996, fish catch increased 4.9 fold www.starfish.govt.nz/social/ facts/fact-letsgo.htm


Problems With Fishing: Problems With Fishing Overfishing-Taking of so many fish that too little breeding stock is left to maintain numbers Commercial extinction-reduction of a species to the point at which it’s no longer profitable to hunt for them


Aquaculture: Aquaculture Aquaculture-where fish and shellfish are raised for food Supplies 20% of world’s commercial food harvest Increased 3.3 fold between 1984 and 1996 www.un.org/.../portuguese/ 2003/aug/030811.html


Gov. assistance to farmers and consumers: Gov. assistance to farmers and consumers Keep food prices low Give farmers subsidies to keep them in business and to encourage them to increase food production Eliminate most or all price controls and subsidies Continue Agricultural research


Sustainable Agricultural: Sustainable Agricultural Sustainable Agricultural-Method of growing crops and raising livestock based on organic fertilizers, soil conservation, water conservation, biological control of pests, and minimal use of nonrenewable fossil fuel energy www.sare.org/htdocs/ sare/about.html


Bibliography: Bibliography Miller, Tyler G. Living in the Environment, Brooks/Cole Publishing Company, New York: 2000.


Chapter 21: Chapter 21 Protecting Food Resources: Pesticides and Pest Control


Pesticides: Types and Uses: Pesticides: Types and Uses What is a Pest? A pest is any species that competes with us for food, invades lawns and gardens, destroys wood in houses, spreads disease, or is simply a nuisance Most of the time nature takes care of the pests through natural enemies (predators, parasites, and disease organisms)


So what’s a Pesticide?: So what’s a Pesticide? Pesticides (also known as biocides) are chemicals that are to kill organisms we consider undesirable ex. – insecticides, herbicides, fungicides, nematocides, and rodenticides


Slide28: Above: Worker prepares his vehicle for a day of pesticide spraying


Coevolution: Coevolution For almost 225 million years, plants have been producing chemicals to ward off or poison herbivores that feed on them… But, through what is known as coevolution, the predators overcome various plant defenses by natural selection and the plants must develop new defenses


First Attempts at Pesticides: First Attempts at Pesticides Sulfur (early 500 BC) Toxic compounds of arsenic, lead, and mercury (1400’s) Abandoned in late 1920’s when the increasing number of human poisonings increased Nicotine Sulfate (1600’s) Pyrethrum and Rotenone (mid-1800’s)


Paul Mueller and the Second Generation: Paul Mueller and the Second Generation In 1939 Paul Mueller discovered that DDT, a chemical known since 1874, was in fact a potent insecticide. DDT became the first pesticide of the so-called Second Generation Pesticides. Mueller went on to win the Nobel Prize in 1948 for his discovery.


Pesticides Today: Pesticides Today Chemists have been developing hundreds of synthetic organic chemicals for use as pesticides Worldwide about 2.3 million metric tons of pesticides are used yearly 1 lb for each person on earth 75% in developed countries (Latin America, Asia and Africa on the rise) 1996 world sales = $30 billion($11 billion: US)


Slide33: Spray those fields


Here in the US: Here in the US About 630 different biologically active (pest killing) ingredients and about 1,820 inert (inactive) ingredients are mixed to make some 25,000 different pesticide products in the United States


Pesticide Distribution in US: Pesticide Distribution in US Cultivation of two crops Cotton (55%) Corn (35%) Used about 90% of the insecticides and 80% of the herbicides applied to crops in the United States in 1995


Slide36: Example of Solid Pesticides


More Distribution: More Distribution 25% of the pesticide use in the United States is for ridding houses, gardens, lawns, parks, playing fields, swimming pools, and golf courses of unwanted pests Average lawn in US = 10x’s more pesticides per hectare than US cropland Each year = 250,000 residents become ill


Some Quick Facts: Some Quick Facts Broad-Spectrum agents : toxic to many species Selective or Narrow spectrum agents : effective against a narrowly defined group of organisms Pesticides vary in persistence (length of time they remain deadly in environment)


The Pros: The Pros Pesticides save human lives: has prevented premature births due to malaria, bubonic plague, typhus, sleeping sickness (all carried by pests) Pesticides increase food supplies and lower food costs: 55% of crop lost before harvest due to pests Pesticides increase profits for farmers: every $1 spent on pesticides yields worth approximately $4 (although dropped to $2 if harmful effects)


Slide40: Farmers in all countries have tried pesticides to save there crops


More Pros: More Pros Pesticides work faster and better than alternatives: Pesticides can control pests quickly and at a reasonable cost. Long shelf life and easily shipped and applied Health risks insignificant when compared to their benefits Safer more effective pesticides are being developed New pesticides are being used in less rates per unit when compared to older products


Ultimate Goal of Pesticides: Ultimate Goal of Pesticides Kill only the target pest Harm no other species Disappear or break down into something harmless after doing its job Not cause genetic resistance in target Be cheaper than doing nothing


The Cons: The Cons Genetic Resistance: pest organisms develop resistance to the pesticide after a short period of being exposed to it Broad-Spectrum insecticides kill natural predators and parasites that may have been maintaining the population of a pest species at a reasonable level Ex. Wolf spiders, wasps, predatory beetles…


Cons continued…: Cons continued… Because natural predators can be wiped out; this may unleash new pests whose populations the predators had previously held in check


In Our Water: In Our Water Testing in rivers and water reveal that pesticides have strayed away from there targets and found there way into the waters


Pesticide Treadmill: Pesticide Treadmill As pests become resistant to the pesticides, sales reps for the pesticide recommend larger doses or more frequent application As a result farmers end up on a pesticide treadmill where they end up paying more and more for a pest control program that often becomes less and less effective


Example of Pesticide Treadmill: Example of Pesticide Treadmill In Central America, cotton growers increased the frequency of insecticide applications from 10 to 40 times per growing season. Still, declining yields and falling profits forced many of the farmers into bankruptcy


Where does it all go?: Where does it all go? Only about 2% of the sprayed insecticide by air reaches target pests Less than 5% of herbicides applied reach target weed Pesticides that don’t reach there target end up in the air, surface water, groundwater, bottom sediments, food and other nontarget organisms


Continued: Continued Still, pesticide waste can be reduced by using recirculating sprayers, covering spray booms, and using rope-wick applicators


DDT: DDT Banned in 1972 by US 1980 high levels in peregrine falcon and the osprey EPA found DDT in 99% of the freshwater fish it tested DDT drifts from other countries still using it


Slide51: Checking for pesticide residue in food


Regulation in the US: Regulation in the US All commercial pesticides must be approved by EPA EPA reviews each pesticide EPA sets tolerance levels : amount of toxic pesticide residue that can legally remain on crop No longer has to test on birds and fish 55 active pesticides banned in US, but may be used and shipped elsewhere


More Regulations: More Regulations National Academy of Sciences says that the federal laws are not adequate 98% of potential risk of cancer would be eliminated if pesticide residue on food eliminated by government Approximately $1 Billion spent on regulating pesticides each year


1996 Food Quality Protection Act: 1996 Food Quality Protection Act Requires food to have only reasonable levels of pesticide tolerance It requires manufacturers to demonstrate that the active ingredients in there products are safe for infants and children Requires EPA to consider exposure to more thatn one pesticide when setting pesticide tolerance levels EPA develops program to screen ingredients


From Above: From Above Just one of the many ways that pesticides are being applied are through aerial drops of the chemicals


Other Solutions: Other Solutions Crop rotations Planting times can be adjusted Plowing at night (reduces weeds) Plant where major pests do not exist Switch away from monoculture to intercropping, agroforestry, and polyculture


More Solutions: More Solutions Plants and animals that are genetically resistant to certain pest insects, fungi and diseases can be developed - downside: costly Biological control: predators and pathogens 300 biological pest control successful in China and Cuba Biological Control: non-toxic to humans Downside: timely


Slide58: Pesticides are plentiful as seen here and it comes in many different forms


Even more Solutions…: Even more Solutions… Plant toxins Bt toxin used to kill thousands of strain of common soil bacterium Insect Birth Control (sterile male approach) Aqua heat: spray boiling water on crops


Yes… more solutions: Yes… more solutions Some crops can be exposed to gamma rays after harvest Extends shelf life Critics say irradiating food destroys vitamins and other nutrients Increases death from botulism poisoning Picowaved stickers on food that has been


IPM: IPM Integrated Pest Management Goal is reduction of crop damage t an economically tolerable level Carefully monitor damage levels of pests When reached, farmers first use biological methods Small amounts of insecticides are used as a last resort


Pesticides in Politics: Pesticides in Politics Pesticides have been a big issue with environmentally safe activists. It is a big topic the EPA has to deal with


Bibliography: Bibliography Miller, Tyler G. Living in the Environment, Brooks/Cole Publishing Company, New York: 2000.


Fin: Fin David Chew Joe Yi Period 5