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Food, Soil, and Pest Management. Chapter 12. 12-1 What Is Food Security and Why Is It Difficult to Attain?.
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Food, Soil, and Pest Management Chapter 12
12-1 What Is Food Security and Why Is It Difficult to Attain? • Concept 12-1A Many of the poor suffer health problems from chronic lack of food and poor nutrition, while many people in developed countries have health problems from eating too much food. • Concept 12-1B The greatest obstacles to providing enough food for everyone are poverty, political upheaval, corruption, war, and the harmful environmental effects of food production.
Many of the Poor Have Health Problems Because They Do Not Get Enough to Eat • Food security – means that every person in a given area has daily access to enough nutritious food to have an active and healthy life. • Global food production has stayed ahead of population growth. • However : • One of six people in developing countries cannot grow or buy the food they need. • Food insecurity – living with chronic hunger and poor nutrition.
Key Nutrients for a Healthy Human Life • We need large amounts of macronutrients • (protein, carbohydrates, and fats) • We also need smaller amounts of micronutrients • (vitamins such as A,C, and E and various minerals)
Many People Suffer from Chronic Hunger and Malnutrition • Some people cannot meet their basic energy needs • Chronic undernutrition or hunger • Others lack proteins and key nutrient needs • Chronic malnutrition • The root cause of hunger and malnutrition is poverty. • In 2006, 862 million were undernourished worldwide. • A 2005 estimate says 6 million children die annually from undernutrition or nonfatal diseases made worse by their poor diet.
Many People Do No Get Enough Vitamins and Minerals • One in three people has a deficiency of one or more vitamins and minerals, especially: • iron – anemia • vitamin A – blindness • iodine – goiter or enlarged thyroid gland • Can lead to deafness • Famine – a shortage of food in an area along with mass starvation, economic and social chaos • Usually caused by crop failures from drought, flooding, war, or other catastrophic events
Many People Have Health Problems from Eating Too Much • Overnutrition – excess calories and lack of exercise can lead to reduced life quality, poor health, and premature death…same as undernutrition • A 2005 Boston University study: • 60% of American adults are overweight • 33% are obese • Americans spend $42 billion a year trying to lose weight. • Estimates are that $24 billion per year would eliminate world hunger.
12-2 How Is Food Produced? • Concept 12-2A We have sharply increased crop production using a mix of industrialized and traditional agriculture. • Concept 12-2B We have used industrialized and traditional methods to greatly increase supplies of meat, fish, and shellfish.
Food Production Has Increased Dramatically • Wheat, rice, and corn provide more than half of the world’s consumed calories • Fish and shellfish are an important source of food for about 1 billion people mostly in Asia • Of all the biodiversity on the planet, only 14 plantand 9 animalspecies make up 90% of the world’s consumed calories.
Food Production Has Increased Dramatically • Three systems produce most of our food: • Grain from croplands: 77% • Meat from rangelands, pastures, and feedlots: 16% • Fish from fisheries/Aquaculture: 7% • Dramatic increase in global food production since 1960. • Why? • Technological advances • More sophisticated farming techniques • Expanded use of inorganic chemical fertilizers, irrigation, pesticides, high-yield crops • Intense farming methods, densely populated feedlots, breeding/growing pens, aquaculture ponds or ocean cages
Two Types of Agriculture • Industrial Agriculture(High Input Agriculture) • A relatively small group of farmers produce large quantities of a single crop or livestock • Mostly in developed countries • Traditional Agriculture (Low Input Agriculture) • Traditional subsistence agriculture • Produces enough crops or livestock to feed family • Traditional intensive agriculture • Produces enough crops or livestock to feed the farmer’s family and maybe some to sell • Mostly in developing countries
Industrialized Crop Production Relies on High-Input Monocultures • About 80% of the world’s food supply is produced by industrialized agriculture. • Goal is to steadily increase crop yield • Uses large amounts of fossil fuel energy, water, commercial fertilizers, and pesticides to produce monocultures. • Plantation agricultureprimarily in tropical developing countries (bananas, coffee, sugarcane) • Cash crops – crops intended for sale, not consumption or animals
Traditional Agriculture Often Relies on Low-Input Polycultures • Many farmers in developing countries grow a variety of crops on the same plot of land • Polyculture: different plants are grown together • Limited technology, limited equipment, limited impact on the environment • Slash-and-burn agriculture – burning underbrush to provide nutrients to the soil
A Closer Look at Industrialized Crop Production • The Green Revolution represents the 88% increase in food production per unit of area since 1950. • Monocultures of high-yield key crops • Selectively breed or genetically engineered crops • Large inputs of fertilizers, pesticides, water • The Second Green Revolution involves fast growing rice/wheat bred for tropical regions. • Early in the century, one American farmer could produce food for 2.5 people. • By 1999, a single farmer could feed over 130 people.
A Closer Look at Industrialized Crop Production • Since 1950, high-input agriculture has produced more crops per unit of land. • Grain production has tripled during this timeframe • Why has per Capita grain production gone down since the early 1980’s?
Crossbreeding and Genetic Engineering Can Produce New Crop Varieties • Gene Revolution – increased crop yields, as a result of mixing organisms’ genes • Artificial selection has been used for centuries to develop genetically improved varieties of crops. • Genetic engineering develops improved strains at an exponential pace compared to artificial selection. • Add beneficial genes • Delete negative genes
Crossbreeding and Genetic Engineering Can Produce New Crop Varieties • Age of Genetic Engineering • developing crops that are resistant to: • Heat and cold • Herbicides • Insect pests • Viral diseases • Drought • Salty or acidic soil • Controversy has arisen over the use of genetically modified foods (GMF’s). • Critics fear that we know too little about the long-term potential harm to human health and the environment.
Meat Production and Consumption Have Grown Steadily • Meat production increased fourfold from 1961–2007 • Industrialized livestock production: • Densely populated feedlots are common • System uses a lot of energy and water and produce huge amounts of animal waste
Industrialized Meat Production Has Harmful Environmental Consequences
Fish and Shellfish Production Have Increased Dramatically • Aquaculture – raising large numbers of fish and shellfish in ponds and cages • world’s fastest growing type of food production. • Fish farming involves cultivating fish in a controlled environment and harvesting them in captivity.
Producing Fish Through Aquaculture Can Harm Aquatic Ecosystems
12-3 What Environmental Problems Arise from Food Production? • Concept 12-3 Food production in the future may be limited by its serious environmental impacts, including soil erosion and degradation, desertification, water and air pollution, greenhouse gas emissions, and degradation and destruction of biodiversity.
Producing Food Has Major Environmental Impacts • Modern agriculture has a greater harmful environmental impact than any human activity. • Loss of biodiversity as a result of monocultures • Loss of genetic variability in crops and livestock • High input of chemicals • Air, water pollution • Greater soil erosion
Topsoil Erosion Is a Serious Problem in Parts of the World • Soil erosion is the movement of soil components, especially surface litter and topsoil, by wind or water. • Soil erosion increases through activities such as farming, logging, construction, overgrazing, and off-road vehicles. • Soil erosion lowers soil fertility and can overload nearby bodies of water with eroded sediment.
Topsoil Erosion Is a Serious Problem in Parts of the World • Soil is eroding faster than it is forming on more than one-third of the world’s cropland.
Excessive Irrigation Has Serious Consequences • Irrigation problems: • Salinization – repeated irrigation can reduce crop yields by causing salt buildup in the soil • Waterlogging
Natural Capital Degradation: Desertification of Arid and Semiarid Lands
Industrialized Food Production Requires Huge Inputs of Energy • Industrialized agriculture uses about 17% of all commercial energy in the U.S. and food travels an average 2,400 kilometers from farm to plate.
12-4 How Can We Protect Crops from Pests More Sustainably? • Concept 12-4 We can sharply cut pesticide use without decreasing crop yields by using a mix of cultivation techniques, biological pest controls, and small amounts of selected chemical pesticides as a last resort (integrated pest management).
We Use Pesticides to Try to Control Pest Populations • What is a pest? • Only about 100 species of plants (weeds), animals (mostly insects), fungi, microbes cause the most damage • Chemists have developed hundreds of chemicals (pesticides) that can kill or repel pests. • Pesticides • Insecticides • Herbicides • Fungicides • Rodenticides • 2.6 million tons of pesticides (600 different active chemicals) used annually
We Use Pesticides to Try to Control Pest Populations • First-generation pesticides • Natural chemicals derived from plants • Second-generation pesticides • Man-made chemicals from a laboratory • DDT was the first • Broad-spectrum agents • Toxic to many pest and non-pest species • Narrow-spectrum agents • Effective against a specific group of species • Pesticides vary in their persistence • How long they remain deadly in the environment
The ideal pest-killing chemical has these qualities: Kill only target pest Not cause genetic resistance in the target organism Disappear/break down into harmless chemicals after doing its job Be more cost-effective than doing nothing We Use Pesticides to Try to Control Pest Populations
Modern Synthetic Pesticides Have Several Advantages/Disadvantages • Each year > 250,000 people in the U.S. become ill from household pesticides
The Environmental Protection Agency (EPA), the U.S. Department of Agriculture (USDA), and the Food and Drug Administration (FDA) regulate the sale and use of pesticides under theFederal Insecticide, Fungicide and Rodenticide Act(FIFRA). The EPA has only evaluated the health effects of 10% of the active ingredients of all pesticides. Cite lack of funding for complex and lengthy project The Food Quality Protection Actstrengthens FIFRA by reducing the allowable level of chemicals by a factor of 10 for which the health effects are still unknown. Precautionary Principle Laws and Treaties Can Help to Protect Us from the Harmful Effects of Pesticides
There are Alternatives to Using Pesticides There are cultivation, biological, and ecological alternatives to conventional chemical pesticides. Fool the pest through cultivation practices. Biological pest control Provide homes for the pest enemies. Bring in natural enemies. Use pheromones to lure pests into traps. Use hormones to disrupt life cycles. Implant genetic resistance into plants. Both tomato plants were exposed to destructive caterpillars. The genetically altered plant (right) shows little damage.
Integrated Pest Management Is a Component of Sustainable Agriculture • Integrated pest management (IPM) • Crops and pests are evaluated as parts of a larger ecosystem • Comprehensive plan including: cultivation, biological controls, and chemical tools applied in a coordinated way
12-6 How Can We Produce Food More Sustainably? • Concept 12-6A Sustainable food production will require reducing topsoil erosion, eliminating overgrazing and overfishing, irrigating more efficiently, using integrated pest management, promoting agrobiodiversity, and providing government subsidies for more sustainable farming, fishing, and aquaculture. • Concept 12-6B Producing enough food to feed the rapidly growing human population will require growing crops in a mix of monocultures and polycultures and decreasing the enormous environmental impacts of industrialized food production.
Soil Conservation Methods • There are many different soil conservation techniques that can be employed to reduce soil erosion: Contour planting Terracing
Soil Conservation Methods Alley cropping Strip cropping Windbreaks No-till or minimum tillage
Fertilizers can help restore soil nutrients, but runoff of inorganic fertilizers can cause water pollution. Organic fertilizers – From plant and animal materials Animal manure Green manure – freshly cut vegetation plowed into soil Compost – broken-down organic matter Commercial inorganic fertilizers Made from minerals Active ingredients contain nitrogen (N), phosphorous (P), and potassium (K) and other trace nutrients Restore Soil Fertility
Three main ways to reduce hunger and malnutrition and the harmful effects of agriculture: Slow population growth Sharply reduce poverty Develop and phase in systems of more sustainable, low input agriculture over the next few decades Shift to More Sustainable Agriculture