Food and Agriculture Section 1 Food and Agriculture

Food and Agriculture Section 1 Food and Agriculture Chapter 15

Food and Agriculture Bellringer Section 1

Food and Agriculture Section 1 15. 1 FEEDING THE WORLD

Food and Agriculture Section 1: Feeding the World Preview • • • Feeding the World • Humans and Nutrition • • Sources of Nutrition Diets Around the World • The Ecology of Food • Food Efficiency Old and New Foods World Food Problems Unequal Distribution Droughts and Famines The Green Revolution

Food and Agriculture Section 1 Objectives 1. Identify the major causes of malnutrition. 2. Compare the environmental costs of producing different types of food. 3. Explain how food distribution problems and drought can lead to famine. 4. Explain the importance of the green revolution

Food and Agriculture Section 1 Famine • the widespread malnutrition and starvation in an area • due to a shortage of food, usually caused by a catastrophic event.

Food and Agriculture Section 1 Modern agriculture practices – provide most of the world’s population with enough food to survive. – However, some of these practices can cause environmental damage that eventually makes growing food crops more difficult.

Food and Agriculture Humans and Nutrition • The human body uses food – as a source of energy and – as a source of materials for • building and • maintaining body tissues. Section 1

Food and Agriculture Section 1 Calories • The amount of energy that is available in food is • One Calorie is equal to – 1, 000 calories or – one kilocalorie.

Food and Agriculture Section 1 The three major nutrients needed 1. carbohydrates, 2. proteins, and 3. Lipids (fats , steroids) • In addition – smaller amounts of vitamins and minerals to remain healthy.

Humans and Nutrition (copy to notes)

Food and Agriculture Section 1 Malnutrition • A disorder of nutrition – results when a person does not consume enough of each of the nutrients that are needed by the human body. • Many forms of malnutrition depending on the diet • Example: Need 8 essential amino acids from proteins. • This is easily done if a variety of foods is eaten. • However, if the only sources of food is corn and rice, which contain protein, but lacks one of the essential amino acids. • Amino acid deficiency can result

Food and Agriculture Section 1 Sources of Nutrition • Diet – the type and amount of food that a person eats. • A healthy diet – maintains a balance of the right amounts of nutrients, minerals, and vitamins.

Food and Agriculture Section 1 Food • Grains – produced in the greatest amounts worldwide, – plants of the grass family whose seeds are rich in carbohydrates. • Besides eating grains, most people eat – fruits, vegetables, and smaller amounts of meats, nuts, and other foods that are rich in fats and proteins.

Food and Agriculture Sources of Nutrition Section 1

Food and Agriculture Section 1 Diets Around the World • People worldwide generally – consume the same major nutrients and – eat the same basic kinds of food. • But, diets vary by region. • People in more developed countries – tend to eat more food and – a larger proportion of proteins and fats than people in less developed countries.

Food and Agriculture Diets Around the World Section 1

Food and Agriculture Section 1 The Ecology of Food • As the human population grows, – farmland replaces forests and grasslands. – Feeding everyone while maintaining natural ecosystems becomes increasingly difficult. • Different kinds of agriculture have – different environmental impacts and – different levels of efficiency.

Food and Agriculture Section 1 Food Efficiency • The efficiency of a given type of agriculture – a measure of the quantity of food produced on a given area of land with limited inputs of energy and resources. • An ideal food crop is – one that efficiently produces a large amount of food – with little negative impact on the environment.

Food and Agriculture Section 1 Food Efficiency • On average, – more energy, water, and land are used to produced a Calorie of food from animals than to produce a Calorie of food from plants. • Animals that are raised for human use – are usually fed plant matter, – but because less energy is available at each level on a food chain, – only about 10 percent of the energy from the plants gets stored in the animals.

Food and Agriculture Section 1 Food Efficiency Thus, a given area of land can usually produce more food for humans when it is used to grow plants than when it is used to raise animals.

Food and Agriculture Section 1 • The efficiency of raising plants for food is one reason why diets around the world are largely based on plants. • However, meat from animals generally provides more nutrients per gram than most food from plants.

Food and Agriculture Section 1 Old and New Foods • Researchers hope to improve the efficiency of food production by studying plants and other organisms that have high yield.

Food and Agriculture Section 1 Yield • is the amount of crops produced per unit area. • Researchers are interested in – organisms that • can thrive in various climates and • do not require large amounts of fertilizer, pesticides, or fresh water. – Some organisms have been a source of food for centuries, while other sources are just being discovered.

Food and Agriculture Section 1 World Food Problems • Malnourishment occurs because – people simply do not get enough food. • More food is needed each year to feed the world’s growing population. • World food production – has been increasing for decades, – but now food production is not increasing as fast as the human population is increasing.

Food and Agriculture World Food Problems Section 1

Food and Agriculture Section 1 Unequal Distribution • If all the food in the world today were divided equally among the human population, – no one would have quite enough food for good health. • But food is not divided equally, – malnutrition is largely the result of poverty. – Even in the US, many of the poor suffer • Wars and political strife – can also lead to malnutrition because they interrupt transportation systems.

Food and Agriculture Section 1 Droughts and Famines • A drought – is a prolonged period during which rainfall is below average, and – crops grown without irrigation may produce low yields or fail entirely. – Is more likely to cause famine in places where most food is grown locally.

Food and Agriculture Section 1 Droughts and Famines • If a drought occurs, • there may be no seed to plant crops the following year. • The effects of a drought can continue for years.

Food and Agriculture Section 1 • People in a given area – can usually survive one crop failure. – They may have saved enough food from previous seasons, or they may have systems for importing food from elsewhere.

Food and Agriculture Section 1 • But several years of drought – cause severe problems for any area of the world. – For example, • after a long drought, • the soil may be less able to support the production of food crops.

Food and Agriculture Section 1 The Green Revolution • Worldwide, between 1950 and 1970, – increases in crop yields resulted from 1. the use of new crop varieties and 2. the application of modern agriculture techniques. • Since the 1950 s, the green revolution – has changed the lives of millions of people. – However, also had some negative effects.

Food and Agriculture Section 1 For example, • Most new varieties of grain – produce large yields only if they receive large amounts of water, fertilizer, and pesticides. – In addition, the machinery, irrigation, and chemicals required by new crop varieties can degrade the soil if they are not used properly.

Food and Agriculture Section 1 • As a result of the overuse of fertilizers & pesticides, – yields from green revolution crops are falling. – The grain production in the U. S. has decreased since 1990, • partly because the amount of water used for irrigation has decreased.

Food and Agriculture Section 1 • In addition, The Green Revolution – a negative impact on subsistence farmers, or farmers who grow only enough food for local use. – Before the green revolution, • subsistence farmers worked most of the world’s farms. • But they could not afford the equipment, water, and chemicals needed to grow new crop varieties.

Math Practice Known Unknown Solution

Quick Check 15. 1

Food and Agriculture Bellringer Section 1

Food and Agriculture Section 2: Crops and Soil Preview • • Agriculture: Traditional/Modern Fertile Soil: The Living Earth Soil Erosion: A Global Problem Land Degradation Soil Conservation Enriching the Soil Salinization Section 1

Food and Agriculture Section 1 Objectives 1. Distinguish between traditional and modern agricultural techniques. 2. Describe fertile soil. 3. Describe the need for soil conservation.

Food and Agriculture Crops and Soil Section 1

Food and Agriculture Arable land • is farmland • limited area of arable land. • Dilemma – As the human population increases, – the amount of arable land person decreases. Section 1

Food and Agriculture Section 1 Agriculture: Traditional • The basic processes of farming include plowing, fertilization, irrigation, and pest control. – Plows helps • mixing soil nutrients, • loosening soil particles, and • uprooting weeds. – Organic fertilizers, such as manure, – Fields are irrigated by ditches.

Food and Agriculture Section 1 Agriculture: Modern • The basic processes of farming are now carried out using modern agricultural methods. – powered by fossil fuels – Synthetic chemical fertilizers have replaced manure and plant wastes • A variety of overhead sprinklers and drip systems may be used for irrigation. • Synthetic chemicals are used to kill pests.

Food and Agriculture Fertile Soil: – Supports the growth of healthy plants Section 1

Food and Agriculture Section 1 6 Basic Layers 1. 2. 3. 4. 5. 6. Surface liter Topsoil Zone of leaching Subsoil Rock particles Bedrock, which is the solid rock from which most soil originally forms.

Food and Agriculture Fertile Soil: The Living Earth Section 1

Food and Agriculture Section 1 Topsoil • surface layer of the soil, • usually richer in organic matter • composed of – living organisms, – rock particles, – water, – air, and – organic matter, such as dead or decomposing organisms.

Food and Agriculture Section 1 Soil • forms when rock is broken down into smaller and smaller fragments by – wind, – water, and – chemical weathering. • happens when the minerals in rock react chemically with substances to form new materials. • Temperature changes & moisture can cause rock to crack and break apart. • a few centimeters of soil can take hundreds or even thousands of years to form

Food and Agriculture Section 1 Other processes affected topsoil • the rock particles supply mineral nutrients • Fungi and bacteria decompose dead plants as well as organic debris nutrients • Earthworms, insects, and other small animals help by – breaking up the soil and – allowing air and water into it.

Food and Agriculture Section 1

Food and Agriculture Section 1 Soil Erosion: A Global Problem • a process in which materials of the Earth’s surface are and transported from one – Loosened, place to another by a natural – dissolved, or agent, such as wind, water, ice, or gravity. – worn away • In the U. S. , – About half of the original topsoil has been lost to erosion in the past 200 years. – Almost all farming methods increase the rate of soil erosion.

Food and Agriculture Soil Erosion: A Global Problem Section 1

Food and Agriculture Section 1 Land Degradation • Happens when human activity or natural processes damage the land – it can no longer support the local ecosystem. – In areas with dry climates, desertification can occur. • Desertification – A process by which human activities or climatic changes make arid or semiarid areas more desertlike. – is causing some of our arable land to disappear.

Food and Agriculture Section 1 For example of Land Degradation • In the past, people who – lived in the drier part of the Sahel region in Africa grazed animals, – Lived in the wetter part planted crops. • .

Food and Agriculture Section 1 For example of Land Degradation • The grazing animals – were moved from place to find fresh grass. • The cropland – was planted for only a few years, and – then allowed to lie fallow, or to remain unplanted, for several years. • These methods allowed the land to adequately support the people in the Sahel.

Food and Agriculture Section 1 But the population in the region has grown • The land is being farmed, grazed, and deforested faster than it can regenerate. – Crops • are planted too frequently and • fallow periods are being shortened or eliminated completely. As a result, the soil is losing fertility and productivity.

Food and Agriculture Section 1 But the population in the region has grown • Because of overgrazing, – the land has fewer plants to hold the topsoil in place. – large areas • desert and • can no longer produce food.

Food and Agriculture Section 1 Many ways to Conserve Soil • Soil usually erodes downhill, – many techniques are designed to prevent downhill erosion.

Food and Agriculture Section 1 Many ways to Conserve Soil • For example, – soil-retaining terraces can be build across a hillside. – On gentler slopes, contour plowing, which consists of plowing across the slope of a hill instead of up and down the slope, can be used.

Food and Agriculture Section 1 Soil Conservation • An even more effective method of plowing is leaving strips of vegetation across the hillside instead of plowing the entire slope. • These strips catch soil and water that run down the hill.

Food and Agriculture Section 1 No-till Farming • a crop is harvested without turning the soil over, as in traditional farming. • Later, the seeds of the next crop are planted among the remains of the previous crop. • The remains of the first crop hold the soil in place while the new crop develops. • saves time and reduces soil erosion,

Food and Agriculture Section 1 No-till Farming • Disadvantages – not suited for all crops. – Not good for soil that is too densely packed

Food and Agriculture Section 1 Enriching the Soil • traditionally – Added organic matter would decompose, adding nutrients and improving the soil texture. • However, inorganic fertilizers containing 1. nitrogen, 2. phosphorous, & 3. potassium – Doubles food production • If erosion occurs in areas fertilized with inorganic materials, waterways may become polluted.

Food and Agriculture Section 1 Enriching the Soil • Over the past 50 years, the use of such inorganic fertilizers has increased rapidly.

Food and Agriculture Enriching the Soil • A modern method – uses both organic and inorganic materials – adds compost and chemical fertilizers to the soil. • Compost – a mixture of decomposing organic matter, such as manure and rotting plants, – used as fertilizer and soil conditioner. Section 1

Food and Agriculture Many cities and industries – compost yard and crop wastes. , – sell or give away, – saving costly land fill space. Section 1

Food and Agriculture Salinization • The accumulation of salts in the soil • Major problem in places that have – low rainfall and – naturally salty soil. • When water evaporates from irrigated land, salts are left behind. Section 1

Food and Agriculture Picture Salinization Section 1

Food and Agriculture Section 1 Salinization • can be slowed if irrigation canals are lined to prevent water from seeping into the soil, or • if the soil is watered heavily to wash out salts.

Quick Check 15. 2 a

Food and Agriculture Section 1 Section 2: Crops and Soil Preview, continued • Pest Control Pesticides Pesticide Resistance • Human Health • Concerns • Pollution and • Persistence • Biological Pest Control • • Integrated Pest Management Engineering a Better Crop Implications of Genetic Engineering Sustainable Agriculture

Food and Agriculture Section 1 Objectives 15. 2 a 1. Explain the benefits and environmental impacts of pesticide use. 2. Explain what is involved in integrated pest management. 3. Explain how genetic engineering is used in agriculture.

Food and Agriculture Section 1 Pest Control • Worldwide, – pests destroy about one-third of the world’s potential food harvest. • A pest - any organism – That occurs where it is not wanted or – That occurs in large enough numbers to cause economic damage. – Many types: plants, fungi, insects, & microorganisms.

Food and Agriculture Section 1 Pesticides • a poison used to destroy pests, such as – insects, insecticides – rodents, rodenticides – Weeds; herbicides. • Pesticides, however, can also harm beneficial plants and insects, wildlife, and even people.

Food and Agriculture Section 1 Pesticide Resistance • Over time, may make the pest problem worse. • May evolve resistance, • Fact: – More than 500 species of insects have developed resistance to pesticides since the 1940 s.

Food and Agriculture Section 1 Human Health Concerns • Pesticides – are designed to kill organisms, – may also be dangerous to humans. • Cancer rates among children – in areas where large amounts of pesticides are used on crops – are sometimes higher than the national average. • People who apply pesticides need to follow safety guidelines to protect themselves from contact with these chemicals.

Food and Agriculture Section 1 Pollution and Persistence • A persistent pesticide – does not break down easily or quickly in the environment into harmless chemicals – Will accumulate in the water and soil. – Increases possibility of harming people and other organisms. • Some pesticides have been banned in the United States for decades but can still be detected in the environment.

Food and Agriculture Section 1 Biological Pest Control • Every pest has – enemies in the wild, and – these enemies can sometimes be used to control pest populations. • Biological pest control – includes the use of • pathogens, • plant defenses, • chemicals from plants, • and the disrupting of insect breeding

Food and Agriculture Section 1 Integrated Pest Management • a modern method of controlling pests • The goal – not to eliminate pest populations – but to reduce pest damage to a level that causes minimal economic damage. • Such programs can include a mix of 1. farming methods, 2. biological pest control, and 3. chemical pest control.

Food and Agriculture Section 1 Integrated Pest Management 1. Biological methods – Natural predators, pathogens, and parasites of the pest may be introduced. 2. Cultivation controls, – such as vacuuming insects off the plants, 3. Small amounts of insecticides – Last resort, – These insecticides are changed over time to reduce the ability of pests to evolve resistance.

Food and Agriculture Section 1 Engineering a Better Crop • Genetic engineering – a technology in which the genome of a living cell is modified for medical or industrial use. – Used to transfer desirable traits, such as resistance to certain pests, from one organism to another. • Plants that result from genetic engineering are called genetically modified (GM) plants.

Food and Agriculture Engineering a Better Crop Section 1

Food and Agriculture Section 1 Implications of Genetic Engineering • In the United States, we now eat and use genetically engineered agricultural products everyday. • Many of these products, – have not been fully tested for their environmental impacts. – Some scientists warn that these products will cause problems in the future.

Food and Agriculture Section 1 Sustainable Agriculture • Farming that conserves natural resources and helps keep the land productive indefinitely • Involves – planting productive, – pest-resistant crop varieties that require little energy, – pesticides, – fertilizer, and – water.

Quick Check 15. 2

Food and Agriculture Section 3: Animals and Agriculture Preview • Bellringer • Objectives • Animals and Agriculture • Food from Water • Overharvesting • Aquaculture • Livestock Section 1

Food and Agriculture Section 3: Animals and Agriculture Preview • Ruminants • Poultry Section 1

Food and Agriculture Bellringer Section 1

Food and Agriculture Section 1 Objectives • Explain how overharvesting affects the supply of aquatic organisms used for food. • Describe the current role of aquaculture in providing seafood. • Describe the importance of livestock in providing food and other products.

Food and Agriculture Section 1 Animals and Agriculture • Food from animals has been the basis of life for some human populations for centuries. • Our ancestors obtained animal protein by hunting and fishing. Today, most people get animal protein from domesticated species. • Domesticated describes organisms that have been bred and managed for human use.

Food and Agriculture Section 1 Food from Water • Because fish are an important food source for humans, the harvesting of fish has become an important industry worldwide. • However, when too many fish are harvested over a long period of time, ecological systems can be damaged.

Food and Agriculture Food from Water The North Atlantic cod fishery has collapsed because too many fish were harvested over time. Section 1

Food and Agriculture Section 1 Overharvesting • Overharvesting is the catching or removing from a population more organisms than the population can replace. • Many governments are now trying to stop overharvesting. They have created no-fishing zones, so that fish populations can recover.

Food and Agriculture Section 1 Aquaculture • Aquaculture is the raising of aquatic plants and animals for human use or consumption. • Fish and other aquatic organisms provide up to 20 percent of the animal protein consumed worldwide. • Aquaculture may be one solution to the overharvesting of fish and other organisms in the world’s oceans.

Food and Agriculture Section 1 Aquaculture • Aquaculture is not a new idea. • This practice probably began in China about 4, 000 years ago. • Today, China leads the world in using aquaculture to produce freshwater fish.

Food and Agriculture Section 1 Aquaculture • There a number of different methods of aquaculture. Among these are • Fish farming • Fish ranching • Fish farms generally consist of many individual ponds that each contain fish at a specific stage of development. Fish grow to maturity in the ponds and are then harvested. • Fish ranches raise fish to a certain age, release them to the ocean, and then harvest the adults when they return to their birthplace to breed.

Food and Agriculture Section 1 Aquaculture • As with other methods of food production, however, aquaculture can cause environmental damage if not managed properly. • Aquatic organisms can produce a large amount of waste, which can be a source of pollution. • Because aquaculture requires so much water, the process can deplete local water supplies. • Despite these problems, aquaculture will continue to be an important source of protein for the human diet.

Food and Agriculture Section 1 Livestock • Livestock is the term given to domesticated animals that are raised to be used on a farm or ranch or to be sold for profit. • Populations of livestock have changed dramatically in the last 40 years. • Large livestock operations produce most of the meat that is consumed in developed countries.

Food and Agriculture Livestock Section 1

Food and Agriculture Section 1 Livestock • In developing countries, livestock not only provide leather, wool, eggs, and meat, but also serve other functions. • Some livestock are used as draft animals to pull carts and plows. • Other livestock provide manure as the main source of plant fertilizer or as a fuel for cooking.

Food and Agriculture Section 1 Ruminants • Ruminants are cud-chewing mammals that have a three- or four-chambered stomach. • Cattle, sheep, and goats are examples of ruminants. • Cud is the food that these animals regurgitate from the first chamber of their stomachs and chew again to aid digestion. • When we eat the meat of ruminants, we are using them to convert plant material, such as grass stems and woody shrubs, into food that we can digest—such as beef.

Food and Agriculture Section 1 Ruminants • Humans have created hundreds of breeds of cattle that are suited to life in different climates. • Worldwide meat production person has increased significantly since 1950.

Food and Agriculture Section 1 Poultry • Since 1961, the population of chickens worldwide has increased to a greater percentage than the population of any other livestock. • Chickens are a type of poultry, domesticated birds raised for meat and eggs. • In more-developed countries, chickens and turkeys are usually raised in factory farms.

Food and Agriculture Graphic Organizer Section 1

Quick Check 15. 3