Soil and Agriculture 373

LESS

ON 4Food Production

•   Explain why the world needs to grow more food and to grow it sustainably.

•   Discuss genetically modified food.•   Describe the advantages and disadvantages of industrial food production.

•   Discuss sustainable agriculture.

Reading Strategy Before reading, create a three-column KWL chart. In the first column, write what you know about global food production. In the second column, write what you want to know. After you read the lesson, write what you learned in the third column. 

Vocabulary arable land, food security, malnutrition,  genetic engineering, genetically modified (GM) organism, biotechnology, feedlot, aquaculture, seed bank,  sustainable agriculture, organic agriculture

Guiding Question: How can we produce enough food for a rapidly growing population while sustaining our ability to produce it?

Each yEar, Earth gains about 75 million people and loses 5 million to 7 million hectares (12 million to 17 million acres) of productive crop-land. We can expect a world population of 9 billion by 2050. In order to feed the growing human population, we will likely need to increase agri-cultural production. We cannot keep expanding agriculture into new areas, because arable land, or land suitable for farming, is running out. Especially in drier regions, degraded soil has made raising crops and livestock more difficult. We must find ways to increase food production in areas that are already being used for agriculture and to do so in ways that maintain the health of our soils and ecosystems. This could involve approaches as diverse as the use of genetically modified crops and organic farming.

Food Security Because hunger continues and the population is growing, we

need to find a way to increase food production sustainably.

Despite increases in global food production, there are still hundreds of millions of hungry people. Feeding them will require that we continue improvements in food production and distribution while protecting our soil and ecosystems.

Food Production Since 1961, despite the loss of arable land, our ability to produce food has grown faster than the human population. We have increased food production by devoting more fossil fuel energy to agriculture; by planting and harvesting more frequently; by increasing the use of irrigation, fertilizers, and pesticides; by increasing the amount of cultivated land; and by developing more productive crop and livestock varieties. But the world’s soils are in decline, and nearly all the planet’s arable land is already being farmed. Just because agricultural production has outpaced population growth so far, there is no guarantee that it will continue to do so.

FOCUS Watch the ABC News video Fish Farms of the Future. Use the video to launch a discussion on the importance of balancing food production and sustaining the ecosystems in which the food is produced.

12.4 LESSON PLAN PREVIEWDifferentiated Instruction Struggling students use a graph to better understand trends in global food production.Inquiry Students  investigate traditional and industrial agri-culture.Real World Students research locally supported agriculture in their own communities.

12.4 RESOURCESBellringer Video, Fish Farms of the Future • Graph It, Animal Food Prod-ucts and Feed Input • Lesson 12.4 Worksheets • Lesson 12.4 Assessment • Chapter 12 Overview Presentation

Data from U.N. Food and Agriculture Organization.

Global Agricultural Food Production

4.0

3.0

3.5

4.5

2.0

2.5

1.5

1.01960 1970 1980 1990 2000

Gro

wth

rel

ativ

e to

196

1 le

vels

(pop

ula

tion

by

nu

mb

er o

f p

eop

le;

foo

d p

rod

uct

ion

by

wei

gh

t)Year

World populationVegetablesFruits

Other food crops

GrainsRoots and tubers

374 Lesson 4

And despite the rise in food production (Figure 20), 1 billion people are still hungry. So agricultural scientists and policymakers are aggres-sively pursuing the goal of food security, the guarantee of an adequate and reliable food supply for all people at all times. Making the food sup-ply secure depends on maintaining healthy soil and water, protecting the biodiversity of food sources, and ensuring the safe distribution of food.

Undernourishment and Malnutrition Most people who are undernourished, receiving less than 90 percent of their daily caloric needs, live in the developing world. For most people who are undernour-ished, the reasons are economic. Hunger is a problem even in the United States. In 2007, the Department of Agriculture classified 36 million Americans as “food insecure,” or lacking the income required to obtain sufficient food at all times.

Just as the quantity of food a person eats is important for health, so is the quality of food. Malnutrition, a shortage of nutrients the body needs, occurs when a person fails to obtain a healthy variety or quantity of nutri-ents. Malnutrition can lead to disease. When people eat too little protein, a disease called kwashiorkor results. Kwashiorkor causes bloating of the abdo-men, poor hair quality, skin problems, mental disability, lowered immunity, developmental delays in children, and anemia (Figure 21). Protein defi-ciency and a lack of calories can lead to marasmus, which causes wasting of the muscles and many other physical and mental problems. It is most prevalent among children in developing nations.

ReadingCheckpoint

What are three essential steps to global food security?

Figure 20 rising Food Production Global food production rose by more than two and a half times in the last 50 years, even faster than the world population. Production of all types of foods, particularly vegetables, has increased since 1961.

Figure 21 Malnutrition Millions of people suffer from hunger and the diseases it can lead to. This woman has kwashiorkor.

ANSWERS

reading Checkpoint Maintaining healthy soil and water, protecting the biodiversity of food sources, and ensuring safe food distribution

How can we balance our growing demand for food with our need to protect the environment?Interpretation Ask students to think about the following question: How are the food production methods used by one generation related to the nutrition of future generations? To develop their responses, students will need to apply what they learned about soil degradation, pollution, and desertification in Lesson 2 to the information in Lesson 4.

BIG QUESTION

Soil and Agriculture 375

Genetically Modified Organisms Genetically modified food is a promising way to increase food

production, but there needs to be more research into potential risks.

Industrial agriculture has enabled us to feed more people, but our con-tinuing population growth demands still more innovation. Some poten-tial solutions arose in the 1980s. For the first time, advances in genetics enabled scientists to directly alter the genes of organisms, including crop plants and livestock. This “gene revolution” could improve world nutrition and the efficiency of agriculture while lessening impacts on ecosystems. But because it is new, it may also pose unexpected risks.

Genetic Modification Any process in which scientists directly manipulate an organism’s DNA is called genetic engineering. Organisms that have undergone genetic engineering are often called genetically modified (GM) organisms. GM organisms are engineered using a tech-nique called recombinant DNA technology. Recombinant DNA is DNA taken from multiple organisms and pieced together, or recombined. In this process, scientists place genes that code for desired traits into the genomes of organisms lacking those traits. Rapid growth, pest resis-tance, and frost tolerance are commonly engineered traits in crop plants. Animals can also be genetically modified. For example, the goats in Figure 22 have been engineered to give milk that can be processed into a drug that treats people whose blood clots abnormally.

The creation of genetically modified organisms is one aspect of biotechnology, the use of genetic engineering to introduce new genes into organisms to produce more valuable products. Biotechnology has helped us develop medicines, clean up pollution, understand the causes of diseases, dissolve life-threatening blood clots, and improve crops and livestock.

ReadingCheckpoint

In your own words, define genetically modified organism.

FiGure 22 Genetically Modified Organisms These goats look perfectly normal. But their milk can produce a drug that treats people with abnormal blood clotting. (Because the substances are produced only in the goats’ mammary glands, the goats are not harmed.)

ANSWERS

reading Checkpoint Sample answer: A genetically modified organism is one whose DNA has undergone genetic engineering using recombinant DNA technology.

GM Crops by Nation

Data is for 2008, from the International Service for the Acquisition of Agri-Biotech Applications (ISAAA). 2009.

Argentina(16.8%)

China (3.0%)

India (6.1%)

Canada (6.1%)

Brazil (12.6%)

19 other nations (5.4%)

United States(50.0%)

376 Lesson 4

GM Crops Are Everywhere Many GM crops today are engineered to resist herbicides, so that farmers can kill weeds without worrying about killing their crops. Other crops are engineered to resist insect attack (often with the bacterium Bt, which you learned about in Lesson 3). Some are modified to resist both. Plants that are resistant to both herbicides and pests make it more efficient, and in some cases more economical, for large-scale commercial farmers to do their jobs. As a result, sales of GM seeds to these farmers in the United States and other developed nations have risen quickly.

The United States alone grows about half of the global total of GM crops, as Figure 23 shows. Today 85 percent of the U.S. corn harvest and more than 90 percent of U.S. soybeans, cotton, and canola crops are genetically modified strains. In the United States, 41 percent of corn and cotton crops are engineered for more than one trait. Worldwide, 70 per-cent of soybean crops are genetically modified, as are 25 percent of corn crops, 20 percent of canola crops, and nearly 50 percent of cotton crops.

Potential Risks As GM crops were adopted, as research proceeded, and as biotechnology expanded, many citizens, scientists, and policy-makers became concerned. Some feared the new foods might be danger-ous for people to eat. Others worried that pests would evolve resistance to the pest-resistant crops and become “superpests.” Still others were concerned that GM genes might “escape,” pollinating non-GM plants and harming those organisms or others.

That last concern is supported by evidence. A GM grass plant not yet approved by the USDA pollinated wild grass 21 kilometers (13 miles) away from its test growing site in Oregon. Because of this and similar events, such as the discovery of transgenes in Oaxaca, most scientists think GM genes will inevitably make their way from GM crops into wild plants. The consequences (or lack thereof) of this potential event are still being hotly debated, however. Because GM technology is new and chang-ing, scientists are still learning about it. Millions of people eat GM foods every day without obvious signs of harm, and evidence for negative envi-ronmental effects is limited so far. Nevertheless, more research is needed before we can dismiss all concerns about GM foods.

Figure 23 gM Crops Are everywhere The United States devotes the most land area to GM crops.

What Doyou think?

What Doyou think?

Soil and Agriculture 377

Potential Benefits Supporters of GM crops maintain that no ill health effects on people have been demonstrated and that GM crops are, in fact, beneficial for people and the environment. For example, growing insect-resistant Bt crops reduces the use of chemical insecticides, because farmers use fewer chemicals if their crops do not need them.

Researchers and biotechnology industry supporters also claim other environmental benefits from GM crops. They say these crops reduce car-bon emissions for two reasons: (1) if crops need fewer pesticide applica-tions, then the equipment used to apply pesticides uses less fuel; and (2) if herbicide-resistant crops encourage the adoption of no-till farming, then more carbon (in remnants of plants) remains in the soil and is not released to the atmosphere. One GM crop research agency estimated that in 2007, GM crops prevented carbon emissions equivalent to those of 6.3 million cars.

The Promise of GM Foods But so far, GM crops have not lived up to their promise of feeding the world’s hungry. Nearly all commercially available GM crops have either pesticidal properties (for example, Bt) or herbicide tolerance (Figure 24). These traits help primarily large-scale, commercial farmers in developed nations. Crops with GM traits that might benefit poor small-scale farmers in developing nations—increased nutrients, drought tolerance, and salinity tolerance—have not been widely developed. This may be because corporations have little economic incentive to develop such crops—farmers in developing nations cannot afford to buy expensive GM seed every year. Whereas the green revolu-tion was a largely public venture, the “gene revolution” seems to be largely driven by financial concerns of private corporations.

But environmental activists, policymakers, scientists, and big corpora-tions all agree that lack of food security is a problem and that agriculture should be made more environmentally friendly. They only disagree on appropriate responses to those challenges and the risks that each response would present. Clearly, the future of GM foods will depend on a great diversity of human concerns.

ReadingCheckpoint

Why are today’s GM crops unlikely to help feed poor people in developing nations?

Some people think GM products in the United States should be labeled. Given that 70 percent of processed food now contains GM ingredients, labeling would be more expensive for the food companies, a cost that might be passed on to the consumer. Do you want GM food to be labeled in the United States? Explain your answer.

Figure 24 Herbicide-resistant Crops This field of herbicide-resistant soybeans is being sprayed with an herbicide to kill weeds.

ANSWERS

What Do You Think? Opinions will vary but should be supported with facts.reading Checkpoint Today’s GM crops have traits designed to help commercial farmers in developed nations, not to provide the increased nutrients, drought tolerance, or salinity tolerance that would aid food production in developing nations.

Global Meat and Seafood Consumption

30

40

20

Wor

ld m

eat a

nd s

eafo

od

prod

ucti

on (k

g pe

r pe

rson

per

yea

r)

101960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Year

Meat

Seafood

Data from U.N. Food and Agriculture Organization.

378 Lesson 4

Industrial Food Production Feedlots, aquaculture, and other methods of industrial food produc-

tion are efficient, but they have disadvantages.

Plant foods make up a large portion of the human diet, but most of us also eat animal products such as meat, fish, milk, and eggs. Raising plants and animals for food affects the environment no matter how it is done. And the larger the scale of the food production, the larger the impact. Feedlots, aquaculture, and crop monocultures are typical methods of industrial food production—the large-scale food production by large corporations. All of these methods have positive and negative environmental impacts.

Feedlots Worldwide, the number of animals raised for food rose from 7.2 billion to 24.3 billion between 1961 and 2007. Since 1950, global meat production has increased by a factor of five, and global meat and seafood consumption per person has nearly doubled since 1960, as you can see in the graph in Figure 25.

This growth is both a cause and an effect of industrial agriculture. In traditional agriculture, livestock were kept by farming families near their homes or were grazed on open grasslands by ranchers or herders. These traditions have survived, but industrial agriculture offers a new method. Feedlots, also known as concentrated animal feeding operations or factory farms, are basically huge warehouses or pens designed to deliver energy-rich food to livestock or poultry. Today, more than half of the world’s pork and poultry comes from feedlots, as does much of its beef, including most U.S. beef.

▶ Advantages Feedlot operations allow for a greater, more efficient production of food and are necessary for a nation with a high level of meat consumption like the United States. Feedlots also have a clear benefit for the environment—cattle and other grazers in feedlots do not degrade soil through overgrazing. Imagine the environmen-tal effects of grazing 10 million cattle across the United States!

Feedlots also reduce the need for chemical fertilizers. One dairy cow can produce 20,400 kilograms (9250 pounds) of waste in a year. Some feedlots hold 100,000 cattle. Where does all that manure go? Feedlot manure is often applied to farm fields as fertilizer.

Figure 25 global Meat and Seafood Consumption Per capita consumption of meat has risen steadily worldwide. Feedlots (background), which are very efficient, and aquaculture may be required in order to meet the demand.

Data from U.N. Food and Agriculture Organization. 2008. The state of world �sheries and aquaculture.

Global Aquaculture Production by Group

Other aquatic animals2.6%

Crustaceans7.4%

Fish48%

Aquaticplants22.3%

Mollusks19.7%

Aquaculture

✔ On small scale, ensures local people a reliable protein source

✔ Can be sustainable— for example, �sh scraps make excellent fertilizer

✔ Reduces harvesting of declining wild aquatic animals

✔ Reduces by-catch, the unintended death of nontarget animals

✔ Uses less fossil fuel than �shing vessels do

✔ Provides a safer work environment than commercial �shing does

✘ Diseases spread easily through dense populations, reducing production and pro�t

✘ Produces enormous amounts of waste that may pollute water outside of farm

✘ Escaped organisms may spread disease to wild animals

✘ Escaped organisms (such as large GM salmon) may outcompete wild animals and threaten wild populations

Bene�tsCosts

Soil and Agriculture 379

▶ Disadvantages Improper management of feedlot manure, however, can lead to illnesses in feedlot animals and in humans and other animals, often through contamination of bodies of water. Also, because feedlot animals often live in crowded, dirty conditions, the animals need to be given heavy doses of antibiotics to control disease. These antibiotics may make their way into the people who eat animal products. The antibiotics may also leach into groundwater or run off into surface water, affecting ecosystems. In addition, heavy use of antibiotics makes it more likely that bacteria will evolve resistance to them, making the antibiotics less effec-tive. Cattle are also often given steroids to promote growth, and these can also pass into surface water or groundwater through manure.

Some people also question the treatment of animals in feedlots, where they are often packed so densely that they cannot move around or interact normally with other animals. Some animals show signs of stress, such as chickens that peck themselves or others and pigs that chew their neighbors’ tails.

Although feedlots have many disadvantages, they are probably a nec-essary evil. And negative impacts can be lessened if a feedlot is properly managed. To help ensure proper management, the Environmental Protec-tion Agency and state agencies regulate U.S. feedlots.

Aquaculture Not all of our food is grown or raised on land, of course. People also eat aquatic organisms. Fish populations are decreasing throughout the world’s oceans as increased demand and new technologies have allowed us to overharvest many species. Aquaculture, or fish farm-ing, is the raising of aquatic organisms for food in a controlled environ-ment. It may be the only way to meet the increasing demand. Aquaculture is now the fastest-growing type of food production. We raise five times more food from it than we did 20 years ago. Aquaculture provides one third of the aquatic animals that are eaten by humans, and more than 220 species are farmed. Aquaculture has great benefits, and it can be practiced sustainably, but it also has risks (Figure 26).

Figure 26 Aquaculture Costs and Benefits Many different species of aquatic animals are raised for food (graph above). Like all methods of raising food, aquaculture has costs and benefits (left). For example, GM salmon can be 5 to 50 times larger than wild salmon of the same species (above) and may outcompete them if they were to meet in the wild.

Beef (245.0 m2)

Beef (750 kg)

Pork (175 kg)

Milk (250 kg)

Eggs (15 kg)

Pork (90.0 m2)

Milk (23.5 m2)

Eggs (22.0 m2)

Chicken(14.0 m2)

Chicken(50 kg)

(a) Land required to produce 1 kg of protein

(b) Water required to produce 1 kg of protein

Data from Smil, V. 2001. Feeding the world: A challenge for the twenty-�rst century. Cambridge, MA: MIT Press.

380 Lesson 4

Effects on Plant Diversity As you recall, the efficiency of industrial agriculture relies on monocultures. That means that a disease or pest that specializes in a specific plant could wipe out an entire crop. One concern many people have about GM crops is that GM genes might move by pol-lination into wild relatives of crop plants, outcompete them, and force them into extinction. If that were to happen, we could eventually be left with a monoculture in the wild as well as on the farms. Then an especially dangerous pest could destroy all our corn—GM, conventional, and wild. This would be devastating to the global food supply. But if we still had wild varieties that the pest had not evolved with, those varieties might be less susceptible to the pest. We could save our corn—and many lives.

▶ Losses We have already lost a great deal of genetic diversity in our crop plants. Since 1930, the number of Mexico’s native maize varieties, from which all of today’s corn varieties descend, has decreased by 70 percent. In the United States, we have lost most of our fruit and vegetable varieties—90 percent in less than a century.

A major cause of this loss of diversity is that market forces have discouraged diversity. For example, large food processing and distributing companies prefer items that are of similar size and shape and that are less likely to be damaged during long-distance shipping. For example, many large farms grow the same tomato vari-eties, often smaller ones with thicker skins, because it is easier to ship them. So next time you are disappointed in the taste of a tomato, check where it was grown. If it was grown more than a couple hundred kilometers away, it might have been grown for thick skin—not flavor!

▶ Preservation Protecting areas with high plant diversity is one way to preserve the genetic diversity of our crops. Another is to collect and store seeds from diverse crop varieties. This is what seed banks do. Seed banks are organizations that preserve seeds of diverse plants as a kind of insurance policy against a global crop collapse. Seed banks periodically grow plants from their seeds to harvest fresh seeds. The Royal Botanic Garden’s Millennium Seed Bank in England holds more than 1 billion seeds, including seeds from 10 percent of the world’s plants—more than 24,000 species. They aim to collect seeds from 25 percent of the world’s plants by 2020.

Energy Efficiency Our food choices are also energy choices. We have discussed the use of fossil fuels in industrial agriculture. But what we choose to eat also affects how efficiently we use the sun’s energy. Recall that every time energy moves from one trophic level to the next, as much as 90 percent of the energy is lost, mainly as heat.

Figure 27 Animal Food Products and resource use When we choose what to eat, we are also choosing how to use resources. The illustrations in this figure are sized according to the amount of land or water required to produce protein from the given animal source. Beef requires by far the most land and water.

Output(edible weight)

Feed input

20.0 kg

7.3 kg

4.5 kg

2.8 kg

1.1 kg

1 kg

Beef

Pork

Eggs

Chicken

Milk

1 kg

1 kg

1 kg

1 kg

Data from Smil, V. 2001. Feeding the world: A challenge for the twenty-�rst century. Cambridge, MA: MIT Press.

Soil and Agriculture 381

For example, if we feed grain to a cow and then eat beef from the cow, we have lost 90 percent of the energy in the grain to the cow’s metabo-lism. For this reason, the production of meat for food is extremely inef-ficient, as you can see in Figures 27 and 28.

Sustainable Agriculture Sustainable alternatives to industrial agriculture include

organic agriculture and locally supported agriculture.

Industrial agriculture can have many adverse environmental impacts, from the degradation of soils to reliance on fossil fuels to problems aris-ing from pesticide use, genetic modification, and feedlot and aquaculture operations. Although industrial agriculture helps relieve certain environ-mental pressures, it aggravates others. Industrial agriculture seems neces-sary to feed our planet’s almost 6.8 billion people, but we may be better off in the long run by practicing other methods as well.

Farmers and researchers have made great advances toward sustain-able agriculture in recent years. Sustainable agriculture is agriculture that does not deplete soil faster than it forms. It also does not reduce the amount or quality of soil, water, and genetic diversity essential to long-term crop and livestock production. Simply put, it is agriculture that can be practiced in the same way far into the future.

Figure 28 Animal Food Products and Feed input It requires much more feed to produce a kilogram of meat than it does to produce a kilogram of eggs or milk.

Animal Food Production and Food Policy

USDA Organic Criteria

• The land where they are grown must be free of prohibited substancesfor at least 3 years.

• They must not be genetically engineered.• They must not be treated with radiation (to kill bacteria).• The use of sewage sludge is prohibited.• They must be produced without fertilizer containing syntheticingredients, except those approved by the National Organic Standards Board.

• Use of most conventional pesticides is prohibited.• Use of organic seeds and other planting stock is preferred.• Pests, weeds, and diseases should be controlled without syntheticsubstances except those approved by the National Organic Standards Board.

• Mammals must be raised organically from thelast third of gestation; poultry, from the second day of life.

• Livestock must be fed 100% organic feed;vitamin and mineral supplements are allowed.

• Existing dairy herds must be fed 80% organicfeed for 9 months, followed by 3 months of 100% organic feed.

• Use of hormones or antibiotics is prohibited,although vaccines are permitted.

• Animals must have access to the outdoors.

For livestock to be considered organic…For crops to be considered organic…

Data from the National Organic Program. 2002. Organic production and handling standards. Washington, D.C.: U.S. Department of Agriculture.

382 Lesson 4

Organic Agriculture Sustainable agriculture that uses smaller amounts of pesticides, fertilizers, growth hormones, water, and fossil fuel energy than are currently used in industrial, high-input agriculture is often called low-input agriculture. Food-growing practices that use no synthetic fertilizers, insecticides, fungicides, or herbicides—but instead rely on biological approaches such as composting and biological pest control—are called organic agriculture.

Citizens, government officials, farmers, and the agricultural industry debated the meaning of the word organic in this context for many years. In 1990, Congress passed the Organic Food Production Act, establishing standards for organic products and facilitating the sale of organic food. As required by that law, the USDA in 2000 issued criteria by which it would certify crops and livestock as organic (Figure 29). These standards went into effect in 2001.

▶ Growth Organic foods once made up just a tiny proportion of food sales, but the market is increasing sharply. Although organic foods accounted for only about 3.5 percent of food purchases in the United States in 2008, that represents an increase of 200 percent since 1999—just nine years! Many consumers favor organic products because they are con-cerned that consuming produce grown with pesticides may pose health risks. Consumers also buy organic produce out of a desire to protect air, water, and land, and to protect nontarget organisms from pesticides and herbicides. And consumers likely have increased confidence that they are buying a truly organic product since the use of the “USDA Organic” seal began in 2001 (Figure 29).

Production is increasing along with demand. Although organic agriculture is practiced on less than 1 percent of farmed land worldwide, that area is increasing. In the United States and Canada, the land used for organic agriculture has been increasing 10–35 percent each year. Farmers in all 50 U.S. states and more than 130 nations now practice organic farm-ing commercially.

Figure 29 uSDA Organic Certification In 2000, the USDA compiled a list of criteria food must meet to be certified organic. The “USDA Organic” seal indicates the department’s certification.

ANSWERS

Lesson 4 Assessment1. Hunger still exists and the world

population is growing. The methods need to be sustainable, because we need to continue growing food.

2. A GM organism is one whose genetic material has been directly manipulated by scientists; ques-tions will vary, but should allude to possible environmental and health impacts.

3. Advantages: it produces a lot of food efficiently, and feedlots keep millions of cattle from overgraz-ing our grasslands; disadvantages: feedlots produce a lot of waste containing bacteria, steroids, and other drugs given to cattle, which can pass into water supplies; treat-ment of animals in feedlots may be questionable.

4. Opinions will vary but should be well reasoned and based on facts.

5. Reasons will vary but should allude to the fossil fuels used to ship food long distances and the economic benefits of supporting one’s own region.

Soil and Agriculture 383

41. Explain Why does the world need to grow more

food? Why do the methods need to be sustainable?2. Pose Questions What is a genetically modified

organism? What questions would you ask about a food made from genetically modified corn before eating it?

3. Review What are two advantages and two disad-vantages of industrial food production?

4. Form an Opinion Do you think organic foods are worth the extra cost? Explain.

5. Explore the BIGQUESTION A locavore is a person who eats mostly locally grown or raised food. Give three reasons why a person might become a locavore.

▶ Financial Considerations Financial obstacles unique to organic farming include the start-up costs of shifting to organic methods. But once it is established, organic farm-ing can yield just as much income as conventional farming. Organic farmers avoid the expense of buying chemical pes-ticides and herbicides, though some of their costs are higher than those of conventional farmers. And organic foods can sell for higher prices because of a smaller supply than demand.

While many shoppers will not buy organic produce if it is more expensive than conventional produce, many will. Because of the demand, most supermarket chains carry some organic products. In some supermarket chains, organic foods are the norm.

Locally Supported Agriculture In developed nations, increasing numbers of consumers are supporting local, small-scale agriculture. Farmers’ markets are multiplying as consumers rediscover the pleasures of fresh, locally grown produce (Figure 30). The average food product sold in a U.S. supermarket travels at least 2400 kilometers (1500 miles) between the farm and the shelf, and it is often chemically treated to preserve it during the long trip. In addition, there are few produce varieties in most supermarkets, and as you recall, those varieties are not necessarily grown for their flavor. In contrast, at farmers’ markets, consumers can buy a wide variety of local produce grown for taste, texture, and color rather than for durability. And buyers can boost their local economy by supporting local businesses.

Some consumers are also partnering with local farms in an arrangement called community-supported agriculture (CSA). In CSA, consumers pay farmers in advance for a weekly share of their produce yield during the growing season. Consumers get local, fresh, in-season produce, while local farmers get a guaranteed income to invest in their crops—an alternative to taking out loans and being at the mercy of the weather. As of 2007, hundreds of thousands of consumers and 12,500 farms were involved in CSA programs.

FiguRE 30 Locally grown Food Farmers’ markets, such as this one in Homestead, Florida, have become more widespread as consumers have rediscovered the benefits of buying fresh, locally grown produce.