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Chapter 12 Review Questions Food, soil and Pest Management Answer questions & fill in Review the Key Questions and Concepts for this chapter on p. 278. Define organic agriculture and compare its main components with those of conventional industrialized agriculture. Organic agriculture is a type of sustainable agriculture that differs from conventional industrial agriculture insofar as crops are grown without synthetic pesticides, synthetic inorganic pesticides and genetically modified seeds. Define food security and food insecurity. What is the root cause of food insecurity? Distinguish between chronic undernutrition (hunger) and chronic malnutrition and describe their harmful effects. What is a famine? Describe the effects of diet deficiencies in vitamin A, iron, and iodine. What is overnutrition, and what are its harmful effects? Food security means having enough food to meet basic nutritional needs. Food insecurity not getting enough to eat and—living with chronic hunger and poor nutrition.Most agricultural experts agree that the root cause of food insecurity is People who cannot grow or buy enough food to meet their basic energy needs suffer from chronic undernutrition, or hunger. Many suffer from Many of the world’s poor can afford only to live on a low-protein, high-carbohydrate, vegetarian diet consisting mainly of grains such as wheat, rice, or corn causing A famine is a severe food shortage that can result in mass starvation, deaths, and social disruption.Lack of vitamin A can cause children younger than age 6 to go _____________each year and double chances of dying within a year. Having too ________________________causes anemia which results in fatigue, makes infection more likely, and increases a woman’s chances of dying from hemorrhage in childbirth. Chronic lack of___________________________________________, which produces hormones that control the body’s rate of metabolism, and can cause stunted growth, mental retardation, and goiter—a swollen thyroid gland that can lead to deafness. Overnutrition occurs when food energy intake exceeds energy use and causes excess body fat. Too many calories, too little exercise, or both can cause overnutrition. People who are underfed and underweight and those who are overfed and overweight face similar health problems3.What three systems supply most of the world’s food? Define irrigation. Distinguish among industrialized agriculture (high-input agriculture), plantation agriculture, hydroponics, traditional subsistence agriculture, traditional intensive agriculture, polyculture, and slash- and- burn agriculture. What are the major advantages and disadvantages of raising food hydroponically in greenhouses? How does conventional agriculture violate the three principles of sustainability? Define soil and describe its formation and the major layers in mature soils. What is a green revolution? Describe industrialized food production in the United States. Croplands produce mostly grains, rangelands, pastures, and feedlots produce meat, and fisheries and aquaculture provide us with seafood. Irrigation means supply water to crops __________________. Industrialized agriculture, or high-input agriculture__________________Plantation agriculture is a form of industrialized agriculture used primarily in tropical developing countries. It involves growing cash crops such as bananas, soybeans (mostly to feed livestock), sugarcane (to produce sugar and ethanol fuel), coffee, palm oil (used as a cooking oil and to produce biodiesel fuel), and vegetables. Crops are grown on large monoculture plantations, mostly for export to developed countries. Producing such monoculture crops in the tropics increases yields but decreases ____________________Hydroponics involves growing plants by exposing their roots to a nutrient-rich water solution instead of soil, usually inside of a greenhouse.Traditional subsistence agriculture supplements energy from the sun (for photosynthesis) with the labor of humans and draft animals to produce enough crops for a farm family’s survival, with little left over to sell or store as a reserve for hard times.In traditional intensive agriculture, farmers increase their inputs of human and draft-animal labor, animal manure for fertilizer, and water to obtain higher crop yields. If the weather cooperates, they produce enough food to feed their families and have some left to sell for income. SMany traditional farmers grow several crops on the same plot simultaneously, a practice known as _____________________________ ______________________________ agriculture is a type of polyculture. This type of subsistence agriculture involves burning and clearing small plots in tropical forests, growing a variety of crops for a few years until the soil is depleted of nutrients, and then shifting to other plots.The advantages of ___________________________________ are that crops can be grown indoors under controlled conditions almost anywhere, yields and availability are increased because crops are grown year round, crops can be grown on rooftops, with artificial lighting, and on floating barges, thus requiring much less land, fertilizer and water use are reduced, and the need for pesticides is diminished. The disadvantages are the amount of capital required to start an operation, the fear of technical knowledge required, and the opposition of well-established corporations that produce farm supplies and chemicals. Modern industrialized agriculture violates the principles of sustainability because it relies heavily on nonrenewable fossil fuels, does not rely on a diversity of crops as a form of ecological insurance, and neglects the conservation and recycling of nutrients in topsoil.Soil is a complex mixture of . Soil formation begins when bedrock is slowly broken down into fragments and particles by physical, chemical, and biological processes, called ___________________________. Most soils that have developed over a long period of time, called ______________ contain distinct horizontal layers, or horizons. Most mature soils have at least _______________ of the possible horizons. The roots of most plants and the majority of a soil’s organic matter are concentrated in a soil’s two upper layers, the ___________horizon of leaf litter and the ___________ horizon of topsoil. Bacteria and other decomposer microorganisms break down some of the soil’s complex organic compounds. The result is a porous mixture of the partially decomposed bodies of dead plants and animals, called ______________), and inorganic materials such as clay, silt, and sand. The ____________________horizon (subsoil) and the _______________ horizon (parent material) contain most of a soil’s inorganic matter, mostly broken-down rock consisting of varying mixtures of sand, silt, clay, and gravel. Since 1950, about ___________________ of the increase in global food production has come from using high-input industrialized agriculture to increase yields in a process called __________________________. See Case Study: Industrialized Food Production in the United States.Distinguish between crossbreeding through artificial selection and genetic engineering. Describe the second gene revolution based on genetic engineering. Describe the growth of industrialized meat production. What is a fishery? What is aquaculture? Summarize the use of energy in industrialized food production. Why does it result in an energy loss? Traditional crossbreeding is a slow process, typically taking 15 years or more to produce a commercially valuable new crop variety, and it can combine traits only from species that are genetically similar. Genetic engineering involves altering an organism’s genetic material through adding, deleting, or changing segments of its DNA to produce desirable traits or to eliminate undesirable ones. It enables scientists to transfer genes between different species that would not interbreed in nature. The resulting organisms are called genetically modified organisms (GMOs).The second gene revolution involves altering an organism’s genetic material by adding, deleting, or changing segments of its DNA to produce desirable traits or to eliminate undesirable ones. It also allows for the transfer of genetic material between organisms that would not be able to interbreed in nature. Meat production produced through an energy intensive industrialized system in which animals are raised mostly in densely packed feedlots and confined animal feeding operations where they are fed grain or meal produced from fish. For example, large numbers of cattle are brought to feedlots where they are fattened up for about four months before slaughter. Between 1961 and 2007, world meat production increased more than fourfold and average meat consumption per person more than doubled.A fishery is a concentration of a particular aquatic species (usually fish or shellfish) suitable for commercial harvesting in a given ocean area or inland body of water. Aquaculture involves the raising of marine and freshwater fish in ponds and underwater cages instead of hunting and gathering them. Energy is used in food production to run farm machinery, irrigate crops, and produce pesticides (mostly from petrochemicals) and commercial inorganic fertilizers. Fossil fuels are also used to process and transport food.This results in a net energy loss because it takes about 10 units of nonrenewable fossil fuel energy to put 1 unit of food energy on the table.What are two major advantages of high-yield modern agriculture? What are the major harmful environmental impacts of agriculture? What is soil erosion and what are its two major harmful environmental effects? What is desertification and what are its harmful environmental effects? Distinguish between salinization and waterlogging of soil and describe their harmful environmental effects. What is the biggest problem resulting from excessive use of water for irrigation in agriculture?The major advantages of modern agriculture are that large amounts of food are produced per unit area and prices are low. See Figure 12- 10 Major harmful environmental effects of food production. Future food production may be limited by soil erosion and degradation, desertification, water and air pollution, climate change from greenhouse gas emissions, and loss of biodiversity. Soil erosion is the movement of soil components, especially surface litter and topsoil, from one place to another by the actions of wind and water. Soil erosion causes loss of soil ____________________through depletion of plant nutrients in topsoil, and water pollution in nearby surface waters. This can kill fish and shellfish and clog irrigation ditches, boat channels, reservoirs, and lakes. Additional water pollution occurs when the eroded sediment contains residues of pesticides. _____________________________occurs when the productive potential of soil falls by 10% or more because of a combination of prolonged drought and human activities that reduce or degrade topsoil. Desertification can caused drops in food production, water shortages and environmental _______________.Repeated annual applications of irrigation water in dry climates lead to the gradual accumulation of salts in the upper soil layers—a soil degradation process called _______________. It stunts crop growth, lowers crop yields, and can eventually kill plants and ruin the land. Irrigation can cause waterlogging, in which water accumulates underground and gradually raises the water table. Farmers often apply large amounts of irrigation water to leach salts deeper into the soil. Without adequate drainage, waterlogging occurs and saline water then surrounds the deep roots of plants, lowering their productivity and killing them after prolonged exposure. The biggest problem with excessive irrigation is that it contributes to the _____________________________________________________________________________________Summarize agriculture’s contribution to projected climate change. Explain how industrialized food production systems reduce biodiversity in areas where crops are growing. What is agrobiodiversity and how is it being affected by industrialized food production? Describe the advantages and disadvantages of using genetic engineering in food production. What factors can limit green revolutions? Compare the advantages and disadvantages of industrialized meat production. What is the connection between feeding livestock and the formation of ocean dead zones? Describe the use of energy in industrialized agriculture. Compare the advantages and disadvantages of aquaculture. Agricultural activities create a great deal of __________. They also account for more than ____________of the human-generated emissions of the greenhouse gases carbon dioxide, methane, and nitrous oxide, which are helping to warm the atmosphere_____________________________ is threatened when forests are cleared and grasslands are plowed up and replaced with croplands. ___________________________________ is the world’s genetic variety of animal and plant species used to provide food. Industrialized food production has led to a sharp decline in agrobiodiversity. Some estimate that the ? of all crop diversity has been lost since 1900.Projected advantages of genetically modified crops and foods See class notes on wallThere are several factors that have limited the success of the green revolutions to date and that may limit them in the future. Without huge inputs of fertilizer, pesticides, and water, most green revolution crop varieties produce yields that are no higher than those from traditional strains. These high inputs cost too much for most subsistence farmers in developing countries. Producing meat by using feedlots and other confined animal production facilities increases meat production, reduces overgrazing, and yields higher profits. However, such systems use large amounts of energy and water and produce huge amounts of animal waste that sometimes pollutes surface water and groundwater and saturates the air with their odor. Large amounts of manufactured inorganic fertilizers are used in the mid-western United States to produce corn for animal feed. Much of this fertilizer runs off cropland and eventually goes into the Mississippi River The added nitrate and phosphate nutrients overfertilize coastal waters in the Gulf of Mexico, where the river flows into the ocean, creating a “dead zone.”Advantages of aquaculture include: high efficiency, high yield in small volume of water, can reduce overharvesting of fisheries, low fuel use, and high profits. Disadvantages include: needs large inputs of land, feed, and water; large waste output; can destroy mangrove forests and estuaries; uses grain, fish meal, and fish oil to feed some species; and dense populations vulnerable to disease.Describe Rachel Carson’s contribution to environmental science. Describe the advantages and disadvantages of modern pesticides. Describe the use of laws and treaties to help protect us from the harmful effects of pesticides. List and briefly describe seven alternatives to conventional pesticides. Define integrated pest management (IPM) and discuss its advantages and disadvantages. See Individuals Matter: Rachel Carson. Advantages of conventional chemical pesticides include: save lives, increase food supplies, profitable, work fast, and safe if used properly. Disadvantages include: promote genetic resistance, kill natural pest enemies, pollute the environment, can harm wildlife and people, and are expensive for farmers. In the United States, three U.S. federal agencies, the EPA, the USDA, and the FDA, regulate the sale and use of pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act. The Food Quality Protection Act requires the EPA to reduce the allowed levels of pesticide residues in food by a factor of 10 when there is inadequate information on the potentially harmful effects on children. There is controversy over how well U.S. citizens are protected from the harmful effects of pesticides, with some scientists calling FIFRA the weakest and most poorly enforced U.S. environmental law. Alternatives to conventional pesticides include: 123Integrated Pest Management involves using a combination of ________________________________ tools and techniques to reduce crop damage to an economically tolerable level., When an economically damaging level of pests is reached, farmers first use biological methods (natural predators, parasites, and disease organisms) and cultivation controls (such as rotating crops, altering planting time, and using large machines to vacuum up harmful bugs). Insecticides are used only as a last resort and in the smallest amounts possible. IPM program can reduce pesticide use and pest control costs ________________________without reducing crop yields and food quality. IPM can also reduce inputs of fertilizer and irrigation water, and slow the development of genetic resistance, because pests are assaulted less often and with lower doses of pesticides. IPM is an important form of _____________________________________________________What are the two main approaches used by governments to influence food production? How have governments used subsidies to influence food production and what have been some of their effects? What are three other ways in which organizations are improving food security?Ways that governments influence food production include:___________________________________________. Use price controls to keep food prices artificially low. ___________________________________. Give farmers price supports, tax breaks, and other subsidies to keep them in business and to encourage them to increase food production. Governments give farmers price supports, tax breaks, and other financial support to keep them in business and to encourage them to increase food production. This can result in overproduction. Organizations are improving food security by working to reduce population growth, buying food from small farmers to increase food security, and issuing small loans to help people start businesses and buy land. What is soil conservation? Describe six ways to reduce soil erosion. Summarize the history of soil erosion and soil conservation in the United States. Distinguish among the uses of organic fertilizer, manufactured inorganic fertilizer, animal manure, green manure, and compost as ways to help restore topsoil fertility. Describe ways to prevent and clean up soil salinization. How can we reduce desertification? How can we make aquaculture more sustainable? Describe ways to produce meat more efficiently and sustainably. Summarize three important aspects of making a shift to more sustainable food production. Describe the advantages of organic farming and its role in shifting to more sustainable agriculture. What five strategies could help farmers and consumers shift to more sustainable agriculture? What are three important ways in which individual consumers can help to promote more sustainable agriculture?Soil conservation involves using a variety of ways to reduce soil erosion and restore soil fertility, mostly by keeping the soil ___________________________________________________. Soil conservation methods include:6. See Case Study. Soil erosion in the United States – Learning from the Past To restore soil nutrients, farmers can use organic fertilizer made from plant and animal wastes or commercial inorganic fertilizer produced from various mercial inorganic fertilizers contain nitrogen, phosphorus, and potassium. Inorganic fertilizer use has grown more than eleven fold since 1950. These fertilizers can run off the land and pollute nearby bodies of water and coastal estuaries where rivers empty into the sea. These fertilizers can replace depleted inorganic nutrients, but they do not replace organic matter. To completely restore nutrients to soil, both inorganic and organic fertilizers should be used.There are many different types of organic fertilizer. Animal manure is the dung and urine of cattle, horses, poultry, and other farm animals. It adds organic nitrogen and stimulates the growth of beneficial soil bacteria and fungi. Green manure consists of freshly cut or growing green vegetation that is plowed into the topsoil to increase the organic matter and humus available to the next crop. Compost is produced when microorganisms in soil break down organic matter such as leaves, crop residues, food wastes, paper, and wood in the presence of oxygen. Methods for preventing soil salinization include: reduce irrigation and switch to salt-tolerant crops (such as barley, cotton, and sugar beet). Clean-up includes: flush soil (expensive and wastes water), stop growing crops for 2–5 years, and install underground drainage systems (expensive).We can reduce desertification by _______________________________________________________. Ways to make aquaculture more sustainable and to reduce its harmful effects: Restrict locations of fish farms to reduce losses of mangrove forests and estuaries. Improve management of aquaculture __________________________________Reduce escape of aquaculture species into ____________________________. Raise some aquaculture species in deeply submerged cages to protect them from wave action and predators and to allow dilution of wastes into the ocean. Certify sustainable forms of aquaculture and label products accordingly. A more sustainable form of meat production and consumption involves shifting from less grain-efficient forms of animal protein, such as beef, pork, and carnivorous fish produced by aquaculture, to more grain-efficient forms, such as poultry and herbivorous farmed fish. Another approach is to find alternatives to growing grain to feed livestock. India’s dairy industry based mostly on feeding dairy cows roughage such as rice straw, wheat straw, corn stalks, and grass gathered from roadsides. Developing meat substitutes is an alternative. Three important aspects of shifting to more sustainable food production are that it would require less energy, would restore topsoil fertility and reduce erosion, and be more profitable for families while enhancing food security. In organic farming crops are grown with little or no use of synthetic pesticides, synthetic fertilizers, or genetically engineered seeds. Livestock are raised without use of genetic engineering, synthetic growth regulators, or feed additives. Fields must be free of chemicals for _________________________before crops grown there can be certified as organic. Since 1990, organic farming has been the fastest growing sector of the agricultural economy.Five strategies for shifting to a more sustainable agriculture include:government subsidies for environmentally harmful forms of industrialized agriculture with subsidies that encourage more sustainable agriculture.Mounting a massive program to educate consumers about the true costs of the food they buy.Individual consumers can:Use organic farming to grow some of their own food.Buy certified organic food.Eat locally grown food.What are the three big ideas of this chapter? Describe the relationship between industrialized agriculture and the three principles of sustainability. How can these principles be applied toward making a shift to more sustainable food production systems. The three big ideas are:More than ______________________ people have health problems because they do not get _______ to eat and 1.1 billion people face health problems from eating__________________________.Modern industrialized agriculture has a greater ______________________________________than any other human activity.More sustainable forms of food production will greatly reduce the harmful environmental impacts of current systems while increasing food security.Industrialized agriculture diminished ___________________________________________________These principles call for a more sustainable agricultural system that conserves biodiversity, cycles nutrients and is solar powered. Critical ThinkingThe following are examples of the material that should be contained in possible student answers to the end of chapter Critical Thinking questions. They represent only a summary overview and serve to highlight the core concepts that are addressed in the text. It should be anticipated that the students will provide more in-depth and detailed responses to the questions depending on an individual instructor’s stated expectations. Do you think that the advantages of organic agriculture (Core Case Study) outweigh its disadvantages? Explain. Do you eat or grow organic foods? If so, explain your reasoning for making this choice. If not, explain your reasoning for the food choices you do make. Many people are finding that organic agriculture is advantageous for various reasons. Personal health and health of ecosystems are commonly cited reasons. Many suggest that we should embrace sustainable approached to food production now, as food prices in a conventional system are closely tied to oil prices, because of the substantial energy requirements. As oil becomes scarcer and more expensive, it will become necessary for society to rely on more environmentally sustainable approaches. Nevertheless, many people cite cost as a reason for not embracing organic production.What are the three most important actions you would take to reduce chronic hunger and malnutrition: (a) in the country where you live, and (b) in the world? (a) In the U.S. I would: provide more food subsidy programs to underprivileged people, especially those with children in the household; educate about good nutrition and try to move people away from eating “junk” food; and provide free health care and immunizations especially for children and the elderly.(b) Globally I would: initiate programs that alleviate poverty; increase education of women, including nutrition and family planning programs; and provide sources of clean drinking water for children and adults.Explain why you support or opposed greatly increased use of: a) genetically modified food, b) organic polyculture, and c) hydroponic agriculture.Answers will vary but may include potential nutritional benefits of GMOs, decreased use of pesticides and potential increases in agricultural productivity. Note that none of these are completely clear-cut. Polyculture can aid biodiversity, promote genetic diversity in food crops, and may benefit smaller farms. Hydroponics is a wonderful option for developed nations (because of the investment required) that are dealing with water shortages and wish to reduce the use of chemical pesticides.Suppose you live near a coastal area and a company wants to use a fairly large area of coastal marshland for an aquaculture operation. If you were an elected local official, would you support or oppose such a project? Explain. What safeguards or regulations would you impose on the operation?Supporting or opposing the project will depend on student perspectives. Issues include such things as mangrove destruction, water pollution, and potential escape of organisms (genetically modified or otherwise) from the operation. Safeguards would be aimed at addressing these issues by protecting native mangroves and wetlands and improving management of wastes. Explain how widespread use of a pesticide can: (a) increase the damage done by a particular pest, and (b) create new pest organisms. (a) The target pest could develop resistance to the pesticide. All the susceptible members would be killed, but a small number may be genetically resistant to the pesticide and over several breeding generations could become a bigger problem than the initial outbreak. This is called a resurgence of the pest.(b) The pesticide could wipe out a species that may be a natural predator of another organism. Without the natural predator to hold the other organism population in check, their numbers could increase to the point that they now become a problem. This way an organism that previously was not considered to be a pest has now been turned into a “pest.”If a local mosquito population threatened you with malaria or West Nile virus, would you spray DDT in your yard and inside your home to reduce the risk? Explain. What are the alternatives?No, I would not spray DDT. I would use mosquito nets to sleep under in bedrooms, put screens on all doors and windows, make sure that there are no containers outside where standing water could collect, install many bat houses around the property, use an insect repellant like DEET, and wear long sleeves and long pants when I go outside.List three ways in which your lifestyle directly or indirectly contributes to topsoil erosion.Our lifestyles tend to support erosion indirectly by virtue of supporting conventional agriculture, supporting meat production systems that lead to overgrazing, and supporting industries that deforest or otherwise denude the landscape. According to physicist and philosopher Albert Einstein, “Nothing will benefit human health and increase chances of survival of life on Earth as much as the evolution to a vegetarian diet.” Are you willing to eat less meat or no meat? Explain.Answers will depend on the student—the argument to eat less meat (or different types of meat) however makes a great deal of sense from an environmental and resource use perspective.Congratulations! You are in charge of the world. List the three most important features of: (a) your agricultural policy, (b) your policy to reduce soil erosion, (c) your policy for more sustainable harvesting and farming of fish and shellfish, and (d) your global pest management strategy. (a) Agriculture: crop rotation, efficient irrigation, and use of organic fertilizers.(b) Soil erosion: limit grazing; promote contour farming and strip cropping; use no-till agriculture, and many other soil conservation strategies.(c) Fisheries: eliminate government subsidies on commercial fishing, mandate fish catches below the maximum sustainable yield, and establish a global monitoring organization. (d) Global pest management: use biological controls, introduce integrated pest management (IPM) strategies, and move towards polycultures rather than monocultures.List two questions that you would like to have answered as a result of reading this chapter.Student answers will vary and provide a good starting point for class discussion. ................
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