chapter 11Review
In this chapter, we examined human nutritional requirements and contemporary problems of undernutrition and overnutrition. Modern industrial agriculture in the developed world uses large amounts of fossil fuel inputs and relies on other practices such as irrigation, fertilization, and pesticide application. Genetically modified organisms are also a component of modern agriculture in many parts of the world. Raising meat and fish have specific environmental impacts related to concentrated feeding areas for meat and removal of large numbers of fish from the oceans. Alternatives to conventional modern agriculture exist and often make use of natural patterns observed in nature such as crop rotation and interplanting different species. Organic agriculture is an agricultural practice that does not use chemical pesticides or fertilizers. A variety of sustainable organic and other alternative agricultural practices are being utilized in a variety of locations around the world.
385
Module 31 Human Nutritional Needs
Describe human nutritional requirements.
Humans require both a certain number of calories each day and a balance of proteins and other nutrients. Undernutrition is a condition in which not enough food calories are ingested each day. Malnutrition is a condition in which the diet lacks the correct balance of proteins, carbohydrates, vitamins, and minerals.
Explain why nutritional requirements are not being met in various parts of the world.
Malnutrition occurs due to poverty and political situations that prohibit the efficient and equitable distribution of food. In addition, some grains that could be fed to humans are used to feed livestock and are not available for direct human consumption.
Module 32 Modern Large-
Describe modern, large-
In the twentieth century, a variety of modern agricultural innovations including the Green Revolution transformed agriculture from a system of small farms relying mainly on human labor into a system of large industrial operations that use machinery run by fossil fuels. This shift has resulted in larger farms and monocropping. Irrigation can increase crop yields dramatically, but it can also draw down aquifers and lead to soil degradation through waterlogging and salinization. Fertilizers also increase crop yields dramatically, but can run off into surface waters and cause damage to ecosystems. The negative environmental consequences of pesticides include loss of beneficial nontarget organisms, human health problems, and surface water contamination. When pests become resistant to pesticides over time, a pesticide treadmill can develop.
Explain the benefits and consequences of genetically modified organisms and large-
Agricultural scientists are using genetic engineering to produce genetically modified organisms with desirable traits. GMOs can increase yields and reduce the use of pesticides. Concerns about GMOs include safety for human consumption and their effects on biodiversity. Concentrated animal feeding operations and aquaculture facilities enable efficient animal growth and economically inexpensive food production. However, the disposal of concentrated animal waste presents a problem and the environment can be harmed by runoff containing antibiotics and other waste products.
Module 33 Alternatives to Industrial Farming Methods
386
Describe alternatives to conventional farming methods.
Traditional farming techniques such as intercropping, crop rotation, agroforestry, and contour plowing can sometimes improve agricultural yields and conserve soil and other resources. No-
Explain alternative techniques used in farming animals and in fishing and aquaculture.
Free-
Wild-