1. Food Chapter 9

2. Feeding the People of the World Chapter 9 Section 1 Read page 227!

3.  The main types of organic molecules in all foods are carbohydrates, proteins, and lipids. See Figure 9-2,pg 228  In addition to these major nutrients, we need smaller amounts of vitamins and minerals to help our bodies function properly  The human body uses food both as a source of materials for building and maintaining body tissues and structures.  When people do not get enough to eat, they can become sick and even die….when starving people die, it is usually as a result of diseases that their bodies cannot fight…diseases that do not threaten the lives of well-nourished people

4. Malnutrition  Even if people consume enough calories in the food they eat, they may still suffer from malnutrition.  Malnutrition: condition caused by not consuming enough necessary nutrients.

5. Why People Go Hungry  Because the human population is increasing more rapidly than food production can keep up with.  If everyone in the world today received an equal share of all the food produced, no one would have enough to stay strong and healthy  The world’s food is not divided equally…in many parts of the world, wealthy people have an abundance of food, while poor people have much less than they need.  We often think of malnutrition as something that happens only in developing countries…but even in the United States many poor people suffer from malnutrition.

6. Why People Go Hungry

7.  1950-1970  In an effort to increase crop yields, new varieties of grain were introduced in Asian and Latin American countries during this time period  These new varieties had much greater Yield (amount produced per unit area) than old varieties.  The green revolution allowed far more people to be adequately fed than was possible before….however….

8.  The new varieties of grain did not grow well without the right kinds of fertilizers and pesticides, or without sufficient water.  Many subsistence farmers (those who can only grow enough food to feed their family) could not afford the necessary equipment and chemicals.  The use of large amounts of pesticides and fertilizers pollutes the environment.  Also, the necessary farm machinery consumes a great deal of energy, as does the manufacture of fertilizers and pesticides.

9. Agriculture and Soil Chapter 9 Section 2

10.  Bama soil is the official state soil of Alabama as of 1996  Bama soils occur in 26 counties of Alabama on more than 360,000 acres in the state  Bama soils are well drained, have desirable physical properties, and are located on high positions of the landscape  Are well suited for most agricultural and urban uses  Cotton and corn are the principal cultivated crops grown on these soils

11. Types of Soil Carousel Activity  Your assigned group will create a flyer about your type of soil using the provided handouts  Your group will then display your flyer somewhere in the classroom  When all groups have finished, you will walk about the room and collect information about all of the types of soil displayed in the room on your foldable.

12. Arable Land  Fertile land that can be plowed to grow crops  The Earth has a limited amount of arable land and this amount decreases every year.  The amount of arable land in the world will have decreased by about 1/5 from 1985- 2000.  About 371 million acres of farmland will be covered with houses, mines, roads, factories, and power plants.  Another 334 million acres will become unusable for farming because the soil will be damaged…

13.  Basic techniques: plowing, fertilization, irrigation, and pest control…began with the earliest farmers  People or animals pulled the plows through the soil. Plowing the soil helps crops grow by mixing up soil nutrients, loosening soil particles, and uprooting weeds.  Organic fertilizers, such as manure, were used to enrich the soil so that plants would grow strong and remain healthy.  Fields were irrigated (supplied with water) by digging ditches for water to flow through.  Weeds were removed by hand, and some plants were covered to keep out pests.

14.  These ancient methods are still used today….however, new methods are also used in industrialized countries  Machinery is used to plow the soil and harvest crops  Synthetic fertilizers, which are produced in factories, are used instead of manure and plant wastes.  A variety of overhead sprinklers and drip systems are used for irrigation.  Many different synthetic chemicals are used to kill pests.

15.  Is soil that can support the rapid growth of healthy plants  Most plants grow in topsoil, the loose surface layer of soil.  Fertile topsoil contain many things that help plants grow  Water  Air  Organic matter (dead plants, animals, and animal excrement)  Living organisms (fungi, bacteria, earthworms, insects)

16. Bedrock  Several other layers of soil lie under the topsoil  At the bottom is bedrock, which is solid rock  Most soil is formed from bedrock  Temperature changes and moisture cause the bedrock to crack and break apart  Creating smaller and smaller particles  The combination of rock particles, water, air, decaying organic matter, and the action of living organisms forms the soil. It may take THOUSANDS of years to form a few centimeters of soil!

17. Living organisms are crucial to maintaining the fertility of soil. The table shows the astounding number of organisms in farm soil. OrganismsQuantity Insects23 million/hectare All arthropods (includes insects) 725 million/hectare Bacteria2.5 billion/gram Algae50,000/gram Earthworms6 million/hectare

18. Topsoil Erosion  Erosion: The wearing away of topsoil by wind and water  In the US, about half of the topsoil has been lost to erosion in the past 200 years.  Worldwide, it is estimated that about 11% of the soil has been eroded in the last 45 years  Topsoil erosion is ranked as one of the most serious ecological problems we face!  Without valuable topsoil, crops cannot be grown to feed the world’s people.

19. Contributing to Topsoil Erosion…  1. Certain farming practices  Plowing produces a loose surface layer of soil that is easily blown away by wind or washed away by rain  Also, harvesting may remove roots and other organic matter that hold soil together  2. Clearing of forests to produce lumber  Trees and shrubs absorb large quantities of water  When they are cut down, the amount of water running off the surface of the soil increases  More soil gets carried away  Sometimes, the soil washes away slowly, and sometimes large amounts wash away in landslides!

20.  Is a process where soil fertility can deteriorate so much that the land becomes desert-like.  The loss of topsoil occurs all over the world, but is especially severe in dry areas.  Soil in these areas is easily destroyed because it is naturally thin.  Worldwide, an area the size of Nebraska becomes desert each year!

21. Soil Conservation…4 Big Ways! 1.Contour Plowing  Plowing across the slope of a hill  The plow forms tiny ridges that help prevent the soil from washing down the hill

22. Soil Conservation…4 Big Ways! 2.Strips of Vegetation  Leave strips of vegetation running across a hillside instead of plowing the entire slope  These strips catch soil and water that run down the hill  In very hilly areas, the best method of conserving topsoil may be not to farm the land at all but instead use it as a forest or grassland if possible.

23. Soil Conservation…4 Big Ways! 3.Organic material  Using organic material instead of inorganic fertilizers can help restore soil  One type of organic material that can be used as fertilizer is compost (waste plant material that has been placed in piles and allowed to decompose)  Animal manure can also be used as fertilizer

24. Soil Conservation…4 Big Ways! 4.No-Till Farming  In conventional farming, after a crop is harvested, the soil is plowed to turn it over and bury the remains of the harvested plants  Then it is raked before new seeds are planted  In no-till farming, the seeds of the next crop are planted in the slits that are cut into the soil, straight through the remains of the previous crop  The roots of the first crop hold the soil in place while the new crop develops. And as the remains of the first crop decay, organic matter is added to the soil  No-till farming saves time and can reduce soil erosion 1/10 of the amount caused by conventional farming!

25. Sustainable Agriculture How can we continue to feed the world’s population without continuing to deplete the world’s resources?  One answer is Low-Input Farming : farming without using a lot of energy, pesticides, fertilizer, and water.  Types of Low-Input Farming: 1.Organic farming ….growing plants without any synthetic pesticides or inorganic fertilizers. Organic farmers keep the soil moist and fertile by adding manure, compost, and other organic matter, by keeping the soil planted at all times to avoid erosion, and by alternating different crops to reduce pest populations. In addition to protecting the environment, organic farming reduces the need for water, pesticides, and fertilizer. 2.Aquaculture or “fish farming”, raising fish in artificial environments…more to come on this.

26. Salinization  Salinization: the accumulation of salts in the soil  Although all soil naturally contains some salts, more salts are added when land is irrigated  This is because water for irrigation is taken from rivers or groundwater, which contain more salt than rainwater does  When land is irrigated, much of the water evaporates, leaving behind the salts it contained.  Eventually, the soil may become so salty that plants cannot grow in it!

27. Preventing or Slowing Salinization 1.Can be slowed by careful irrigation methods…For example, irrigation canals can be lined to prevent water from seeping into the soil and raising the groundwater level 2.Water the soil heavily to wash out salts before seeds are planted…this helps protect young seedlings, which are more harmed by salt than older plants 3.Planting salt-tolerant crops, which absorb salt from the soil 4.Planting trees…shade from tress reduces the amount of water that evaporates from the soil surface. Tree roots penetrate the soil, allowing rainwater to sink in and wash out salts more rapidly. AND fallen leaves improve the soil by adding organic matter….Leave it to the trees to be awesome once again!

28. Pick up the Soil Contamination sheet from the side counter, read it, and then answer the following questions on your own paper  What are 3 ways a human could be hurt by soil contamination?  How is soil contamination contained?  How does soil become contaminated?  How does a plant become contaminated by soil?  What are the 3 general approaches to cleaning up contaminated soil?

29. Pest Control Chapter 9 Section 3

30.  In North America, insects destroy about 13% of all crops  Crops in tropical climates suffer even greater insect damage because the insects grow and reproduce faster  Worldwide, pests destroy about 1/3 of the world’s potential food harvest  Clearly, pest damage must be controlled in order to feed the world’s people

31. Pesticide: Substance that kills pests  During the last 50 years, many new chemical pesticides were invented  Some of the main pesticides include (Fig.9-21, pg.241)  Aldrin, DDT, Lindane: All Toxic and Persistent (half-life:2-5 years)  Malathion, Parathion: Both Toxic but Degradable (half-life:1-10 weeks)  Carbaryl, Zectran: Both Toxic but Degradable (half-life:1 week)  Pesticides that kill insects are called insecticides…they were so effective that farmers began to rely on them almost completely to protect their crops.

33.  Biological Pest Control: The use of living organisms to control pests  Pathogens: Organisms that causes disease and can control pests  Plant Defenses: When farmers breed plants to have defenses against certain pests  Disrupting Insect Breeding: Use of pheromones to confuse male insects and interfere with mating  Chemicals from Plants: Some plants actually produce their own chemical that kills pests…so scientists will extract these chemicals and use them as pesticides Other Forms of Pest Management:

35. Animals and Agriculture Added Section from Alternate Text

36. Animals and Agriculture Added Section from MS Book We have been using animals for food for a long time. Our ancestors obtained animals to eat by hunting and fishing, but today we typically get our animal protein from domesticated species. Domesticated : species that are bred and managed for human use There are about 50 domesticated animal species including: chicken, sheep, cattle, honey bees, silkworms, fish, and shellfish.

38. Solution for Overharvesting: Aquaculture: The raising of aquatic organisms for human use or consumption. Examples: Fish Farms & Oyster Farms

39. Livestock: Domesticated animals that are raised to be used to farm or ranch or be sold for profit. Livestock is mainly used for meat in developed countries, but in developing countries livestock provides leather, wool, eggs, and serve as draft animals to pull carts and plows.

40. Ruminants: Cud-chewing mammals that have 3 or 4 chambered stomachs. Cud is the food that these animals regurgitate from the first chamber of their stomachs and chew again to aid in digestion. Ruminants have microorganisms that live in their intestines that allow the animals to digest plant materials that humans cannot digest. When we eat the meat of ruminants, we are using them to convert plant material into food that we can digest-such as BEEF.

41. Poultry : domesticated birds raised for meat and eggs. Example: Chickens and Turkeys In China, ducks are a type of poultry that are not only used as meat, but also for their droppings…. Ducks droppings in China are used to fertilize fields of rice called Rice Paddies!