Chapter 12: Food. Read pgs

Transcription

1 Chapter 12: Food Read pgs

2 I. Key Concepts 1. Understand the methods of producing food 2. Explain how we can increasing food production 3. Identify the environmental effects of food production 4. Steps to increasing sustainability

3 How would you separate this food?

4 Where does our food come from? 1. CROPLANDSi. Mainly three crops (rice, corn, & wheat) provide half the calories. ii. Top 5 most important crops grown: 1. Sugarcane; 2. Corn; 3. Rice; 4. Wheat; 5. White Potato. 2. RANGELANDS (beef, poultry, pork) 3. OCEANIC FISHERIES- important mainly in Asia.

5 II. Comparison between Traditional to Modern Agriculture A. Traditional Agriculture (Low-Input) Traditional: subsistence & intensive agriculture. i. Subsistence enough for family ii. iii. iv. Intensive enough for family plus some to sell for income. Relatively small acreage (but can be land intensive) Mostly human labor and draft animals. (Sometimes few machines) Shifting cultivation Slash-and-burn cultivation Nomadic herding Intercropping v. Regionally-appropriate crops

6 B. Industrialized/Plantation Agriculture (High-Input) i. Large acreage ii. Monoculture iii. Large inputs of energy and capital. iv. Extensive use of fossil fuels Extensive use of machinery Extensive use of fertilizers Extensive use of pesticides Extensive use of irrigation High yields v. Encouraged to select of high cash crops despite location. vi. Crop selection for animal feed

7 World Agriculture Distribution Industrialized Agriculture Plantation Agriculture Shifting Cultivation Nomadic herding Intensive traditional agriculture No agriculture Fig. 12.2, p. 263

8 C. Impacts of Industrialized farming. i. Runoff of fertilizers from agricultural lands has affected the water quality. ii. Erosion is a serious environmental problem in the absence of preventative measures. iii. Irrigation can be a significant drain on water supplies in arid areas and can lead to buildup of salt deposits. iv. High use of fossil fuels to run the farm equipment and making the fertilizers/pesticides. v. What else?

9 D. Farming facts for Pennsylvania Statistics i. Farms 63, 200 (2009) 58,105 (Full and part-time operators 2002) ii. State population 12,321,644 (2002) iii. Land in farms (acres) 7, 750, 000 in 2009 (7,745,336 in 2002) iv. Total land area (acres) - 28,682,630 v. Most valuable crops: Corn, Hay, & Mushrooms i. Livestock: Milk Production, Egg Production, & Chickens (Broilers) vi. Agricultural land converted to developed uses (acres) - 244,500

10 E. The Green Revolutions i. Farmers have two options in producing more food Farming more land Increasing yield from the existing land ii. Emphasis has been on the second option. iii. A green revolution is a process of increasing the yield per unit of area. 1 st Green Revolution occurred in developed countries around nd Green Revolution occurred in developing countries (from investments from developed countries) since 1970.

11 Green Revolutions First green revolution (developed countries) Second green revolution (developing countries) Major International agricultural research centers and seed banks Fig. 12.4, p. 265

12 F. Green-Revolution Techniques i. High-input monoculture ii. Selectively bred or genetically-engineered crops iii. High inputs of fertilizer iv. Extensive use of pesticides v. High inputs of water vi. Increased intensity and frequency of cropping

13

14 G. How can we increase food production? i. Crossbreeding and artificial selection ii. Genetic engineering (gene splicing) iii. Genetically modified organisms (GMOs) iv. Continued Green Revolution techniques v. Introducing new foods vi. Working more land

15 H. Agricultural Policy and Food Aid Options most governments use to keep a reliable food supply. i. Artificially low prices keep consumers happy but hurts farmers. ii. iii. iv. Subsidies - supports farmers but can cause overproduction which drives down prices which hurt farmers. Elimination of most or all price controls let a free market decide prices and amounts of food produced. Food aid short term positives and long term negatives.

16 I. Nutrition Basic requirements: 1. Carbohydrates supply energy required to maintain life. Can be broken down into glucose. Good Carbs fruits, vegetables, whole grains Bad Carbs Soda, candy, white (bread, pasta, rice) Look at the glycemic index. Lower the number the better. 2. Proteins 20 different amino acids. The human body can produce 12 of these themselves from chemicals found in your body. However, the remaining 8 amino acids need to be obtained from food. Mainly from meats, eggs, and milk. Vegetable sources are not as complete. (soy, nuts, beans) These 8 amino acids are called the essential amino acids.

17 Essential Amino Acids Isoleucine Methionine Lysine Phenylalanine Tryptophan Threonine Valine Leucine Non-essential Amino Acids Alanine (from pyruvic acid) Arginine (from glutamic acid) Asparagine (from aspartic acid) Aspartic Acid (from oxaloacetic acid) Cysteine Glutamic Acid (from oxoglutaric acid) Glutamine (from glutamic acid) Glycine (from serine and threonine) Histidine Proline (from glutamic acid) Serine (from glucose) Tyrosine (from phenylalanine)

18 3. Lipids (fats/oils) provide a higher level of energy when compared to carbohydrates. Important for the synthesis of hormones and essential cell membranes. Good lipids plant based, unsaturated, HDL-C (High density lipoprotein cholesterol) Bad lipids animal based, saturated, trans fat, LDL-C (low density lipoprotein cholesterol) Avoid things that say hydrogenated 4. Vitamins/Minerals essential inorganic/organic molecules. Water soluble - Vitamin C, B complex (B1 (Thiamine), B2 (Riboflavin), B3 (Niacin), B5 (Pantothenic acid), B6 (Pyridoxine) and B12 (Cyanocobalamin), Folic acid. Fat soluble Vitamin A, D, E Most important essential minerals calcium, iron, zinc Most important trace minerals iodine, chromium

19 Undernourished Receiving fewer calories than their bodies need daily. Men (on average) need 2500 calories a day. Women (on average) need 2000 calories a day. Children (on average) need 1800 calories a day. o Severe effects on the human body. Can lead to disease, starvation, and death.

20 Malnourished Receiving enough calories in the diet but still not receiving enough of the specific, essential nutrients such as proteins or vitamins. Typical of poor income families or countries. May rely on one food source or in the U.S. fast food.

21 Marasmus (from the Greek word marasmos meaning wasting away. A progressive emaciation caused by a diet low in total calories and protein. Symptoms include a pronounced slowing of growth and extreme atrophy. REVERSIBLE WITH AN ADEQUATE DIET.

22 Kwashiorkor Native word in Ghana meaning displaced child. Nursing child is displaced by a newborn. Malnutrition from protein deficiency. Symptoms include edema; dry, brittle hair; apathy; stunted growth; sometimes retardation. Most noticeable with a pronounced swelling of the abdomen. REVERSIBLE BY RESTORING A BALANCED DIET.

23 Overnutrition Eating food in excess of what is required. Diet tends to be high in saturated fats, sugar, and salt. Results in obesity, high blood pressure, diabetes, and heart disease. Most common in developed countries but rising problem in developing countries (especially in urban areas).

24

25 J. Genetic Engineering 1. Genetic engineering is the manipulation of genes, for example, by taking a specific gene from a cell of one species and placing it into a cell of an unrelated species, where it is expressed. Different from traditional crossbreeding: by speeding up the process (from decades to years) that genes from any organisms can be used, not just from the species of plant or animal being improved. 2. Genetically Modified crops approved in the early 1990s. U.S. top producer of GM crops: 80% of soybean acres; 70% of cotton acres and 38% of its corn acres. Should foods from genetically modified crops and livestock be labeled? Should be cloned crops and livestock be labeled?

26 K. Meat Production 1. Most of the meat produced in the U.S. is done by a few large agribusiness conglomerates. Traditional farms give way to livestock factories and feedlots. In livestock factories, thousands of animals are confined to small pens. Most are fed and watered by machines. Can produce as much sewage as a small city. The manure is typically stored in deep lagoons. 2. Rangelands are grasslands that serve as important food production for humans by providing fodder for livestock such as cattle, sheep, and goats. If carefully managed, the grazing is beneficial for the grassland. If the animals exceed the carrying capacity of the land, it can lead to overgrazing which leads to degradation and desertification.

27 L. Fisheries 1. Ocean contains valuable food resources: 90% fishes; 6% mollusks; 3% crustaceans; 1% algae. 2. Problems with the Fishing Industry. Tragedy of the Commons no one owns the ocean. Most marine species have been or are close to being overharvested. Bycatch unintentional species caught and then discarded. 3. Aquaculture is the growing of aquatic organism for human consumption. Can be done in both fresh and saltwater. Catfish, tilapia, salmon, shrimp and oysters are the most important types of seafood grown by aquaculture in the U. S.

28 M. Solutions: Sustainable Agriculture 1. Sustainable agriculture are methods that maintain soil productivity and a healthy ecological balance while having minimal long-term impacts. Organic farming Integrated pest management Has lead to a new greener green revolution.