Chapter 12: Food
Transcript of Chapter 12: Food
Chapter 12: Food
Read pgs. 261-291.
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
How would you separate this food?
Where does our food come from?1. CROPLANDS-
i. 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.
II. Comparison between Traditional to Modern AgricultureA. Traditional Agriculture
(Low-Input)
Traditional: subsistence & intensiveagriculture.
i. Subsistence – enough for family
ii. Intensive – enough for family plus some to sell for income.
iii. Relatively small acreage (but can be land intensive)
iv. Mostly human labor and draft animals. (Sometimes few machines)
Shifting cultivation
Slash-and-burn cultivation
Nomadic herding
Intercropping
v. Regionally-appropriate crops
B. Industrialized/Plantation Agriculture(High-Input)
i. Large acreageii. Monoculture iii. Large inputs of energy and
capital. Extensive use of fossil fuels Extensive use of machinery Extensive use of fertilizers Extensive use of pesticides Extensive use of irrigation
iv. High yieldsv. Encouraged to select of high
cash crops despite location.vi. Crop selection for animal
feed
World Agriculture Distribution
Fig. 12.2, p. 263
Industrialized AgricultureShifting Cultivation
Plantation AgricultureNomadic herding
Intensive traditional agricultureNo agriculture
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?
D. Farming facts for PennsylvaniaStatisticsi. 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, & Mushroomsi. Livestock: Milk Production, Egg Production, & Chickens (Broilers)
vi. Agricultural land converted to developed uses (acres) -244,500
E. The Green Revolutionsi. 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.
1st Green Revolution occurred in developed countries around 1950.
2nd Green Revolution occurred in developing countries (from investments from developed countries) since 1970.
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
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
G. How can we increase food production?
i. Crossbreeding and artificial selectionii. Genetic engineering (gene splicing)
iii. Genetically modified organisms (GMOs)
iv. Continued Green Revolution techniques
v. Introducing new foods
vi. Working more land
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. Subsidies - supports farmers but can cause
overproduction which drives down prices which hurt
farmers.
iii. Elimination of most or all price controls – let a free
market decide prices and amounts of food produced.
iv. Food aid – short term positives and long term
negatives.
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.
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)
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
UndernourishedReceiving 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.
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.
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.
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.
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).
J. Genetic Engineering1. 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?
K. Meat Production1. 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.
L. Fisheries1. 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.
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.