food resources: a challenge for agriculture chapter 19
TRANSCRIPT
Food Resources: A Challenge for
Agriculture
Chapter 19
Food and Nutrition
Important molecules:• Carbohydrates - sugars, starches = energy (ATP)
• Proteins - 20 amino acids (essential amino acids)
• Lipids - fats & oil (energy, membrane, hormones)
• Minerals - inorganic salts - iron, calcium, iodine
• Vitamins - regulation of metabolic processes - rickets
First 3 metabolized by cellular respirationEssential Nutrient & Minerals
Available Plants400,000 estimated
species of flowering
plants
12 account for over
80% of the worlds
crops
Why few domesticated:Indigestible
Poisonous
Low Nutritional Value
Tedious to Prepare
Difficult to Gather
12 Major Species of Plant
Cereals: wheat, corn, rice, barley, sorghum, and soybeans
Roots: potatoes, manioc and sweet potatoes
Sugars: sugar cane, sugar beets, and bananas
Diversity & Heirloom Species
Global decline in domesticated plant and animal varieties
Heirloom: local varieties
Dutch Belted cow Heirloom Plants & Animals?
Heirloom
• Reliance upon modern varieties of rice caused more than 1,500 local rice varieties in Indonesia to become extinct.
• Almost 96% of the commercial vegetable varieties available in 1903 are now extinct.
Domestication of Plants
What makes a plant a good domestic candidate?
1.Size2.Mutant Pods & seed heads - did not pop or drop3.Earliest to ripen - at same time4.Self Pollinating5.Quick to grow6.Least care
Domestication of Animals
What makes an animal a good domestic candidate?
Animals:
1. Diet - readily available2. Rapid Growth Rate3. Captive Breeding 4. Disposition Reasonable5. Low Panic Levels6. Social structure & hierarchy
World Food Problems
• Malnourished – poor diet• Undernourished - too few calories• Famine - crisis of food supply
What causes famine?
Famine
Famines• 1983-1985 – Drought in Africa resulted in 1.5 million
deaths in Ethiopia and Sudan• 1993 – civil unrest and drought resulted in 2 million
starving Somalis• 1990’s – flooding and drought resulted in 2 million
deaths in North Korea
Primary causes of Famine:1. Drought2. Political Unrest3. Ecological Distress
Disease Resulting from Malnutrition
MarasmusKwashiorkor
Kwashiorkor - malnutrition causing fluid retention
Marasmus - low caloric and protein intake
Obesity
Producing Enough Food
Total Grain ProductionPer Capita Grain
Production
Grain Stocks
U.N. estimates that carryover stocks should not fall below 70 days from start of the next harvest.
Each year the world demand for grain climbs. Each year the world’s farmers must feed 80 million more people. In addition, some 3 billion people are trying to move up the food chain and consume more grain-intensive livestock products. And this year some 120 million tons of the 415-million-ton U.S. grain harvest will go to ethanol distilleries to produce fuel for cars.
Carryover stocks are the supply that is left over at the end of the marketing year. Marketing years for U.S. corn and soybeans end on August 31.
The First Green Revolution
1940’s -1970 – began in Mexico• High yield varieties – domesticated plants
bred specifically to respond to fertilizers• Increasing the amount of calories produced
per acre of agriculture
The First Green Revolution
1. Inorganic fertilizers
2. Irrigation
3. Pesticides + other “cides”
4. Monocultures
5. Aquaculture
6. Machine replaces human and animal labor
7. Oil Dependent
Environmental Concerns
Soil Erosion
Pollution – water & air
Lack of Water due to irrigation
Overgrazing by Livestock - desertification
Overfishing – stock reductions
Loss of Ecological Services
Live on CAFO (concentrated animal feeding operation)
• Fed Grains not grass• Antibiotics in feedstuff• Hormone supplementation
Bucolic?
Veal
Second Green Revolution? - GMO’s
Examples:1.Human hormone Producing plants2.Roundup Ready Corn, Soybeans, Cotton3.Bt Corn & Potatoes – insect dies of septicemia4.Arctic Char gene in strawberries – antifreeze5.Rapid growing fish
Issues with Genetic Engineering:1. The Safety of Genetic Engineering - Playing
GOD2. The Backlash Against Genetically Modified
Foods – Fear of Unknown Vs Reality - Frankenfoods
3. Should Foods from Genetically Modified Crops and Livestock Be Labeled? - Right to Know
Going Organic - going back?
Sustainable Agriculture
Keene Family FarmWalnut Acres
1. Fertilizer = animal and plant waste2. Integrated pest management3. Crop Rotations4. Crop choice for soil fertility (immune system)5. Cover Crop (alfalfa & clover)6. Soil Rest
Certified Organic - 3 years no inorganic fertilizers or pesticides
USDA Organic - animals fed certified organic
More $ = more labor / smaller quantities
