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Food and agriculture
Major topic not covered in biology courses
Involves:
Habitat loss – conservation issues
Nutrition – body maintinence and disease
Human population
Thomas Malthus
1766~1834.
Food production is arithmetic, population
growth in geometric = too many people not
enough food.
• Under nutrition – not enough calories
• Malnutrition – missing some vital
ingredient.
Note: nobody dies of either one – you die of something else due to
weakend body.
Why has the population bomb not gone off ??? What got better?
Outline:
nutritional needs
calories
food crops
malnutrition and undernutrition
food production
historical
green revolution
new methods
Nutrition:
3 molecular food types
Sugar
4 calories/gm
- free in blood, first used
Fat (lipid)
9 calories/gm
- stored – 2nd used
Protein
4 calories/gm
- last used – first protein used is in blood =
antibodies
Body needs
energy - see next page
vitamins – enzymes and enzyme helpers the body can’t make
minerals – calcium – rickets, vitamin c – scurvy, Vit A – night blindness
Iron – anemia (2/3 of college women deficient
8 essential amino acids – 8 of 21 the body can’t make
One ¼ pounder = all you need for protein
In talking about food, we need only talk about three major crops = most food
especially in underdeveloped countries.
Note: embryo contains vitamins, minerals, amino acids
body of seed = starch (energy only)
husk = ruffage.
(white flour – enriched!!)
Rice, wheat and corn barely have enough protein, and not the right kind.
Note: in undeveloped countries protein sources =
Bush meat – africa / fish - Asia
Traditional Diets
• Corn - low in essential amino acids – add
beans
• Rice – low in essential amino acids – add
lentils,
• Wheat – better, but add beans, etc.
History of Agriculture
• Permanent crop – fertile crescent; flood
plains (natural fertilizer, irrigation)
• Slash and burn – poor soils – fallow period
• Continuous cropping = fertilizer, irrigation
• Mechanization ;Multi- croping
Why the 1980 increase in yield? = genetics!!!
Note also the basis of rural to urban migration in U.S.
Green revolution -
Father of the Green Revolution; During the mid-20th century, Borlaug led
the introduction of these high-yielding varieties combined with modern
agricultural production techniques to Mexico, Pakistan, and India. As a
result, Mexico became a net exporter of wheat by 1963. Between 1965
and 1970, wheat yields nearly doubled in Pakistan and India, greatly
improving the food security in those nations.[4]
Later applied to rice – Rockefeller foundation support
? = why no increase in production in developed world??
Basis of rural to urban migration???
Other agriculture issues
Overuse of fertilizer: how much should you add???
Monoculture issues
Banana wilt rots the fruit before harvest and eventually kills
the tree
Almost all bananas in the world are cavendish strain – ripens slow –
Has decimated banana production in Africa, now affecting S. America
Effect on exports to Europe?
Solution: find a resistant strain.
Kills wheat – effect on Ethiopia – major food crop. Etc. A wind borne fungus
Potato blight
In Ireland, the Great Famine was a period of mass starvation, disease
and emigration between 1845 and 1852.[1] It is also known, mostly
outside of Ireland, as the Irish Potato Famine
During the Famine, Ireland's population fell by between 20 and 25%.[3]
Approximately 1 million people died and a million more emigrated from
Ireland.[4] The proximate cause of famine was a potato disease
commonly known as potato blight.[5] Although blight ravaged potato
crops throughout Europe during the 1840s, the impact and human cost in
Ireland — where a ⅓ of the population was entirely dependent on the
potato for food
Irish potato famine – millions left for U.S., Australia, etc.
Major advantage of transgenic
Crops – can develop quickly
compared to traditional breeding
Add golden rice = vitamin A.
A new – green revolution \
Transgenic crops
Some for economics
Some for production increase
Some for health.
• Issues today – food distribution vs food
production
• Weather patterns and water availability.
• Extreme weather – frost and heat. –
survival of worst conditions
If certain areas get drier, or more severe weather (spring floods, etc.) effect on
corn production ?
Drier summer – move corn to Canada.