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.

Add golden rice = vitamin A.

A new – green revolution \

Transgenic crops

Some for economics

Some for production increase

Some for health.

Major advantage of transgenic

Crops – can develop quickly compared to traditional breeding

• 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.