Transcript Slide 1
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.