BIO 141 1st Edition Lecture 23 Outline of Last Lecture II. AztecIII. Three SistersIV. Co-evolutionOutline of Current Lecture V. HistoryVI. Green RevolutionVII. EutrophicationCurrent LectureHistory- 1st plow technology: scratch plows (animals drag stick under ground)o Limits areas we can actually farmo Only able to plow light soilso Only need 2 oxeno Led to square field sustaining a family unito Families would go dump their waste in the field were the soils need the nutrientso Decomposition: recycles nutrients in natural ecosystems- 8th century: the moldboard plow allows tilling heavier soilso Needs more oxeno Used military technologyo When clay soil is needed at least 6-8 oxen are needed, which is more than the normal farmer owned, so everyone shared and communal fields came about- Commoditization of Agricultureo The closed loop isn’t closed anymoreo Had to figure out a way to get fertilizer out thereo Crops (nutrients, organics) removed from fieldo Decomposition cannot recycleo TNT is very high in nitrogen o Without nitrogen source it was hard to continue warfareGreen RevolutionThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- 1940s to present: increase to yield of crops so that people can have more to feed/clothe themselves- Yield: how much crop you can get out of a piece of land- Pioneer: Norman Borlaugo Food chemist that helped save 1 billion people- Organico Often increased tillageo Reduced chemical Nitrogen use- GMOo Can have reduced tillageo Increased nutrient application- Often a false comparison, more apt would be large vs. small agricultureOverall Impacts of Green Revolution- Increases in food production- Famine decreased by 20%- 25% increase in per capita calorie intake Mechanisms/Accomplishments of the Green Revolution- Better irrigation, irrigation increases productivity- Increase fertilizers- Increase pesticides/herbicides- Additional plant strains – high yielding varieties (HYVs)- Technology/Biotechnology – resistance to drought/pests/etc.Eutrophication- Increased plant/algae growth due to increased
View Full Document