chapter 11 notes - agriculture
-biological control (predator-prey)
-habitat manipulation (screens)
-modification of cultural practices (cleaning)
-use of resistant varieties
-use chemicals sparingly, avoid broad-spectrum and persistent pesticides - correct
answer-*green revolution-*
pesticides: techniques used in IPM
-breaks up soil compaction
-helps eliminate weeds
-incorporates cover crops for boosted soil fertility - correct answer-pros of tillage
-can increase crop yield and nutritional value
-reduces the need for pesticides
-saves money if pesticide use is limited - correct answer-*green revolution-*
pros of genetic engineering
-cheaper and more efficient machinery than human or animal labor
-contributes to economies of scale (cheaper if more volume) - correct answer-*green
revolution-*
pros of mechanization
-combustion of natural gas to fix nitrogen
-run-off into waterways & animal waste runoff from farms/feed lots= eutrophication
-doesn't replace organic components in soil (starves out soil organisms) - correct
answer-*green revolution-*
cons of synthetic fertilizers
-concern that new genes could cause harm to humans
-concern that genes transferred from one organism to another could also transfer allergens
-cross breeding with other crops or wild plant varieties = loss of biodiversity
-some consumers want mandatory GMO food labeling - correct answer-*green revolution-*
cons of genetic engineering
-confinement spreads disease
-overuse of antibiotics to prevent disease may lead to drug-resistant bacteria
-concentrated waste runoff can pollute waterways (eutrophication)
-methane production from animal waste
-not considered good quality of life for the animal - correct answer-cons of CAFOs
-destroys important fungal networks
-leaves soil vulnerable to erosion
-fuel and labor intensive
-lots of chemical inputs - correct answer-cons of tillage
, -encourages monocropping since most machines are crop specific
-leads to dependence on certain inputs (energy, chemical fertilizer, pesticides) - correct
answer-*green revolution-*
cons of mechanization
-exposes soil to erosion all at the same time
-more susceptible to disease/predators due to lack of genetic variation in the population -
correct answer-*green revolution-*
cons of monocropping
-increases crop yield
-turns un-farmable land into productive land
-allows some foods to be grown out of season - correct answer-*green revolution-*
pros of irrigation
-minimizes land cost
-improved feeding efficiency
-more food calories per energy unit invested - correct answer-pros of CAFOs
-reduced susceptibility to soil erosion
-less time used at seeding
-improved soil structure
-more organic matter
-less weed emergence
-less labor, fuel, and machinery costs per hectare
-improved long-term profitability and sustainability - correct answer-pros of no-till
-some are persistent
-persistent pesticides can bioaccumulate in consumers over their lifetime - correct
answer-*green revolution-*
cons of pesticides
-waterlogging (soil is underwater for long periods; impairs root growth)
-salinization (excess salts dissolved in irrigation water are deposited in soil and accumulate
to levels toxic to plants)
-salt-water intrusion (drawn into aquifer when fresh groundwater is pumped up)
-aquifer draw-down/depletion (using groundwater faster than the aquifer can recharge
naturally) - correct answer-*green revolution-*
cons of irrigation
1) plant cover crop
2) kill cover crop (with herbicide)
3) use grain drill machine to plant seed through the cover crop stubble on the surface -
correct answer-steps of no-till agriculture
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