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Lecture 8

Environmental Science 1021F/G Lecture Notes - Lecture 8: Canadian Prairies, Sustainable Yield, Soil Fertility


Department
Environmental Science
Course Code
ENVSCI 1021F/G
Professor
Geoff Stewart
Lecture
8

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October 15th, 2012
Food and Land Continued . . .
Producing More Meat . . .
!Feedlots--> cattle video
!!-soil getting degraded
!!!-soil compaction from cattle’s hooves
!!!-reduce space for air and water
!!!!-soil not usable, less organic matter, not fertile
!!!-reduced moisture
!!-no plants---> reduce Net Primary Productivity
!!-most feedlots on grasslands!
!!-overgrazing-->no plant material
!!!-over = use above sustainable yield
!!!!!-rate that you can use a resource w/o degradation
!!-large amounts of waste generated
!!!-big waste lagoon
!!!!-man made to store waste
!!!-leeching of waste into soil
!!!!-high nitrogen, antibiotics, hormones
!!-use of grain--->lots needed
!!!-agricultural land used to feed livestock, not ppl
!!-methane source-->especially cattle
!!!-more potent greenhouse gas than CO2
!!!-but less abundant
!-increase in development = increase in meat production
Producing More Fish . . .
!55% of fish now from open ocean fisheries
!!-7% of population rely on this (increasing)
!Fisheries: (entirely wild)
!!-75% are overfished
!!!-use above sustainable yield
!!!-so few left to breed, no longer commercially viable
!!!!-commercial extinction
!!!!!-no longer economically viable
!!-many fisheries highly subsidized
!!!-w/o would have a 50billion $ deficit
!
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