Class Notes (834,384)
Canada (508,507)
POL469H1 (23)
M.Isaac (22)
Lecture 3

IDSB02 lecture 3.docx

3 Pages
67 Views
Unlock Document

Department
Political Science
Course
POL469H1
Professor
M.Isaac
Semester
Winter

Description
IDSB02 Development and Environment: Lecture 3 Tuesday January 24 2012 SOIL  Soils very important and now recognized, we are now relating soil science and the environment and ecology  Food security, food production, and also water contamination is central to the soils st nd  Breaking the Sod: Soil erosion, like the Mayan empire was the 1 wave, 2 wave was the plow, 3 wave was the green revolution and a push into susceptible soils like Amazon rainforests  Soil Management:  Poor soil management factors include; depletion, erosion, soil salinization and  Soil classification/knowledge  Development of soil science  Pedospheres: a bit of everything; air water and minerals, which are all main parts of the soils  Soils are highly diverse and variable, soils have many classifications/orders etc. (diverse like species)  Red soils have iron and aluminum, which are characteristics of tropical soils  Reducing conditions often grey- filled with air no water (do not need to know)  Soil profiles: typically broken down into horizons  HORIZON A: crop growth, top layer  HORIZON B: secondary layer  HORIZON C: parent material  Soil profiles can help understand how a soil will behave  How does rock turn to soils; mineral weathering of soils, could be physical weathering (wind, rain etc; sand and silt are an example of this weathering), chemical weathering (example of this type of weathering clay) or biological weathering  Dynamic natural bodies having properties from the combined effect of climate and biotic activities, as modified by topography (where you are on a hill), acting on parent material (rock) over periods of time.  These five factors are what makes up a soil  Soil texture  Sand – like tiny little rocks  Silt – in between, like bigger pieces of rock  Clay – it has gone under chemical weathering and changes the structure of the rock; it has an enormous surface area and has many inner microscopic sheets inside itself  Soil textures and properties; can help determine the behaviours and predictability of them; sand and clay examples of opposites – at a beach putting water in sand goes straight through while cups/mugs are made of clay which hold water  Table on slide 18 – know the basics  Soil Structure:  Imagine a house, the material it is built out of is soil texture- you cannot change it, but the shape of the room is the structure – it is malleable (how they are all shaped together)  4 different shapes – spheroidal, platelike, blocklike, prismlike  You would find prism like structures in dry salty (salinized
More Less

Related notes for POL469H1

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit