Class Notes (836,580)
Canada (509,856)
Brock University (12,092)
Geography (209)
GEOG 1F91 (44)

Lecture Mar 27.docx

3 Pages
Unlock Document

Daryl Dagesse

Mar. 27, 2014 Soil Organic Matter • Humus, colloids, compost o Acts as a glue to hold soil together o Binds with clay to form “clay-humus complex”  Fig. 19.10 Soil Characteristics • Several diagnostic characteristics that give indications of what the soil is like o Colour  A reflection of chemical and biological processes operating in the soil  Certain diagnostic colours • Red: oxidized iron (well-drained) • Yellow: hydrated iron (poorly drained) • Black: highly organic (usually wet) • White: salty (usually dry) o Soil texture  Refers to the proportion of sand, silt, and clay present  Size of the mineral grains Fig. 19.5  Textural triangle  Texture controls number & size of pores  Controls moisture characteristics (e.g. pore pressure, eluviation/illuviation, water holding capacity) Fig. 19.13 o Structure  Soil doesn’t always operate as a series of individual particles  Held together by the clay content & organic matter  Single grain, blocky, platy, granular, prismatic, massive o Water holding capacity  Storage capacity • Held against gravity by capillary tension  Both wilting point and storage capacity are determined by soil texture Soil Horizons • Vertical variations in the soil o Based on:  Physical, chemical, and/or biological processes  Solid, liquid, and/or gas phases • Mineral horizons and layers o A, B, C, R, W • Organic horizons o O  f fibric material  m mesic material  h humic material o L  Accumulation of leav
More Less

Related notes for GEOG 1F91

Log In


Join OneClass

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

Sign up

Join to view


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.