Download principles of soil science lwr 105

MIDLANDS STATE UNIVERSITY
DEPARTMENT OF LAND AND WATER
RESOURCES MANAGEMENT
PRINCIPLES OF SOIL SCIENCE ( NRM/
LWR 105) COURSE OUTLINE
1 The Importance of Soils
1.Soil uses
2.What is a Soil? - Brady
1.Soil definition
2.Terminology used in describing soils
3.Profile variability - soil horizons,
catena
4.Topsoil vs. Subsoil- differences
5.Components of soils - diagram circle
3.Jenny’s theory of soil formation
1 Parent
material,
climate,
relief,
vegetation, and time but there are other
minor ones S…..f( CL, PM, T, R,Org….)
2 Weathering as a process of soil
formation
processes,
chemical
(hydrolysis), biological and physical
(exfoliation, hydration)- differences
3 Soil processes – leaching, glorying,
eluviation, illuviation, podzolization and
gleying. Most of these manifest
themselves in colour development Soil
colour
3. Soil Classification
(Zimbabwe)
and
Survey
1 The need for classification
2 Zimbabwe soil classification- orders,
groups’ family
3 Soil uses and constraints
4
Soil Physical Properties
a. Soil texture, soil mechanical analysis
and texture determination (field and
lab) stokes’ law
b.
Soil structure
c. Soil colour
d. Soil permeability
e. Bulk Density def, factors affecting
two methods of BD
f. Soil porosity
5 Soil Water
a.
Importance of water
b.
Types of Soil water e.g.
hygroscopic, adhesive
c. Moisture constants (saturation, field
capacity, wilt point, hygroscopic
coefficient)
d.
Soil moisture equations and
calculations
e. Measurement of soil water e.g.
neutron probe, use of gravimetric
method
f. Factors affecting water holding
capacity of soils - (texture,
consistence,
structure,
organic
matter)
g.
Soil water movement- pores look
for the word (tortusity (sp))
6 Soil chemical properties
a. Soil colloids - organic versus
inorganic, types of clay, nature of
clays (structure, negative charges
development, relationship to cation
exchange)
b.
Cation exchange see the H and
Ca example
c. Cation exchange capacity (CEC)
d.
Factors affecting CEC
7 Soil Acidity and Liming
a. Definition and expression of soil
acidity
b.
Sources of Soil Acidity
c. Types of Soil acidity (active versus
exchangeable)
d.
Percent base saturation concept
e. Soil acidity and Soil management
f. Reasons soils become acid
g.
Chemical reactions of lime in
soil
h.
Factors affecting lime reaction in
soil
i. Liming materials
j. Soil salinity
8 Soil organisms and organic matter
a. Soil Organisms (types, functions,
processes such as nitrification,
ammonification, N-fixation)
b.
Organic
matter
(definition,
composition
of
plants,
decomposition)
c. C: N ratio of materials returned to
soil
d.
Compost
Ass 30%
Exam 70%
1 Brady, N.C. 1990 the nature and
properties of soils
2 Brady, N.C., and Raymond, R.C1996.
The nature and properties of soils.
3 White, R.E. 1999. Principles ands
Practices of Soil science
4 Hussein, J 1998. Applied soil science
Module 1: soil, its formation and
properties
5 Bridges, E.M 1979. World Soils
6 Forth, H.D. 1984. Fundamentals of Soil
Science
7 Hartemink. A.2003. Reader- Introduction
Soil Science
NB. See online notes E learning account