SOS 2101 SOIL PHYSICS AND CHEMISTRY
Course Instructors:
Moses M. Tenywa (Bsc Agric. Msc Agric; PhD) Full time staff;
Lukman Mulumba (BSc Agric; MSc Agric; PhD) Full time staff
Mr. Sam Ssessanga (BSc Agric; MSc Soil Science); Full time staff
John Stephen Tenywa (BSc Agric. MSc Agric, PhD); Full time staff
Peter Ebanyat BSc Agric; MSc (Soil Science), PhD). Full time staff
CORE (B.Sc. Agric. II, BSc Forestry II)
Course Credits (CU): 3 CU i.e. 45 Contact Hours per semester
Prerequisite: Introductory Soil Science
Course description:
Soil physical properties; their influence on air, workability, compaction, pore size and distribution. Water flow
processes (infiltration, percolation, redistribution and evapotraspiration). Soil water content and potentials. Saturated
and unsaturated water flow. Temperature, thermal regimes and heat flow in soils. Soil temperature management.
The soil chemistry part of this course deals with the solid phase particularly the clay mineralogy in relation to soil
chemical properties; solid - aqueous phase interactions; the double layer theories and their implications on nutrient
availability; ion exchange (cation and anion exchange capacities) and their measurements; chemical reactions in
soils and influencing factors; surface chemistry including P sorption isotherms; the chemistry of acid soils and their
management including determination of lime requirements; the chemistry of hydromorphic soils and their
management; halomorphic soils, types and methods of evaluation -Electrical conductivity, ESP SAR and their
management.
Objectives
The goal of this course is to deepen students’ knowledge in the areas of soil physics and chemistry and how they
influence soil fertility.
Specific objectives of the course include;
(i)
To build students knowledge of soil physical and chemical properties and processes and how they influence
on nutrient availability
(ii)
To equip students with knowledge and skills for assessment of soil physical and chemical properties.
Key references
Hillel D. (1980) Fundamentals of Soil Physics, Academic Press Inc. Landon Ltd.
Hillel D. (1980) Applications for Soil physics, Academic Press Inc. London Ltd.
Bohn H.L., McNeal B.L., O’Connor, G.A (1985), Soil Chemistry. John Wiley and Sons, Inc. New York.
Sparks, D. L.(1995). Environmental Soil Chemistry., Academic Press, New York
Sposito, G (1989). The Chemistry of Soils. Oxford University Press, New York.
OURSE CONTENT, METHODS OF INSTRUCTION, TOOLS AND EQUIPMENT REQUIRED
Week
Topic
The Soil and soil
physics
Recap what soil is, its components and
its formation, Parents materials and soil
physical characteristics; Definition of soil
physics; importance of soil physics
Instruction approach/ time
allocation
Interactive Lecture (2 hrs)
Inputs required
Overhead/
Soil physical properties
Soil structure
Soil Density and
Soil compaction
Texture and its importance and influence
on other soil phases; the air and water
phases and influencing factors (mass
volume relationships); The pore space
and distribution concepts; Infiltration and
Water holding capacity; Soil drainage; soil
consistency
Interactive lecture (2 hrs)
Definition and importance of soil structure
; process of formation; types of soil
structure; influence on soil physical
chemical and biological processes;
methods of assessment (The Flocculation
Index, dry and wet sieving methods);
tillage and structure management; tillage
equipment and tillage frequency
Interactive lecture ( 2 hrs)
Overhead
projector, chalk
Laboratory practical (3 hrs):
Evaluation of soil structure
using dry and wet sieving
methods
Sieves …..
Definitions of Bulk density and Particle
Density and their determination;
influencing factors
The concept of soil compaction and
causative factors; remedial measures
Interactive lecture
Field practical to assess compaction and
remediation machinery and equipment
The field water cycle
and water flow in soils
Soil Temperature
Practices of Soil
temperature
moderation
The hydrological cycle; The SPAC
concept and
Processes; The soil water potentials;
Saturated water flow;
Gaseous /vapour flow of
Water; Unsaturated flow of water
The soil moisture characteristic cure; field
capacity, field Capacity,
Permanent wilting points and the
water availability to plants.
Energy aspects of soil temperature
and influence on soil activities and overall
productivity ( the Q10 concept); Heat flow
processes; thermal conductivity of soils;
soil temperature variations; thermal
regimes of soils’ profiles and soil
Field practical (3 hrs): Field
determination of water
infiltration
Practical to see different
machinery and equipment
that can be used to correct
compact at university farm
(3 hrs)
Interactive lecture (2 hrs)
Overhead/projec
tor
Double ring
infiltrometers
Overhead projector/
Practical (3 hrs)
Pressure plate
and soil samples
of varying
texture
Interactive
lecture
Overhead
projector /
Practical (3 hrs): Field
practical to measure soil
temperature management
Assessment
Examination
Introduction to soil
chemistry
Solid phase and charge
development
Solid –aqueius
interaction
Surface Chemistry
Soil Acidity
Hydromorphic soils
Continuous assessment (Soil physics)
Examination (1 hr)
Definition of Soil Chemistry; Evolution from
plant production focus to environment
management
Interactive lecture (1 hr)
Clay mineralogy and influence on soil
chemical properties
Charge development (permanent and pH
dependent charge) and zeta potentials;
Cation and double layer theories and
influence on nutrient availability
anion exchange (specific and non specific
adsorption); influencing factors
Heavy metals
Assessment and review
Overhead
projector
Laboratory practical (3 hrs):
Laboratory determination of
CEC
Chemicals ; filter
paper; soil
samples and
glass ware
Overhead
projector; chalk
Laboratory determination of P Isotherms
Laboratory practicals (3 hrs)
Soil reaction and measurements; Causes
and chemistry of soil acidity, impacts on
nutrient availability, management of acid
soils including liming
Interactive lecture (2 hrs)
What they are; categories, chemistry of
the various categories; evaluation of the
salinity (TDS, EC, ESP, SAR), effects of
salts on plants
Chemistry of heavy metals and their
effects on water quality; methods of
assessment of
Continuous assessment
Overhead
projector
Interactive lecture (2 hrs)
Interactive Lectures (2 hrs)
What they are and their chemistry,
problems resulting from their drainage;
management
???
Interactive Lecture (2 hrs)
Sorption Isotherms (Langmuir, Freundlich
and BET) and implications on nutrient
availability – example of P. Types of
isotherms
Laboratory determination of LR
Halomorphic soils
temperature variations on a
landscape in MUARIK
Laboratory practical (3 hrs):
Laboratory determination of
exchangeable and total
acidity
Interactive Lecture (2 hrs)
Laboratory Practical (3 hrs)
Interactive lectures (2 hrs)
Soil samples;
chemicals
Overhead
projector; chalk
Chemicals; soil
samples,
Overhead
projector
Soil samples,
chemicals
Overhead
projector; chalk
Laboratory practical (3 hrs):
Laboratory determinations of
EC
Soil samples,
EC meter
Interactive Lectures (2 hrs)
Examination (1 hr)
General review of topics
Revision
Examination
Discussion and question and Chalk
answer session (1 hr)
Student revision
Final examination and course evaluation
Interactive lectures covering theory
Laboratory and field-based practicals
30 hrs
15 hrs
Grading
Two continuous assessment exams
10 practical reports
Final examination
Total
20%
20%
60%
100%
Examination and overall
course evaluation (3 hrs)