SOS 7103 SOIL ORGANIC MATTER
Lecturers
Dr. Twaha Ali Basamba (B.Sc. For., PG Dip. Soil Survey, M.Sc. N.R.M.., Cert. Pedagogy,
Cert. Data Analysis, Cert. Gender, Cert. Computer Skills, PhD (Env. Sci))
Assoc. Prof. Victor Ochwoh (B. Sc. Agric, M.Sc. Agric, PhD (Soil Science))
Course Type:
CORE (M.Sc. Soil Science)
Course Credits (CU):
3 CU i.e. 45 Contact Hours per semester
Course Duration: 15 weeks (45 hours) i.e. 30 LH, 30 PH
1. COURSE DESCRIPTION
Chemical and physical nature of soil organic matter (SOM). Formation of humus. Role of micro-organisms in SOM
decomposition. Soil organic matter and soil productivity. Organic matter turn-over. Influence of cropping systems, and
management (liming, pesticides, manure and fertilisers) on humus status, formation and degradation. Carbon
sequestration in terrestrial ecosystems.
2. COURSE OBJECTIVES
The overall objective of this course is to enable students understand the principles, processes and practical aspects
related to soil organic matter and its management in cropping systems
The specific objectives are:
i)
ii)
iii)
To facilitate knowledge and skill development on soil organic matter contribution to land productivity
To make students competent in soil organic matter management for sustainable agricultural productivity
To enhance student capacity to carry out soil organic matter research
3. SUGGESTED READING LIST
1. Brady, N.C. and Weil, R.R. 1996. The nature and properties of soils. Prentice-Hall, Inc. London. 881p.
2. Paustian, K., Parton, W.J. and Persson, J. 1992. Modelling soil organic matter-amended and nitrogenfertilized long-term plots. Soil Science Society American Journal 56: 476-488
3. Basamba, T.A., Barrios, E., Ameziquita, E., Rao, I.M. and Singh, B. R. 2006. Tillage effects on maize yield
in a Colombian savanna oxisol: Soil organic matter and P fractions. Soil and Tillage Research 91: 131-142.
4. Monreal, C.M. and Janzen, H.H. 1993. Soil organic carbon dynamics after 80 years of cropping a dark
brown chernozem. Canadian Journal of Soil Science 73:133-136
5. Kononova, M.M., Nawakowski, T.Z. and Greenwood, G.A. 1961. Soil organic matter-its nature, its role in soil
formation and in soil fertility. Pergamon Press. New York. 450p.
6. Woomer, P.L., Martin, A., Albrecht, A., Resck, D. and Scharpenseel, H.W. 1994. The importance and
management of soil organic matter in the tropics. Pages 47-80. In: P.L. Woomer and M.J. Swift (eds.), The
Biological Management of Soil Fertility. J. Wiley and Sons, Chichester.
4. COURSE CONTENT, METHODS OF INSTRUCTION, TOOLS AND EQUIPMENT REQUIRED
TOPIC/WEEK
CONTENT
METHOD OF
INSTRUCTION /
TOOLS /
EQUIPMENT
1. INTRODUCTION
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2. STRUCTURE OF
SOIL ORGANIC
MATTER
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3. PROPERTIES OF
SOIL ORGANIC
MATTER
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4. FUNCTIONS OF
SOIL ORGANIC
MATTER
5. FORMATION OF
SOIL ORGANIC
MATTER AND
HUMUS
6. COMPOSITION OF
SOIL ORGANIC
MATTER




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
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7. ROLE OF MICROORGANISMS IN SOIL
ORGANIC MATTER
DECOMPOSITION



8. SOIL ORGANIC
MATTER AND SOIL
PRODUCTIVITY





9. ORGANIC MATTER
TURN- OVER

Concept of soil organic matter
Soil organic matter and humus
History of soil organic matter research
Soil organic matter and agricultural
development
The dimmer structural concept
Atomic bonding in the dimmer structure
Implications of the dimmer structure to
soil organic matter characteristics
Morphological properties
Physical properties
Chemical properties
Biological properties
Nutrient availability
Moisture regulation
Support to micro, meso and macro
fauna and flora
Erosion control
The rhizosphere environment
Theories of soil organic matter and
humus transformation
Plant, animal and microbial substrates
Enzymatic reactions
Isolation of organic matter from the
mineral portion of the soil and
associated problems
Constituents of soil organic matter,
their physical and chemical properties
Soil organic matter chemical and
physical fractionation, advantages and
disadvantages
Disintegration of organic residues in
nature and the micro-organisms
involved
Organic matter decomposition under
aerobic and anaerobic conditions
Factors that affect soil organic matter
decomposition
The C:N ratio
Nutrient release
Water retention
Labile soil organic matter and nutrient
cycling dynamics
Influence of soil organic matter on crop
yields
Influence of different land use
strategies on soil carbon storage
Time allocated
Lectures (3 hrs)
NEEDED
Chalk / Black
board or Markers /
Flip charts
Lectures (3 hrs)
Chalk / Black
board or Markers /
Flip charts
Lectures (3 hrs)
Chalk / Black
board or Markers /
Flip charts
Lectures (3 hrs)
Chalk / Black
board or Markers /
Flip charts
Lectures (3 hrs)
Chalk / Black
board or Markers /
Flip charts
Lectures (2 hrs)
Laboratory practical
(3 hrs)
Chalk / Black
board or Markers /
Flip charts/Sizedensity
fractionation
equipment and
chemicals
Lectures (3 hrs)
Chalk / Black
board or Markers /
Flip charts
Lectures (2 hrs)
Field practical (2.5
hrs)
Chalk / Black
board or Markers /
Flip charts/soil
auger/chemicals
Lectures (1 hr)
Seminar (2 hrs)
Chalk / Black
board or Markers /
Flip charts
10. CROPPING
SYSTEMS AND
FORMATION OF SOIL
ORGANIC MATTER
11. CROPPING
SYSTEMS AND
DEGRADATION OF
SOIL ORGANIC
MATTER
12. INFLUENCE OF
LAND USE ON SOIL
ORGANIC MATTER
13. CARBON
SEQUESTRATION IN
TERRESTRIAL
ECOSYSTEMS
14. SOIL ORGANIC
MATTER AND
FERTILIZER USE
15. ADVANCES IN SOIL
ORGANIC MATTER
RESEARCH
 Influence of climate change on rates of
carbon loss and build up
 Interaction between soil inorganic
constituents, microbial activity and
metabolic products
 Soil organic matter fractions under
different cropping systems
 Sensitivity of soil organic matter
changes in cropping systems
 Definition of a cropping system
 Types of cropping systems and how
they affect soil organic matter levels
(monocropping, sequential cropping,
intercropping, mixed cropping, ley
farming etc)
 Cultivation effects
 Soil carbon levels under different land
uses
 Effect of contrasting land uses on the
chemical composition of soil organic
matter
 Concept and process of carbon
sequestration
 Soil organic carbon sequestration in
wetlands, croplands, forests, mine
lands etc
 Relationship between soil organic
carbon stock and soil quality
 Soil organic carbon mapping
 Effects of mineral fertilizer use on soil
organic matter quality and quantity
 Effect of mineral fertilizers and farm
yard manure
 Physical fractionation of soil organic
matter into biologically meaningful
pools and general methodology for
extraction and characterisation of labile
soil organic matter
 Soil organic matter quality assessment
 Soil organic matter and climate change
 Evaluation
5. SUMMARY OF TIME NEEDED
Lectures covering theory
Laboratory-based practicals
Field-based practicals
30 hrs
9 hrs
5 hrs
Lectures (1 hr)
Laboratory Practical
(3 hrs)
Chalk / Black
board or Markers /
Flip
charts/chemicals
Lectures (1 hr)
Field Trip (2.5 hrs)
Chalk / Black
board or Markers /
Flip
charts/Transport
Lectures (1 hr)
Laboratory practical
(3 hrs)
Chalk / Black
board or Markers /
Flip
charts/Chemicals
Interactive lectures (2 Chalk / Black
hrs)
board or Markers /
Flip charts
Interactive lectures (1 Chalk / Black
hr)
board or Markers /
Seminars (2 hrs)
Flip charts
Interactive Lectures
(1 hr)
Seminars (2 hrs)
Tests (2 hrs)
Chalk / Black
board or Markers /
Flip charts
Seminars
Evaluation
06 hrs
02 hrs
6. OVERALL COURSE EVALUATION
Continuous Assessment Test
Field and laboratory-based practicals
Final examination
20%
20%
60%