Topics: Soil, Pedology, Soil horizon Pages: 40 (10291 words) Published: March 12, 2013





SOS 518
2 Units
Three hours per week

Course Coordinator:
Office Location:
Other Lecturers:

Dr. Bola A. Senjobi. B.Sc, M.Sc. PhD
Room 236, COLPLANT
Dr. G. A. Ajiboye

Basic principles of soil classification. Soil morphological characteristics and classification. Soil forming minerals and rocks. Soil survey methodology. Assemblage of maps; use of aerial photographs and topographic maps for soil survey and classification. Type of soil survey, field mapping and soil sampling. Routine laboratory determinations and correlation of soil data. Soil survey report writing and interpretations. Concepts, principles and justification of land-use planning. Historical and present trends in land use. Management problems relating to tropical soils; land –use and soil degradation. Soil and land capability classification.

Compulsory course

Fitzpatrick, E. A. (1980). Soils. Longman Group Limited, London. 352pp Young, A. (1980). Tropical soils and Soil Survey. Cambridge University Press, New York.

Why classify Soil?
 To organize our knowledge about soils
 To deal with complexity
 To develop principles and guidelines for proper use and management: a. to predict behavior
b. to identify best uses
c. to estimate productivity
d. to identify potential problems

To facilitate easier transfer of information and technology
To provide a basis for research and experimentation
To understand relationships among individuals of the population To provide an organizational chart or map o f the world of soils as we perceive it - the soil survey

Basic principles of classification
 Classification is the grouping of objects into classes or groups on the basis of similarities or differences in their common properties.
 Individual objects make up a population.
 A class is a group of individual or other classes similar in selected properties and distinguished from all other classes of the same population by differences in these properties.
 In any system of classification, those groups about which the greatest number of things can be stated for the chosen objective are generally the best and the most useful classification groupings.

Key concepts of classification
• Types of objects
 Individuals
 Populations
 Sub-populations (strata)
• Issues regarding classes
 Existence of modal (‘typical’) individuals
 Measures of similarity in state space
 Measures of compactness of classes
• Types of characteristics
 Differentiating: used to defined classes
 Accessory: consistently associated with a class;
 co-variant with differentiating characteristics
Accidental: not associated with the classes
Attributes of a good differentiating characteristics
 Is important for the objective of classification
 Carry the greatest possible co-varying or accessory characteristics that are also important for the objective of classification.

Modal Individual

Principles of differentiation as they affect classes
 A differentiating characteristic must be important for the objective.  A differentiating characteristic must be a property of the things classified or a direct interpretation for the objective.

 The differentiating characteristics should carry as many accessory properties as possible for the objective.
 The class interval of a differentiating characteristic must provide classes homogenous for the objective.
Principles of differentiation as they affect relationship among categories  Differentiating characteristics must classify all individuals in any single population (Nikiforrof principle of wholeness of taxonomic categories).  Greatly different “kingdoms” require different differentiating characteristics at...
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