PRINCIPLES OF SOIL SCIENCE.pdf

Description

Study Units
The following are the study units contained in this course. The units are
arranged into four identifiable but related modules.
Module 1 The Soil Habitat

Unit 1 Some Basic Concepts of Soil
This unit takes you through the definitions of some soil basic
terminologies, composition of the soil and its importance to man.
Unit 2 Origin and Development of Soil (Soil Genesis)
The second unit of this course deals with different types of rock which
serve as parent materials from which soils are formed. You will also
learn about the different factors and processes that form soil and give
the soil its different characteristics.
Unit 3 Fundamental Concepts of Soil Physics
This unit serves to acquaint the student with the physical nature of
different soils such as types and stability of aggregates, compaction and
porosity.

Unit 4 Soil Classification and Survey
You will be exposed to those observable and reasonable characteristics
used for soil classification. Similarly, land survey as prerequisite to
classification will be explained.
Unit 5 Plant Growth Requirements
This unit caps module one of this course. You will be exposed to the
factors that contribute to the growth and general performance of field
crops including the concept of “principle of limiting factor” in crop
production.
Module 2 Processes in the Soil Environment
Unit 1 Water in the Soil-Plant System
This unit discusses the gains and losses of water in the soil-plant system,
effect of well-and poorly-drained soils and the management of soil
water for efficient use by crops.
Unit 2 Soil Aeration and Temperature
You will learn about how redox potential (i.e. oxidation – reduction
potential) in soil affects availability of plant nutrients and that plants
strive well under optimum soil temperatures.
Unit 3 Soil Organic Matter and Soil Organisms
In Module 2 unit 3, you will learn about the importance of maintaining
organic matter especially in Nigerian agriculture, the reasons for low
organic matter content in our soils and the roles played by organisms in
the transformation of soil organic matter.
Unit 4 Soil Reaction: Acidity and Alkalinity
You will learn in this unit soil acidity and conditions that make soils
acidic, conditions in acid soils which are beneficial or detrimental to the
growth of plants, effects on plants of neutral and alkaline soils and lime
and liming practices.
Unit 5 Soil Colloids and Ion Exchange in Soils
This unit exposes you to one of the most important interactions between
the solid phase and the solution phase of the soil. Cation exchange

reactions and cation exchange capacity as peculiar to each soil type have
implications in plant nutrition.
Module 3 Soil-Plant Nutrients Interaction
Unit 1 Fertilizers as Agricultural Input
In unit 1, different types of fertilizer materials, fertilizer formulations
and economic use of fertilizers are discussed with practical example in
contemporary Nigerian agriculture. You will also learn about fertilizer
specifications and calculations.
Unit 2 Nitrogen as Plant Nutrient
As the most important and most limiting nutrient element throughout the
world particularly in the tropics, this unit describes the various forms
and functions of nitrogen in plants, nitrogen-cycle, inputs and losses of

nitrogen to the soil-plant system and the factors that affect these N-
transformations in the soil-plant ecosystem. You will also be able to

detect N-deficient symptoms in crops.

Unit 3 Phosphorus Nutrition in Plants
Like unit 2, this unit will enable you to be conversant with forms and
functions of phosphorus in soil and plants, the peculiar characteristic
problem of p-recovery especially in acid and alkaline soils, the various
indices of phosphorus availability and the detection of p-deficiency
syndromes in field crops.
Unit 4 Potassium Nutrition in Plants
As the third most limiting major plant nutrient element, potassium
demand by crops especially root crops is high. You should learn about
potassium cycling problems both in agricultural and forestry systems.
Unit 5 Sulphur, Calcium and Magnesium
You will know in this unit that though sulphur (S), calcium (Ca) and
magnesium (Mg) are referred to as secondary nutrients, they must be
supplied from fertilizer sources for optimum crop performance. There
are factors affecting their functions in crops and availability in soils.
Module 4 Soil Fertility Evaluation and Management

This unit offers have a good knowledge of the different methods of
evaluating the fertility status of a piece of cropland. It also enables you
to differentiate between soil analysis and soil testing. You will also learn
the procedures in carrying out soil testing programmes.
Unit 1 Micronutrients Elements
This unit will describes the general characteristics common to all
micronutrients, the effect of soil factors on their deficiency and toxicity
in soils and their specific functions in agricultural and forestry crops.
Unit 2 Soil Analysis and Soil Testing
This is Unit offer a good knowledge of the differ.rent methods of
evaluating the fertility status of a piece of crop land. It also enables you
to differentiate between soil analysis and soil testing. You will also learn
the procedures of carrying out soil testing programmes
Unit 3 Principles and Practice of Plant Analysis
This unit explains the techniques of using plant analysis as a diagnostic
tool for detecting nutrient deficient symptoms in crops as well as a
reliable guide in making fertilizer recommendation to crop farmers. This
unit also includes growth response terminologies and the general
limitations of using plant analysis to make predictions on crop response
to nutrient supply.
Unit 4 Soil Salinity and Alkalinity
This unit exposes you to the causes and effect of salinity, sodicity and

alkalinity. Compared to the easy control of nutrient deficiencies, salt-
related constraints are more costly to remedy. Management of salt-
related factors limiting plant growth will be described.

Unit 5 Soil and Water Conservation
You will be able to discuss land clearing, land tillage, agronomic and
cultural farming practices in your locality that help to conserve soil and
water on crop farms. How do we avert pollution in the biosphere and
atmospheric environment? The Federal, State, Local Governments and
individuals have roles to play here.