Soil Chemistry and FertilityUnit 2.2 | 3
Introduction
Introduction: Soil Chemistry and Fertility
Unit Overview
This unit introduces students to the
basic concepts of soil chemistry, with
an emphasis on how soil chemistry
relates to the development and
maintenance of soil fertility.
The unit begins with a review
of basic chemistry concepts and
terminology, including atoms,
compounds, ions, and chemical
reactions. Soil nutrients essential
to plant growth and the processes
involved in nutrient uptake are then
introduced, with particular attention
paid to cation exchange capacity
and base saturation as it relates to
soil fertility. Soil pH and its effects
on nutrient availability is then
introduced.
The unit concludes with an
overview of the biogeochemical
cycles involved in making essential
nutrients available to plants;
the physiological role of
essential plant nutrients; the
characteristic symptoms of plant
nutrient deficiencies; and the soil
amendments used to supply
limiting nutrients for organic
farming systems.
MOdes Of instrUctiOn
> LeCtURe (1 LeCtURe, 3.0 hOURS)
The lecture covers basic chemistry concepts and definitions
relating to soil chemistry, in particular, nutrient uptake pro-
cesses and plant nutrients. Each plant nutrient is discussed
individually.
> DemOnStRAtIOnS
Five suggested demonstrations are designed to be integrated
into the lecture. They provide visual representations and
analogies for the concepts presented in the outline.
> ASSeSSment QUeStIOnS (1.0 hOUR)
Assessment questions reinforce key unit concepts and skills.Learning Objectives
COnCeptS
• Basic chemistry concepts (atomic structure and atomic
bonding) and terminology
• Principles and processes involved in cation exchange
• pH and its effects on nutrient availability
• Soil acidity
• Soil alkalinity
• Plant nutrients — what they are, movement in the soil,
cycling, their use in plants, and nutrient deficiency
problemsSKILLS
This material is primarily conceptual, providing back-
ground for the skill-based sessions in Part 1