Page 1 - LN-CH-12

CBSE Class-11 Biology
CHAPTER-12

MINERAL
NUTRITION

Mineral nutrition is the study of source, mode of absorption, distribution and metabolism of

various inorganic substances (minerals) by plants for their growth, development, structure,

physiology and reproduction.

Methods to study the Mineral Requirement of Plants

• Hydroponics is the technique of growing plants in nutrient solution in complete
absence of soil. This method is used to determine the nutrients essential for plants.

• In this method plant is cultured in soil-free, defined mineral solution. These methods

require purified water and mineral nutrients.
• Essential elements are identified and their deficiency symptoms are discovered by

hydroponics methods. It is also used for commercial production of vegetables, like

tomato and cucumber.

Essential mineral nutrients- About 65 elements are found in different plants. Following
criteria is used to determine the essentiality of an element.

1. Element must be absolutely necessary for the normal growth and reproduction to
complete their life cycle.

2. The requirement of element must be specific and not replaceable.
3. Element must be directly involved in the metabolism of plants.

• Macronutrients are present in plants tissues in larger quantity. C, Hand O is obtained

from water and rest are absorbed from soil.

• Micronutrients or trace nutrients are required in very small quantity.

On the basis of diverse functions, essential elements are divided into following categories-

Role of Macro and Micro nutrients-

1. Essential elements participate in various metabolic processes in plants such as
permeability of cell membrane, maintenance of osmotic potential, £TS. Etc.