Nutrition in Plants – Mineral Nutrition

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Nutrition in Plants – Mineral Nutrition- essential minerals for plant growth

MODULE - 2
Forms and Function of Plants and Animals

9
Notes

NUTRITION IN PLANTS – MINERAL NUTRITION
Sometimes you may observe that a potted plant kept in sunlight and provided with sufficient water does not grow. Its leaves look pale and weak. Plant may not even flower properly. Such a situation is an indication, that the plant may not be getting all that is required for normal growth and development. In most of such situations one or more minerals required may be lacking in the soil you might have seen farmers adding some extra manure (khad) to the soil. In this lesson you will learn the importance of mineral nutrition in plants.

OBJECTIVES After completing this lesson, you will be able to : define the terms mineral nutrition, macro and micro nutritients; explain the functions of minerals with reference to the techniques of hydroponics and aeroponics; list the role of macro and micro nutrients; mention the deficiency symptoms of macro and micro nutrients; differentiate between autotrophic and heterotrophic nutrition in plant; describe the saprophytic and parasitic modes of nutrition in plant. 9.1 WHAT IS PLANT NUTRITION As you know that all living organisms require food to survive, grow and reproduce so every organism takes in food and utilizes the food constituents for its requirements of growth. A series of processes are involved in the synthesis of food by plants, breaking down the food into simpler substances and utilization of these simpler substances for life processes. Nutrition in plants may thus be defined as a process of synthesis of food, its breakdown and utilisation for various functions in the body. BIOLOGY

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MODULE - 2
Forms and Function of Plants and Animals

Nutrition in Plants – Mineral Nutrition

Notes

The chemical substances in food are called nutrients e.g. CO2, water, minerals, carbohydrate, protein, fats etc. Green plants can make their own food from simple substances like water and carbon dioxide through the process of photosynthesis and are called autotrophs (auto : self; trophos : feeding). But the non-green plants and other organisms which cannot prepare their own food and obtain nutrition from green plants are called heterotrophs (heteros : different). 9.2 MINERAL NUTRITION Now we will discuss how plant get the nutrients. You already know that carbohydrates are synthesised by the process of photosynthesis. What are the elements present in these carbohydrates? Carbon, hydrogen and oxygen are the main elements in carbohydrates, fats and proteins. In addition to these three elements, plants need a variety of elements for their survival. These are generally referred to as mineral elements. They are absorbed by the root system of plants in the form of their salts. The study of how plants get mineral elements and utilize them for their growth and development is called mineral nutrition. If the minerals are not available to plants, specific symptoms appear due to the deficiency of a particular element. There are methods to determine the requirement of minerals by plants. Some such method are given below. 9.3 METHODS TO DETERMINE THE REQUIREMENT OF MINERAL FOR PLANT Minerals are absorbed by plants in solution form. So it is possible to grow plants in water containing the desired amount of mineral salts taking care that the aerial parts are exposed to air and light. This technique of growing plants in a nutrient solution in complete absence of soil is known as Hydroponics/water culture. It was demonstrated for the first time by a German Botanist Julius Von Sachs in the year 1980. In water culture experiments, seedlings are made to grow in water containing the known nutrients in a particular proportion. Vigorous bubbling of the air is routinely done to provide sufficient oxygen to the root system. The culture solutions may contain all essential nutrients except the one whose importance is to be...
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