Everything Science Grade 12

5.4 CHAPTER 5. THE CHEMICAL INDUSTRY

5.4 The Fertiliser Industry ESCCL

The value of nutrients ESCCM

Nutrients are very important for life to exist. An essential nutrient is any chemical

element that is neededfor a plant to be able togrow from a seed and complete its life

cycle. The same is truefor animals. A macronutrient is one that is requiredin large

quantities by the plantor animal, while a micronutrient is one that only needsto be

present in small amounts for a plant or an animal to function properly.

DEFINITION: Nutrient

A nutrient is a substance that is used in an organism’s metabolism or

physiology and which must be taken in from theenvironment.

In plants, the macronutrients include carbon (C), hydrogen (H), oxygen(O), nitrogen

(N), phosphorus (P) andpotassium (K). The source of each of these nutrients for plants,

and their function, is summarised in table 5.1.Examples of micronutrients in plants

include iron, chlorine, copper and zinc.

Table 5.1: The source and function of the macronutrients in plants

Nutrient Source Function

Carbon Carbon dioxide in the

air

Component of organic

molecules such as carbo-

hydrates, lipids and proteins

Hydrogen Water from the soil Component of organic

molecules

Oxygen Water from the soil Component of organic

molecules

Nitrogen Nitrogen compounds in

the soil

Part of plant proteins and

chlorophyll. Also boosts plant

growth.

Phosphorus Phosphates in the soil Needed for photosynthesis,

blooming and root growth

Potassium Soil Building proteins, part of

chlorophyll and reduces

diseases in plants

Animals need similar nutrients in order to survive. However since animals cannot pho-

tosynthesise, they rely on plants to supply themwith the nutrients they need. Think of