🌱 8.1 – Nutrition in Plants

🌟 Importance of Nutrition

Let’s start with a simple idea:
All living things, whether animals or plants, need food to live. This food gives them the energy to grow, move, repair their bodies, and stay alive. In scientific terms, we use the word nutrition to describe how living things get this food and how they use it inside their bodies.

Now, what is a nutrient?

👉 A nutrient is any substance that provides the body (whether it’s a human, animal, or plant) with the essential ingredients it needs to carry out life processes. These ingredients are used in metabolism — which means all the chemical reactions happening in a living organism to keep it alive.

🧪 Types of Nutrients

There are two broad categories of nutrients:

1. Energy-providing nutrients:
   • Carbohydrates: Like sugars and starch, used for quick energy.
   • Lipids (Fats): Used for long-term energy storage.
   • Proteins: Used for building body tissues and also sometimes for energy.
2. Supporting nutrients:
   • Water: Essential for dissolving substances and transporting them.
   • Electrolytes: Like sodium and potassium, help in electrical signals in cells.
   • Minerals and Vitamins: Help in specific roles like bone formation, immune system, and chemical reactions.

So, nutrition is the process that includes:

• Intake of nutrients,
• Their digestion or breakdown,
• Their absorption into the body,
• And finally, their use for growth, repair, and daily functions.

🌿 Macronutrients and Micronutrients in Plants

Now, let’s talk about plants.
Plants are autotrophs, which means they make their own food using sunlight, carbon dioxide, and water in a process called photosynthesis.

But apart from these basic ingredients, they also need many nutrients from the soil. These nutrients are minerals dissolved in water and absorbed by roots.

We divide these nutrients into two groups:

🅰️ A. Macronutrients

These are the nutrients that plants need in large amounts — just like how humans need a lot of carbohydrates and proteins.

There are nine macronutrients:

🧱 Carbon, Hydrogen, Oxygen, Nitrogen, Potassium, Calcium, Phosphorus, Magnesium, Sulphur

💡 Let’s understand their roles one by one:

1. Carbon (C), Hydrogen (H), and Oxygen (O)
   • These come mainly from air (CO₂) and water (H₂O).
   • Used to make organic compounds like glucose (plant sugar), which is the main food the plant produces.
   • Think of them as the basic building blocks of plant matter.
2. Nitrogen (N)
   • Helps in making proteins, enzymes, and chlorophyll (which makes leaves green).
   • Very important for growth and making new leaves and stems.
   • Deficiency symptoms: Leaves turn yellow, plants grow slowly (stunted growth).
3. Phosphorus (P)
   • Found in ATP (the energy molecule).
   • Helps in root development, flowering, and fruiting.
   • Deficiency: Delayed flowering, leaves turn brown and wrinkled.
4. Potassium (K)
   • Controls water balance in the plant.
   • Helps in the movement of nutrients inside the plant and improves photosynthesis.
   • Deficiency: Leaves develop dark patches, plant becomes weak.
5. Calcium (Ca)
   • Makes the cell walls strong.
   • Helps in growth of new cells, and seed development.
   • Deficiency: Leaves show yellow and brown spots, growth is affected.
6. Magnesium (Mg)
   • At the center of the chlorophyll molecule – vital for photosynthesis.
   • Also helps in moving phosphorus and storing sugar.
   • Deficiency: Yellowing of older leaves, brown spots, and weak stems.
7. Sulphur (S)
   • Helps in protein formation and nitrogen metabolism.
   • Deficiency: Whole plant becomes pale or light green.