1. Introduction
- Mineral nutrition is the study of how plants absorb and utilize nutrients.
- Plants require essential nutrients for growth, metabolism, and development.
- Deficiency of any essential nutrient can cause physiological disorders.
- Nutrients are classified into macronutrients and micronutrients.
2. Essential Nutrients
- Essential nutrients are elements required for normal plant growth and reproduction.
- There are 17 essential nutrients, divided into macronutrients and micronutrients.
(a) Macronutrients
- Required in large quantities.
- Include Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), and Sulfur (S).
(b) Micronutrients
- Required in small quantities but essential for plant growth.
- Include Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Molybdenum (Mo), Boron (B), Chlorine (Cl), and Nickel (Ni).
3. Functions of Essential Nutrients
| Nutrient | Function |
|---|---|
| Nitrogen (N) | Component of proteins, chlorophyll, and nucleic acids; promotes leaf growth. |
| Phosphorus (P) | Essential for DNA, RNA, ATP; promotes root development. |
| Potassium (K) | Regulates stomatal function, enzyme activation. |
| Calcium (Ca) | Strengthens cell walls and regulates enzyme activity. |
| Magnesium (Mg) | Main component of chlorophyll, activates enzymes. |
| Sulfur (S) | Component of amino acids, proteins. |
| Iron (Fe) | Required for chlorophyll synthesis. |
| Zinc (Zn) | Plays a role in enzyme function and hormone production. |
4. Deficiency Symptoms of Nutrients
- Nitrogen Deficiency: Yellowing of leaves (chlorosis), stunted growth.
- Phosphorus Deficiency: Purple coloration of leaves, poor root growth.
- Potassium Deficiency: Leaf curling, brown edges, weak stems.
- Calcium Deficiency: Weak cell walls, blossom-end rot in fruits.
- Magnesium Deficiency: Interveinal chlorosis (yellowing between leaf veins).
- Sulfur Deficiency: Pale young leaves, reduced protein formation.
- Iron Deficiency: Severe chlorosis, white patches on young leaves.
- Zinc Deficiency: Small leaves, shortened internodes.
5. Nutrient Absorption and Transport
- Nutrients are absorbed by root hairs from the soil.
- Transport occurs through xylem and phloem.
- Nutrients can move by diffusion, active transport, or facilitated diffusion.
6. Methods to Correct Nutrient Deficiencies
- Fertilization: Application of organic or inorganic fertilizers.
- Soil amendments: Lime for acidic soil, sulfur for alkaline soil.
- Foliar Spray: Direct spraying of nutrient solutions on leaves.
- Crop rotation: Growing nitrogen-fixing crops to maintain soil fertility.
7. Conclusion
- Essential nutrients are vital for plant growth and productivity.
- Both macronutrients and micronutrients play crucial roles in plant metabolism.
- Nutrient deficiencies can cause growth abnormalities and lower yield.
- Proper fertilization and soil management are necessary for healthy plant growth.