1. Primary Nutrients Next

2. While the others are usually found in sufficient quantities in most soils and no soil amendments are usually used. Introduction Nitrogen (N), Phosphorous (P) and Potassium (K) are often referred to as primary nutrients. They are most common elements found in commercial fertilizers. The above three essential nutrients are frequently managed by the addition of fertilizers to soils. Primary nutrients are usually lacking in soil because plants use them in large amounts for their growth and survival. Primary nutrients

3. Nutrient Deficiency Primary nutrients Nutrient Toxicity A nutrient deficiency occurs when the nutrient is not in sufficient quantity to meet the needs of the growing plant. Nutrient toxicity occurs when a plant nutrient is in excess and decreases plant growth or quality.

4. Types of deficiency symptoms (NPK) Chlorosis – yellowing of plant tissue due to limitations on chlorophyll synthesis. Necrosis - death of plant tissue sometimes in spots. Accumulation of anthocynanin - resulting in a purple or reddish color. Lack of new growth- the development of new leaf reduced. Stunting or reduced growth - new growth continues but it is stunted or reduced compared to normal plants. Primary nutrients

5. Brief key to deficiency symptoms of Primary Nutrients Symptoms Deficiency of Nutrients Symptoms appearing first on older leaves: Chlorosis starting from leaf tipN Reddish colour on green leaves or stem P Necrosis on leaf margins K Primary nutrients

6. Role of nitrogen (N) in plants Primary nutrients It is a part of all living cells and a necessary part of all proteins, enzymes and chlorophyll, etc. It helps plants with rapid growth, increasing seed and fruit production and improving the quality of leaf and forage crops. Nitrogen often comes from fertilizer application (mainly urea) and from the air (legumes get their N from the atmosphere, water or rainfall contributes very little nitrogen)

7. Nitrogen (N) deficiency in maize Chlorosis (yellowing) at the tip of the oldest leaf. Chlorosis continues to the next oldest leaf Primary nutrients

8. Role of phosphorus (P) in plants Primary nutrients It is involved in the formation of all oils, sugars, starches, etc. Helps with the transformation of solar energy into chemical energy; proper plant maturation; withstanding stress. Helps in rapid growth, encourages blooming and root growth. Phosphorus often comes from fertilizers, bone meal, and rock phosphate.

9. Primary nutrients Phosphorous (P) deficiency in maize Purple coloration of lower leaves

10. Role of potassium (K) in plants Primary nutrients Potassium is removed by plants in larger amounts than any other mineral element except nitrogen. It helps in the building of proteins, photosynthesis, fruit quality and reduction of diseases. Potassium is supplied to plants by soil minerals, organic materials, and fertilizers.

11. Potassium (K) deficiency in maize Chlorosis at the tip of the oldest leaf progressing toward the base along the leaf margins Primary nutrients

12. Forms of primary nutrients for plant uptake Nitrogen – NH 4 +, NO 3 - Phosphorus – H 2 PO 4 -, HPO 4 — Potassium – K + Primary nutrients

13. Sources of primary nutrients Primary nutrients Organic manures: Farmyard manure, green manure, composts, vermicompost, crop residues, oilcakes Chemical fertilizers: Urea (N), DAP (NP), SSP (P), Muriate of Potash (K) and potassium sulphate (K) Biofertilizers: Azotobacter, Rhizobium (N)

14. Sources of primary nutrients Vermicompost Farmyard manure Bacteria N 2 fixation Rhizobium,Bradyrhizobium with legumes Primary nutrients

15. Urea (Source of Nitrogen) MOP (Source of Potassium) Chemical fertilizers Primary nutrients

16. Let us sum up Primary nutrients can be supplied through different organic sources, chemical fertilizers and bio-fertilizers. Nitrogen, phosphorus and potassium are considered as primary nutrients. Knowledge of the properties and functions of these nutrients is helpful for their efficient and proper management. These nutrients are needed by plants in higher quantities and, thus, essential for good plant growth and high yields. Plants exhibit many shades of greenness (chlorosis) or other deficiency symptoms in case of insufficient supply. End Primary nutrients