1. C arbon-Hydrogen-Oxygen-Nitrogen-Phosphorus-Potassium

2. Nutrients  Macronutrients  Needed in larger quantities  Micronutrients  Needed in smaller quantities

3. Non-Fertilizer Nutrients  Cannot be supplied in a fertilizer  Come from Water & Air (H2O & CO2)  Carbon  Hydrogen  Oxygen

4. Primary Macronutrients  Nitrogen  Phosphorus  Potassium  Complete fertilizer must contain all 3

5. Secondary Macronutrients  Calcium  Magnesium  Sulfur

6. Nitrogen  Encourages Growth  Gives plants a dark green color Deficiency: - Plant turns lighter green - Yellowing leaves - Slow growth

7. Phosphorus  Root Development  Encourages Flowering  Improves Winter Hardiness  Deficiency  Purplish coloration to leaves  Stunted Growth

8. Potassium  Increases disease resistance  Thickens cell walls  Aids in the transport of food in the phloem  Deficiency  Yellowing, death of tissue at the tips.

9. For Proper Fertilizer Application

10. Calculating Pounds of Fertilizer  A bag of fertilizer has 3 numbers on it.  N-P-K  10-15-20  Weight of Bag X % of Nutrients = Lbs. of Nutrient in the bag.

11. Practice Problem  10% Nitrogen- 15% Phosphorus-10% Potassium  The bag weighs 50lbs.  How many pounds of Nitrogen are in this bag of fertilizer? 50 x.10= 5lbs. Nitrogen

12. Try it on you own: Problem #1  You purchased a bag 33 pound bag of 25-5-15 vegetable fertilizer for your garden this summer. If you wanted to re-create this fertilizer for next year, how many pounds of nitrogen, phosphorous and potassium would you need?

13. Answers  Nitrogen: 0.25*33lbs.= 8.25 lbs.  Phosphorous: 0.05*33lbs.= 1.65 lbs.  Potassium: 0.15*33lbs.= 4.95 lbs.

14. Try it on your own: Problem #2  You are mixing a fertilizer for your flower garden. You ended up with 50 pounds of fertilizer. The fertilizer contains 5 pounds of nitrogen, 5 pounds of phosphorous and 15 pounds of potassium. You want to patent your product, but you need to include the ‘three numbers’.  What percentage of the fertilizer is nitrogen? Phosphorous? Potassium?

15. Answer  Nitrogen: 5 lbs./50 lbs.= 0.10 = 10%  Phosphorous: 5 lbs./50 lbs. = 0.10 =10%  Potassium: 15 lbs./50 lbs. = 0.30 = 30%