1. Fertilizers

2. Objective 6.02
Discuss the advantages and disadvantages of various fertilizers.

3. Types of Fertilizers Complete Incomplete Organic Inorganic Soluble
Insoluble

4. Fertilizers
A fertilizer analysis label indicates the amount of Nitrogen (N), Phosphorus (P), and Potassium (K) contained as a percentage of weight
Example:
will have 10% N, 20% P, and 10% K

5. Complete Fertilizer
Complete has all three primary nutrients-nitrogen phosphorous & potassium
Examples: , ,
Advantage: plants receive all essential elements
Disadvantage: some plants may not need all essential elements

6. Incomplete Fertilizer
Incomplete DOES NOT have all three primary nutrients
Examples: , ,
Advantage: plants need a selective element
Disadvantage: plants may need more elements

7. Organic Fertilizers
Comes from plant or animal matter and contains carbon compounds
Examples: urea, sludge and animal tankage

8. Advantages of Organic
Slow release of nutrients- reduce risk of over-fertilizing
Not easily leached from the soil
Improves the water holding capacity of the soil
Improves physical condition of the soil
Adds organic components to growing media

9. Disadvantages of Organic
Has a smell and is heavy
Some are not sterile
Low nutrient content
Expensive

10. Inorganic Fertilizers
Comes from sources other than animals or plants
Chemical products

11. Advantages of Inorganic
Contains the three essential nutrients (N,P,K) in desired amounts
Fast release capability makes it readily available for plants
Easy to get as most commercial fertilizers are in an inorganic form

12. Disadvantages of Inorganic
No organic material
possible chemical building up in growing media
Leaches out in heavy rain or through irrigation
High acid concentration which leads to high soil acidity

13. Soluble Fertilizer
Dissolve in water and are applied as a liquid solution
Fertigation
fertilizing through irrigation water
big advantage

14. Insoluble Fertilizer
Includes granular and slow release applied to the growing media

15. Granular vs. Slow Release
relatively inexpensive
easy to find
Slow Release
more expensive because it is coated
more uniform release of nutrients over time period

16. 20-10-20 Fertilizer Analysis N P K
Fertilizer analysis expresses weight as a percent of nitrogen, phosphorus and potassium N P K

17. Fertilizer Analysis For Example
A 100 pound bag of fertilizer has an analysis of How many pounds of nitrogen, phosphorus and potassium are in the bag?
Nitrogen: 100lbs X 15%=15lbs
Phosphorus: 100lbs X 5%=5lbs
Potassium: 100lbs X 15%=15lbs

18. Fertilizer Ratios
A fertilizer with a analysis would have a 1:1:1 ratio
A fertilizer with a analysis would have a 3:1:2 ratio
What would be the ratio for a fertilizer with an analysis of ?
4:2:3

19. Application Procedures
Banding
Sidedressing
Topdressing
Perforating
Broadcasting
Foliar spraying
Fertigation

20. Banding
Placing a band of fertilizer about two inches to the sides and about two inches below seed depth.
DO NOT place below the seeds because fertilizer will burn the roots.
Banding is close enough to efficiently supply the young plants with nutrients, but not too close to damage developing roots

21. Sidedressing
Spreading of fertilizer between the rows and around the plants after seedlings emerge from the soil

22. Topdressing
Mixing fertilizer uniformly into the top one to two inches of growing media around the plant.

23. Perforating
Placing fertilizer in 12”-18” holes drilled 18” to 24” around the canopy drip line of fruit trees. Cover the holes and fertilizer slowly dissolves.

24. Broadcasting
Spreading fertilizer to cover the entire production area

25. Foliar Spraying
Spraying micronutrients in a solution directly on plant leaves.
Quickly corrects nutrient deficiencies
Fertilizer concentration should not be too high or leaf burning will occur.

26. Fertigation
Incorporating water-soluble fertilizer into the irrigation system of greenhouse and nursery crops.
Concentrated solutions usually pass through proportioners or injectors to dilute to the correct ratio.
Venturi-type
Positive-displacement

27. Venturi-type Simple and inexpensive less accurate
depends on water pressure in the hose and in the smaller tube to proportion
Example: Hozon

28. Positive-displacement
More expensive
very accurate
physically inject and mix specific amounts of concentrated solution and water
Examples: commander proportioners, and Smith injectors

29. Rules for applying fertilizers
Method used should be practical, effective and cost efficient
Method used affects nutrient availability for plant use
Fertilizer must be dissolved and reach plant roots