Chapter 5: Fertilizer – A Source of Plant Nutrients

Fertilizer = Any material containing one or more of the essential nutrient that is added to the soil or to plant foilage for the purpose of supplementing the plant nutrient supply.

Types of Fertilizer

Simple Nutrient – Containing only a single nutrient.

Multi-Nutrient – Referred to as mixed or complex fertilizers. (can be blended or homogeneous)

Anhydrous Ammonia

NH3

82-0-0Is combined with

hydrogenVery energy intensiveAmmonia is

absorbed readilyInjected in soil

Aqua Ammonia

NH4OH20-0-0Dissolved in waterVapor pressure is

low so can apply it with lower cost equipment

Injected in soil or water

Ammonia Nitrate

NH4NO3

34-0-0Reacting nitric

acid with anhydrous ammonia

Prilled granulated or coated

Applied by broadcast or drill

Ammonia Nitrate - Lime

26-0-0Contains Calcium

Carbonate (40% limestone)

Same ways to apply as Ammonia Nitrate

Ammonium Sulfate

(NH4)2SO4

21-0-0-24SContains 24% sulfurMade by reacting

anhydrous ammonia with sulfuric acid

Apply by drill or broadcast

Calcium Nitrate

5Ca(NO3)2 +NH4NO3

15.5-0-0-19 CaProduct of Nitric

phosphate+phosphate ore and ammonia

Final product is white granular product

Nitrogen Solutions

Dry mixes in solution are used to enhance nitrogen availability

AN-20 Ammonia NitrateUAN-32 urea ammonium

nitrateCAN-17 Calcium nitrate

ammonium nitrateSalting out

Urea

CO(NH2)2 46-0-0Highest percent N of

all dry fertilizersCO2 bubbled in

Ammonia (pressure and temperatures)

Highly water solubleUsed in bulk blends

Nitrogen Solutions

Pressure or non pressure – Pressure solutions have more free ammonia than the solution can absorb, thus it must be contained in vessel.

AN-20, UAN-32,and CAN 17

Single Superphosphate

Ca(H2PO4)2 . H20 + CaSO4 . 2H20

0-20-0Produced by reacting sulfuric acid with

finely ground phosphate rock.Highly insoluble

Triple Superphosphate

Ca(H2PO4)2 . H20

0-45-0Produced by reacting phosphoric acid

with finely ground phosphate rock.

Ammonium Phosphate

Monoammonium phosphate (MAP) 11-52-0Diammonium Phosphate (DAP) 18-46-0Ammonium Phosphate Sulfate 16-20-0-15(S)Tech – higher grades of MAP & DAP,

12-61-0 and 21-53-0.Liquid forms – 8-24-0, 9-30-0, 10-34-0, &

11-37-0

Potassium Chloride

KCL0-0-60Known as Muriate of potash (MOP)Least expensive so most commonly used.

Potassium Sulfate

K2SO4

0-0-52Sulfate of Potash (SOP)Used in crops that are subject to chloride

toxicity or where K & S are deficient.

Mono Potassium Phosphate

KH2PO4

0-52-34MKPUseful dry or liquid

Potassium Magnesium Sulfate

K2SO4 . 2MgSO4

0-0-22-11Mg- 22SDoes not contain chloride

Potassium Nitrate

KNO3

13-0-45Water soluble fertilizer for injection in

irrigation systems & foliar sprays.

Organic Fertilizers

Types?

Controlled Released Fertilizers

Why?