III. Fertilizers: Utilization and Types

Introduction

World demand for increased food, feed, and fiber production necessitates us of fertilizers.

                                 

Fertilizers

Fertilizers are materials occurring naturally or commercially produced for application to soil for the purpose of adding one or more deficient nutrients

Fertilizers

Research says that optimum ferts use increase yields world wide by 50%

Fertilizer History

Farmers used ferts lavishly before 1974.After 74, fuel and energy cost

skyrocketed!Farmers needed more money, so they

selected soil and crops that used ferts the best.

But bottom line, fert does not cost, it pay!

Fertilizer Trends and Economics

Dry bagged fert use decreased with the increase use of dry-mix and liquid fert.

Fertilizer Trends and Economics

Ferts cost represent about 20% of all crop productions

Producers expect a corresponding increase in yield of 50%

This is a return of two to three dollars for every dollar spent

Fert is Profitable When:

1. Based on a soil test2. Added in an

efficient manner3. Soil is managed

Fert is Unprofitable When:

1. Soil moisture is limited

2. Pest and adverse temps are a problem

3. Increased yield has less market value than cost of ferts.

Fertilizer Efficiency

Point of Diminishing Return

Point at which cost of applying additional fert is unprofitable in terms of increased production

Determining Fertilizer Needs

Amount and Type depends on:– 1. Amount removed by previous crop– 2. Amount lost by leaching and other

processes– 3. Amount and type of nutrients available in

soil– 4. Climatic conditons– 5. Requirements of present crop– 6. Crop quality desired

Determining Fertilizer Needs

Just do a soil test analysis! Idiot!

Types of Ferts.

1. Organic Derived from plant and

animal material

2. Inorganic Contains no C, H, and

O’s

Forms of Fertilizer Materials

1. Dry-MixMade by combining selected elements into a bulk blendcomes in a granular form

2. LiquidMaterial completely dissolved in solutionMay contain a single nutrient or mixture

3. GaseousAnhydrous ammonia

Numbers on the Bag

Types of Fertilizers

Nitrogen– N

Phosphorus– P

Potassium– K

Fert Grade and Quality Control

Label must contain:– Weight of material– Manufacturer’s name– Manufacturer’s address

Fert Grade and Quality Control

Example: 10-20-10Contains 10% Nitrogen, 20% P2O5,

and 10% K2060% of the product is conditioners

(to reduce caking), acidity neutralizers (Lime), fillers (extender added to improve uniform distribution of nutrients

Nitrogen Ferts

Material

1. Ammonium nitrate

2. Ammonium sulfate

3. Anhydrous ammonia

4. Aqua ammonia

5. Organic products

6. Urea

Nitrogen Content (N%)

33.5%

20 – 21 %

82%

20-24%

1-12%

45-46%

1. Ammonium Nitrate

NH4NO3

50% is ammonium form and the remainder is in nitrate form.

The two allow nitrogen to be used immediately

2. Ammonium sulfate

(NH4)2SO4

High in costBest forms of N for rice crops

3. Anhydrous ammonia

NH3, is the principle nitrogen fert.

Applied by injection into moist soil behind tractor at about 6 inches deep.

Made from atmospheric nitrogen and natural gas in Texas plants.

4. Aqua ammonia

NH3 + H20

A low pressure nitrogen fert, applied three inches below soil surface.

5. Organic products

Sludge, Manure, Meat Meal, Cottonseed Meal, and fish meal.

6. Urea

A controlled release fert.Formed by coating granular urea with

sulfur, then wax, then clay.

Phosphorus Ferts.

Material

1. Basic Slag

2. Bone Phosphate

3. Rock Phosphate

4. Superphosphate, ordinary

5. Superphosphate, triple

Multiple P% by 2.29137 to obtain P2O5% equivalent.

Phosphorus Content (P%)

3.5 – 5.2

10-13

13-17

9

20-22

1. Basic Slag

Low-phosphorous by-product of iron and steel mills

Used mainly in areas where produced

2. Bone phosphate

Steamed bone mealOldest known phosphate fertilizer

3. Rock phosphate

Mainly from Florida

4&5. Superphosphate

Rock phosphate mixed with sulfuric acid = superphosphate

Rock phosphate mixed with phosphoric acid = triple superphosphate

Potassium Ferts

Material1. Muriate of potash2. Sulfate of potash3. Sulfate of potash

magnesia4. Potassium nitrate5. Potassium

polyphosphate

Multiply K% by 1.20459 to obtain K2O% equivalent

Potassium Content (K%)

42-50

37-42

15-18

31-37

17-33

Ferts supplying other nutrients

Lime

Sulfur

Boron

Molybdenum

Iron

Zinc

Magnesium

The End