PROPERTIES AND IDENTIFICATION OF FERTILIZERS

Characteristics Nitrogenous Fertilizers

• Highly soluble in water.
• Highly mobile in the soil hence it is applied as a top dress.
• Easily leached because of the high solubility hence does not have residual effect on the soil.
• Has scorching effect on young crops during wet seasons.
• Easy to volatilize during hot season.
• They have a tendency to cake under moist conditions.
• They are hygroscopic hence should be stored in dry conditions.

Examples:

Sulphate of Ammonia (NH4) 2 SO4-

Physical appearance:

• white crystals,
• Has acidic effect,
• Contains 20% N.

Ammonium Sulphate Nitrate [(NH4), SO4+ NH4 NO;]

Colour: granules which appear yellow orange,

• Less acidic,
• Contains 26% N.

 

Calcium Ammonium Nitrate (CAN)

Colour: greyish granules,

Neutral in nature, contains 21 % N.

Urea

Colour: small whitish granules

Easily leached or volatilized,

Contains 45- 46%N.

 

Phosphate Fertilizers

• Has low solubility and immobile.
• Non-scorching.
• Has a high residual effect hence benefit the next season’s crop.
• Easy to store because they are not hygroscopic.

Examples;

Single super-phosphate

• Appearance: whitish, creamy white granules,
• Contains 20-21 % P, O5

 

Double super-phosphate

Appearance: dark greyish granules,

Contains 40-42% P205

Triple super-phosphate

Appearance: small greyish granules,

Contain 44-48% P205

 

Potassic Fertilizers

Characteristics:

• Has moderate scorching effect.
• Moderately soluble in water.
• Most Kenyan soils have sufficient potassium.

Examples;

Marinate of Potash (KCI)

• Contain 60 – 62% K10
• Slightly hygroscopic.
• Appearance amorphous white.

Sulphate of Potash (50% K10)

Compound or Mixed Fertilizers

These are fertilizers which supply 2 or more of the macronutrients.

Examples;

• Mono ammonium phosphate.
• Di-ammonium phosphate
• 20:20:20, 23:23:23

Advantages of application of compound fertilizers

• Saves time and money.
• Mixture gives improved storage properties and better handling.

Disadvantages of compound fertilizers application

• Mixing may not be thorough.
• Incompatibility of the individual fertilizers.

 

See also

Classes of food

How to raise livestock

Dirty environment and starvation

Cares for young animals

Healthy growth for animals