Know the nutrient. Understand the difference.

Common examples

• Urea
• CAN (calcium ammonium nitrate)
• Ammonium sulphate
• Calcium nitrate

Crop context

Commonly used in wheat, rice, maize, cotton, sugarcane, vegetables, fodder and many fruit crops. The appropriate source and programme depend on the crop and field.

Common examples

DAP

Diammonium phosphate

MAP

Monoammonium phosphate

SSP

Single superphosphate

TSP

Triple superphosphate

Establishment matters

Phosphorus is particularly important during crop establishment. Manage it according to soil-test requirements and locally recommended agronomic practices.

Two common sources

MOP

Muriate of potash; a chloride-containing potassium source.

SOP

Sulphate of potash; may be preferred for chloride-sensitive crops.

Choose for the field

Select the potassium source according to the crop, soil and agronomic requirements, including chloride sensitivity and irrigation-water conditions.

Example label analyses

• 15-15-15
• 16-16-16
• 19-19-19
• 20-20-20
• 13-13-21
• 12-12-17
• Other crop-specific formulations

Read the product, not just the numbers

The numbers indicate the product's guaranteed nutrient analysis, not an application dose. Products may be granular, water-soluble, crystalline or liquid. Check the label for the declared nutrients and suitable application method.

Nutrient roles

Sulfur (S)

Protein formation and enzyme activity.

Calcium (Ca)

Cell walls, cell structure, plant structure and fruit quality.

Magnesium (Mg)

A central component of chlorophyll, important for photosynthesis.

Common sources

• Gypsum
• Magnesium sulphate
• Calcium nitrate
• Ammonium sulphate
• Other formulated products

Growth and reproduction

Zinc

Enzyme activity and plant growth.

Boron

Flowering, reproductive growth and cell development.

Iron

Chlorophyll formation and plant metabolism.

Metabolism and photosynthesis

Manganese

Photosynthesis and enzyme activity.

Copper

Plant metabolism and reproductive development.

Molybdenum

Nitrogen metabolism.

Common nutrient products

• Water-soluble NPK
• Potassium nitrate
• Calcium nitrate
• Potassium sulphate
• Magnesium sulphate

Targeted formulations

• Zinc formulations
• Boron formulations
• Iron formulations
• Specialty nutrient formulations

Manures and composts

• Farmyard manure
• Compost
• Vermicompost
• Poultry manure
• Green manure

Other organic materials

• Press mud
• Neem cake
• Mustard cake
• Other properly processed organic materials

Examples of microbial products

• Rhizobium
• Azotobacter
• Azospirillum
• Phosphate-solubilizing microorganisms
• Mycorrhizal products
• Other microbial formulations, subject to applicable registration requirements

What affects effectiveness

• The microorganism and crop
• Soil conditions
• Product quality
• Storage conditions
• Correct application

Before the test

Ask the testing laboratory or local agriculture authority how to collect a representative sample. Record the crop and variety, previous crop, soil type, irrigation method and field history.

Turn results into a decision

Interpret results alongside irrigation-water quality, growth stage, expected yield, nutrient deficiencies, weather and environmental conditions. Use plant or leaf analysis when appropriate, especially when assessing orchard nutrition.

Observe before applying

Record which plants and areas are affected, the growth stage and recent field conditions. Discuss possible nutrient and non-nutrient causes with a qualified agricultural professional.

Confirm the need

Use soil/plant analysis or reliable agronomic diagnosis to identify a deficiency. Apply micronutrients only where justified and review the whole nutrient balance rather than adding products indiscriminately.

Soil-based methods

Soil application

Application to soil using a method appropriate to the product and crop.

Broadcasting

Distributing fertilizer over the soil surface.

Band placement

Placing fertilizer in a defined band; placement must follow crop-specific professional guidance and the label.

Water and leaf-based methods

Fertigation

Delivering suitable nutrient products through irrigation water.

Foliar application

Applying a product intended for foliar use to plant leaves.

Check the water and system

Review irrigation-water quality, crop and soil requirements, the irrigation method and the selected product's suitability for that equipment.

Check the product and mixture

Follow manufacturer instructions for concentration, application and compatibility. Confirm compatibility with the actual irrigation water and every other product in the planned mixture before use.

Confirm suitability

Use only products labelled for foliar application to the intended crop. Review the crop's growth stage and environmental conditions against label instructions and local advice.

Plan the application

Follow the manufacturer's recommended concentration, application method and compatibility warnings. Confirm whether the proposed application addresses an identified crop need.

Field suitability

• Soil salinity and pH
• Crop chloride sensitivity
• Irrigation-water quality
• Growth stage and other field conditions

Mixture suitability

Check every product label and obtain manufacturer or qualified agronomic advice before mixing. Follow any required compatibility procedure. Do not mix products merely because they contain nutrients the crop needs.

Store according to the label

• Keep products in their original labelled packaging.
• Follow product-specific temperature, moisture, ventilation and separation requirements.
• Keep products secure and away from children, animals, food and feed.
• Observe microbial-product storage and shelf-life instructions; storage affects effectiveness.

Handle responsibly

• Follow the label and safety data sheet, including required protective equipment.
• Avoid contamination of soil and water during handling, mixing and application.
• Follow manufacturer instructions and local regulations for spills, unused material and packaging.