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Justin Chipomho Email Phone 011 583 776

Fertilizers ď Ž

ď Ž

Fertilizers are compounds applied to plants to promoting growth. Soil or foliar applied, for uptake by plant roots or leaves.

Types of Fertilizers      

Blends (soluble or field grade) Compounds Straight fertilizers Specialty fertilizers Liquid fertilizers Others Like Gypsum and Lime

Why do we use Fertilizers 

 

To achieve high yields even in nutrient depleted soils. Improve crop quality and shelf life (Horticulture product). Supply one or more of the nutrients. Elements are readily available and easily taken up by the crops.

Why do we use Fertilizers ď Ž

ď Ž

Fertilizers are easy to handle and to apply. Only the nutrient required can be applied

Soil analysis A soil test - the best guide to the application of fertilizers. ď Ž Analysis includes for pH, fertilizer recommendations and clay content determination A representative soil sample gives an average estimate of the whole area sampled. ď Ž The best time to take samples is in June or after harvesting. ď Ž

Fertilizer Recommendations      

Type of the crop Target yield Soil analysis results Type of soil Application timing Quality of the crop

Plant Nutrients ď Ž

ď Ž

Plant nutrients can be divided into two groups. Macro elements: Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), Sulphur (S).

Plant Nutrients ‌ ď Ž

Micro elements: Zinc (Zn), Iron (Fe) Boron (B), Molybdenum (Mo), Manganese (Mn), Copper (Cu), Chlorine (Cl),

Factors to consider when choosing application method     

Type of the crop. Type of fertilizer Crop spacing Soil condition. Stage of the crop.

Methods of Application     

Broadcasting Side dressing Banding Precise application Station /Planting hoe Foliar Sprays

Methods of Application… Foliar Sprays  Done with soluble fertilizers.  Fertilizer have less salts to avoid burning leaves.  Nutrients are immediately absorbed by the crop.  Pesticides or fungicides can be mixed with some pesticides saving on time and labor. 

Methods of Application…  

  

Fertigation Fertilizer applied through the irrigation system. Most efficient practice. Applied fertilizers are. Compatible fertilizers can be mixed in the tank. A very efficient way of fertilizer application and gives good results.

Methods of Application…  

Drenching. Common method with small areas in horticulture. Fertilizer is very soluble and is mixed with water. Directly applied to the crop using watering cans.

Fertilizer Placement ď Ž


Correct placement

Fertilizer placement‌ ď Ž

Fertilizer placement

Factors Affecting Fertilizer Use Efficiency 

    

The efficient use of fertilizers entails the use of the 5R’s Right kind of material Right source, Right amount Right place Right time

Timing of Fertilizer Application  

   

Which fertilizer do I need. How much fertilizer do l need? and How do l apply it? Timing and frequency of application of fertilizers is dependent on the: Age of the Crop. The type of the Crop. The type of fertilizer material. The soil type, – choice of the applicator.

Timing of Fertilizer Application ď Ž ď Ž

ď Ž

Proper timing is important with nitrogen. Phosphate application is most efficient when applied before planting or at planting. All basal fertilizers should be applied at planting or before planting.

Complementary practices 

     

Crop management practices that need more attention include: (GAP) Selection of varieties. Planting dates. Plant populations. Planting depths. Row spacing. Pest control and – tillage methods.

Specialty fertilizers ď Ž

ď Ž

These are fertilizers which can either be applied directly to crop foliage or can be added to the soil to supply elements needed for plant nutrition. They are either soluble solids or liquids.

Other soluble specialty ferts       

Zinc oxide Solubor / ultrabor Quick start, MAP Quick grow, Murate of Potash Best bloom, Potassium Nitrate Calcium Nitrate Mag. Nitrate

Liquids    

Foliar 15 Wuxal Calcium Wuxal 3-2-1 Foliar Feed

Benefits of foliar feeding 

Foliar feeding influence flowering, fruit set, fruit size, berry size, Correct single or multiple deficiencies of nutrients. Rapid plants growth and increased returns. Enhanced absorption of soil applied nutrients.

Environmental effects of fertilizer use. 

ZFC attains ISO 14001 which is an environmental management system. Over use of fertilizers could result in more harm than good. Excessive use of nitrogen will predispose the plant to disease and pest attack due to softer cell walls present. In same case nitrogen often induces or prolong the vegetative phase of the crop.

Environmental effects of fertilizer use. 

Excess nitrogen induce Zn and Cu deficiency. Excess phosphorus will result in Zn and Cu deficiency. Nitrogen can lead to Eutrophication and can cause excessive death of aquatic organisms. It is recommended that knowledge of the nutrient content of the soil and the crop requirements be carefully balanced.


Agritex fertilizer use (by Justin Chipomho)  
Agritex fertilizer use (by Justin Chipomho)  

Excellent presentation concerning the basics of good chemical/inorganic fertilizer use.