Monthly Archives

February 2018

SULPHUR SOURCES

By | Micro Nutrients, Sulphur Products | No Comments

Sulphur (S) is one of the secondary macro nutrients that has often been forgotten or neglected in planning a fertilizer program. The general “rule of thumb” was that crops required the same amount of S as they do phosphorus. Prior to the advent of high grade phosphates which form the back bone of todays NPK bulk blends  the S requirement of crop was supplied through NPK  compound containing AMS, single super phosphate, enriched super phosphate and ammoniated super phosphates such as AMP(16), and atmospheric S from industrial SO2 emissions. Alternative sources of S are found in Potassium Sulphate, ASN and Ammonium Sulphate. The cheapest source of S is from gypsum. Disclaimer: The figures published are not a guarantee of analysis, they are sourced from published Product Data Sheets and provided to serve as an indicator of typical analysis which may vary due to production processes, impurities and changes in minerology of natural sources. Please note: Consult a qualified person (Act 36 of 1947) for specific applications / recommendations.

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Potassium Nitrate

PROPERTIES OF POTASSIUM NITRATE

By | Potassium Products | No Comments

All figures quoted should be considered as a typical product analysis and may vary due to manufacturing process and raw materials. PHYSICAL PROPERTIES A granular crystal or fine crystalline white powder. Critical Relative Humidity @ 30ºC: 90.5. Solubility @ 20ºC: 47 g/100ml of water (31% concentration). Water quality is critical in determining solubility, in some areas advisors recommend  25g /100ml water (20% concentration) to ensure solubility. CHEMICAL PROPERTIES Chemical formula: KNO3. 38% Potassium (K). 13% Nitrogen (N). Salt index: 74 (relative to Sodium Nitrate at 100). Acidification index: non acidifying AGRONOMIC BENEFITS Suitable for crops that are sensitive to chloride. Technical grade product should preferentially be used for foliar feeding and drip irrigation. Compatible for blending with MAP, LAN, Urea, Ammonium Sulphate ,Potassium Chloride. Please note: Consult a qualified person (Act 36 of 1947) for specific applications / recommendations.

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Triple Super Phosphate - TSP also referred to as Double Super

PROPERTIES OF TRIPLE SUPERPHOSPHATE – TSP

By | FERTILIZER PRODUCTS, Phosphate products | No Comments

All figures quoted should be considered as a typical product analysis and may vary due to manufacturing process and raw materials. PHYSICAL PROPERTIES A generally spherical shaped granular product. Colour generally light to dark grey. Critical Relative Humidity @ 30ºC: 75 – 85. CHEMICAL PROPERTIES A mono calcium phosphate. Chemical formula: Ca(H2PO4)2 . H2O. 19 – 23% Phosphorus (P). Over 90% of the P in TSP is water soluble. 15.5 – 17.1% Calcium (Ca). 1 – 2.3% Sulphur (S). Salt index: 10.1 (relative to Sodium Nitrate @ 100) AGRONOMIC BENEFITS TSP provides  the highest concentration of straight phosphate fertilizer that is available. Provides a P source for production of  blends for leguminous crops where no additional nitrogen is desired. Granules dissolve rapidly in the soil in the presence of adequate soil moisture. Compatible for blending with LAN, Potassium Chloride, Potassium Sulphate, Potassium Nitrate.   Please note: Consult a qualified person (Act 36 of 1947) for specific applications / recommendations.

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FERTILIZER GRADES AND NUTRIENT CONCENTRATIONS IN RSA AND SADC COUNTRIES

By | FERTILIZER PRODUCTS, NPK Products | No Comments

All fertilizer products sold in South Africa must be registered in terms of the Fertilizers, Farm Feeds, Agricultural Remedies and Stock Remedies Act, 1947 (Act 36 of 1947) and are sold with a specific registered plant nutrient concentration which is printed on the fertilizer packaging. The South African fertilizer industry manufactures a broad range of fertilizer products as compounds or mixtures which contain two or more of the Primary Macro plant nutrients Nitrogen (N), Phosphorus (P) and Potassium (K) which are broadly referred to as NPK products. In South Africa NPK products are named using a numerical system e.g. 4:3:4(33) which is called the “grade” of the product. The grade of a product is also a guarantee of analysis for that specific product; the tolerance on nutrient concentration variances in a product are regulated by Act 36 of 1947. The grade 4:3:4(33)  contains the primary macro nutrients in a ratio of 4 parts N : 3 parts P : 4 parts K, the sum of which totals 11 parts.The total plant food concentration is displayed in brackets, in this example 33%.  The NPK concentrations can be calculated from the grade accordingly: The concentration of N: 4⁄11 X 33 = 12% The concentration of P: 3/11 X 33 = 9% The concentration of K: 4⁄11 X 33 = 12% The total nutrient concentration of NPK adds up to 33% as displayed in brackets. The other 67% of the product consists of the elements Ca, H, O, S, Cl and a few other elements which are constituents of the raw material compounds and filler material. Other Secondary Macro Nutrients such as Sulphur (S) and micro nutrients such as Zinc (Zn) may also be registered as plant food ingredients in NPK products; their concentrations are expressed as a percentage and included in the grade notation of the product, e.g.: 4:3:4(33)+0.5%Zn or 4:3:4(33) +2% S +0.5%Zn. In some SADC countries, Europe and America fertilizer grades are expressed differently, where all the numbers in the grade refer to percentages of plant nutrient however the P and K content are expressed as oxides: Total N is as % N Total P is as % P2O5 Total K is as % K20 To convert P2O5 to % P multiply by 0.4364 (conversely divide by 2.2915) To convert K2O to % K multiply by 0.8302 (conversely divide by 1.2046) For example the Zambian product with the grading 8: 24: 16 would contain elemental nutrient concentrations equating to: N: 8% P: 24 X 0.4364 = 10.47% K: 16 X 0.8302 = 13.28% Please note: Consult a qualified person (Act 36 of 1947) for specific applications / recommendations.

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Potassium Sulphate - SOP

PROPERTIES OF POTASSIUM SULPHATE – SOP

By | FERTILIZER PRODUCTS, Potassium Products, Sulphur Products | No Comments

All figures quoted should be considered as a typical product analysis and may vary due to manufacturing process and raw materials. PHYSICAL PROPERTIES A granular crystal or fine white crystalline powder. Critical Relative Humidity: 96.3. Solubility @ 20°C: 11.1 g/100ml of water. CHEMICAL PROPERTIES Chemical formula: K2SO4. 42% Potassium (K). 17% Sulphur (S). Salt index: 46 (relative to Sodium Nitrate @ 100). AGRONOMIC BENEFITS Suitable for crops that are sensitive to chloride. Technical grade product should preferentially be used for foliar feeding and drip irrigation. Compatible for blending with Mono Ammonium Phosphate, LAN, Urea, Ammonium Sulphate, Potassium Chloride. Please note: Consult a qualified person (Act 36 of 1947) for specific applications / recommendations.

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Mono Ammonium Phosphate(33) - MAP(33)

PROPERTIES OF MONO AMMONIUM PHOSPHATE – MAP

By | FERTILIZER PRODUCTS, Phosphate products | No Comments

All figures quoted should be considered as a typical product analysis and may vary due to manufacturing process and raw materials. PHYSICAL PROPERTIES A generally spherical shaped granular product. Colour may vary from cream /white – yellow brown – grey. Critical Relative Humidity: 91.6. Solubility @ 20°C: 32.8 g/100ml of water (37.4, technical grade). CHEMICAL PROPERTIES Chemical formula: NH4H2PO4. 22% Phosphorus (P), technical grade 27% P. 11% Nitrogen (N), technical grade 12% N. Salt index: 26.9 (relative to Sodium Nitrate @ 100) AGRONOMIC BENEFITS Dissolves rapidly in the soil in the presence of adequate soil moisture. Pure sources are suitable for foliar feeding and drip irrigation. Compatible for blending with LAN, Urea, Ammonium Sulphate, Potassium Chloride, Potassium Sulphate, Potassium Nitrate. Please note: Consult a qualified person (Act 36 of 1947) for specific applications / recommendations.

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Potassium Chloride - KCl - MOP

PROPERTIES OF POTASSIUM CHLORIDE – KCl – MOP

By | FERTILIZER PRODUCTS, Potassium Products | No Comments

All figures quoted should be considered as a typical product analysis and may vary due to manufacturing process and impurities. PHYSICAL PROPERTIES A fine or granular product. Colour of product may vary from white – pink – red and grey depending on minerology and impurities. Critical Relative Humidity @ 30°C: 84. Solubility at 20°C: 34.2g / 100ml water CHEMICAL PROPERTIES Chemical formula: KCl. 50% Potassium (K). 50% Chloride (Cl). Salt index: 114 (relative to Sodium Nitrate @ 100). AGRONOMIC BENEFITS & CAUTIONS 1. The cheapest and most concentrated source of K. 2. May be put through irrigation systems. 2. NPK plant mixtures that have been band placed and contain combined  Nitrogen and Potassium content in excess of 75kg could cause salt burn. 5. Compatible for blending with MAP, LAN, Urea, Ammonium Sulphate. Please note: Consult a qualified person (Act 36 of 1947) for specific applications / recommendations.  

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Granular Urea(46)

PROPERTIES OF UREA

By | FERTILIZER PRODUCTS, Nitrogen Products | No Comments

All figures quoted should be considered as a typical product analysis and may vary. PHYSICAL PROPERTIES  A white granular / prilled product. Particle size distribution of granular product typically ranges from 2.0 – 5.0mm. Critical Relative Humidity @ 30°C: 72.5% Solubility at 20°C: 108g / 100ml of water. CHEMICAL PROPERTIES 46% Nitrogen (N). NH2-CO-NH2 N in the Ammine (NH2) form and is not available for plant uptake. NH2 is converted to NH4+ through the urease reaction. Acidification index: 3.57 kg pure lime/kg N or 1.64 kg pure lime per kg urea applied. Salt index: 75 (relative to Sodium Nitrate @ 100). Biuret (NH2-CO-NH-CO-NH2) may be formed by polymerization at high production temperatures. AGRONOMIC BENEFITS & CAUTIONS Urea is the most widely used N source in agriculture. It is the cheapest source of N and due to its higher concentration additional savings may be made on application and logistics costs. Urea is readily soluble and may be put through irrigation systems. Urea N is not immediately available for plant uptake. NH2 must first be converted to ammonium before it can be taken up by plants. Ammonium doesn’t leach due to its positive charge. Urea in solution carries no electrical charge and is prone to leaching. Leached urea will lead to sub soil acidification and eutrophication of dams and rivers. Urea is best washed into the soil through rainfall or irrigation or incorporated to prevent volatilization losses. Application of urea to a soil surface covered with plant residue could increase volatilization due to urease in the plant residue. Avoid application of urea to recently limed soil surfaces as the alkalinity from the lime could cause volatilization. Urea is compatible for blending with Mono Ammonium Phosphate, Ammonium Nitrate and Potassium Chloride. Avoid mixing urea with nitrates or nitrate containing mixtures to prevent NPK blend quality problems. Biuret levels >1.5% may lead to toxicity especially when foliar feeding. Although feed grade urea is used in animal feeds as source of non-protein nitrogen, caution should be taken to prevent spillages and contamination with drinking water as excess urea is toxic and will cause in mortality in livestock. Please note: Consult a qualified person (Act 36 of 1947) for specific applications / recommendations.

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