NPK Fertilizers



This type of fertilizer usually is available to the public in a white, crystalline, organic form. It is a highly concentrated nitrogenous fertilizer and fairly hygroscopic. This also means that this fertilizer can be quite difficult to apply. Urea is also produced in granular or pellet forms and is coated with a non-hygroscopic inert material. It is highly soluble in water and therefore, subject to rapid leaching. It is, however, quick-acting and produces quick results. When applied to the soil, its nitrogen is rapidly changed into ammonia. Similar to ammonium nitrate, urea supplies nothing but nitrogen and the application of Urea as fertilizer can be done at sowing time or as a top-dressing, but should not be allowed to come into contact with the seed.


PRODUCT NAME UREA 46% granular
Nitrogen 46% by weight minimum
Moisture 0.5% max fisher / 0.3% max dryer
Biuret 1% maximum, by weight
Free ammonia 50 px, ppm ma
Granulation 2-4 MM 90% MINIMUM

Melting point 132A0C
COLOUR Standard white or pure white
Purity Pure, Free from harmful substance
Radiation Certified non-radioactive


Sodium Nitrates

Sodium Nitrates are also known as Chilates or Chilean nitrate. The Nitrogen contained in Sodium Nitrate is refined and amounts to 16%. This means that the Nitrogen is immediately available to plants and as such is a valuable source of Nitrogen in a type of fertilizer. When one makes a soil amendment using Sodium Nitrates as a type of fertilizer in the garden, it is usually as a top – and side-dressing. Particularly when nursing young plants and garden vegetables. In soil that is acidic Sodium Nitrate is quite useful as a type of fertilizer. However, the excess use of Sodium Nitrate may cause deflocculation.

Ammonium Sulphate

This fertilizer type comes in a white crystalline salt form, containing 20 to 21% ammonia cal nitrogen. It is easy to handle and it stores well under dry conditions. However, during the rainy season, it sometimes, forms lumps. (TIP: When these lumps do occur you should grind them down to a powered form before use.) Though this fertilizer type is soluble in water, its nitrogen is not readily lost in drainage, because the ammonium ion is retained by the soil particles. A note of caution: Ammonium sulphate may have an acid effect on garden soil. Over time, the long-continued use of this type of fertilizer will increase sol acidity and thus lower the yield. (TIP: It is advisable to use this fertilizer type together with bulky organic manures to safeguard against the ill effects of continued application of ammonium sulphate).

The application of Ammonium sulphate fertilizer can be done before sowing, at sowing time, or even as a top-dressing to the growing crop. Do however take care NOT to apply it along with, or too close to, the seed, because in concentrated form it affects send germination very adversely.

Ammonium Nitrate

This fertilizer type also comes in white crystalline salts. Ammonium Nitrate salts contains 33 to 35% nitrogen, of which half is nitrate nitrogen and the other half in the ammonium form. As part of the ammonium form, this type of fertilizer cannot be easily leached from the soil. This fertilizer is quick-acting, but highly hygroscopic thus making it unfit for storage. (TIP: Coagulation and Granulation of this fertilizer can be combated with a light coating of the granules with oil). On a note of caution: Ammonium Nitrate also has an acid effect on the soil, in addition this type of fertilizer can be explosive under certain conditions, and, should thus be handled with care.

‘Nitro Chalk’ is the trade name of a product formed by mixing ammonium nitrate with about 40% lime-stone or dolomite. This fertilizer is granulated, non-hazardous and less hygroscopic. The lime content of this fertilizer type makes it useful for application to acidic garden soils.

Ammonium Sulphate Nitrate

This fertilizer type is available as a mixture of ammonium nitrate and ammonium sulphate and is recognizable as a white crystal or as dirty-white granules. This fertilizer contains 26% nitrogen, three-fourths ojf it in the ammoniac form and the remainder (i.e.6.5%) as nitrate nitrogen. Ammonium Sulphate Nitrate is non-explosive; readily soluble in nd is very quick-acting. Because this type of fertilizer keeps well, it is very useful for all crops. Though it can also render garden soil acidic, the acidifying effects is only one-half of that of ammonium sulphate on garden soil. Application of this fertilizer type can be done before sowing, at sowing time or as a top-dressing, but it should not be applied along the seed.

Ammonium Choloride

This fertilizer type comes in a white crystalline compound, which contains a good physical condition and 26%T ammoniac nitrogen, in general, Ammonium Chloride is similar to ammonium sulphate in action. (TIP: Do not use this type of fertilizer on crops such as tomatoes because the chorine may harm your crop).

Organic Nitrogenous Fertilizers

Organic Nitrogenous fertilizer is the type of fertilizer that includes plant and animal by-products. These by products can be anything from oil cakes, to fish manure and even to dried blood. The Nitrogen available in organic nitrogenous retypes first has to be converted before the plants can use it. This conversion occurs through bacterial action and is thus a slow process. The upside of this situation is that the supply of available nitrogen lasts so much longer SND the amounts of this type of fertilizer may contain small amounts of organic stimulants that contain other minor elements that might also be needed by the plants that are being fertilized. Furthermore, they may also small amounts of organic stimulants that they may contain, or of some of the minor elements needed by plant. Oil-cakes contain not only nitrogen but also some phosphoric and potash, besides a large quantity of organic matter. This type of fertilizer is used in conjunction with quicker-acting chemical fertilizers.

Then there is also blood meal which contains 10 to 12% highly available Nitrogen as well as 1 to 2% Phosphoric acid. Blood meal, used in much the same way as oilcakes, makes for a quick remedy and can effectively be used on all types of soil as a type of fertilizer.

Fish meal which can be dried fish, fish-meal or even powder is extracted in areas where fish oil is extracted. The resulting residue is used as a fertilizer type. Obviously depending on the type of fish used. The available Nitrogen can be between 5 and 8% and the Phosphoric content can be from 4 to 6%. Fish meal also constitutes a fast-acting fertilizer type which is suitable for moslt soil types and crops. (TIP: In powder form it is at the leat.)

Muriate of Potash

Muriate of potash is a gray crystal type of fertilizer that consists of 50 to 60% potash. All the potash in this fertilizer type is readily available to plants because it is highly soluble in water. Even so, it does not leach away deep into the soil since the potash is absorbed on the colloidal surfaces. (TIP: Apply muriate of potash at sowing time or prior to sowing.)

Sulphate of Potash

Sulphate of potash is a fertilizer type manufactured when potassium chloride is treated with magnesium sulphate. It dissolves readily in water and can be applied to the garden soil at any time up to sowing. Some gardeners prefer using sulphate of potash over muriate of potash.

  • Complete inorganic fertilizers: – these types of fertilizer are formulated especially to target certain plant’s requirements or certain soil deficiencies. Of the examples that come to mind here are the Blue Hydrangea Food, and straight fertilizer that is made up of one particular plant nutrient for example lawn fertilizer.
  • Liquid fertilizers: – these types of fertilizer come in a variety of formulations and even include organic fertilizer, complete fertilizer. Some examples of liquid fertilizer are Nitro sol and African Violet Food.
  • Slow-release fertilizer: – these types of fertilizer are formulated to release their nitrogen at a steady pace. On the packs of this fertilizer that are available commercially it will usually be depicted as 3:1:5 (SR) where the SR indicates slow-release.
  • Fertilizer with insecticide: – these types of fertilizer that are prepared and combined with an insecticide. One such example is Wonder 4:1:1(21) – Karbaspray.