Soft Rock Phosphate

R27 - R590


Our organically certified Soft Rock Phosphate, also known as rock dust, is a slow release organic phosphate amendment that will, reduce the number of pests in your garden, increase your yield, as well as improve the flavour of your harvest.

This substance is known to reduce nitrogen loss, as well as control odour that occurs as a result of using organic fertilizers such as manure or fish emulsion extracts.

Rock Phosphate is generally used in the long run in obtaining healthy living soil(what your microbes slowly feed on), it also raises the natural levels of phosphorus and calcium which will reward you with large, resinous flowers.


Additional Information

Over the years, sedimentation from cold mineral rich fish waters along the West Coast of the Cape has formed valuable deposits which became further enriched by fossil marine and terrestrial animals who contributed threefold to that unique, now shallowly covered phosphate occurrence as it is mined today.

Altogether 300 different species of prehistoric animals and a number of plants have been identified so far. The result is a nutrient and mineral rich organic fertilizer that is low cost and extremely effective - try it out and see how much it benefits your living soil!


Key elements of rock phosphate


The total phosphorus content amounts to 8-10% P - expressed as tri-calcium phosphate - 63% of the product is in this form. By repeated extraction all of it is soluble in 2% citric acid. As an indication of the immediately available fraction, the first extraction dissolves 5% P.


This rock phosphate contains 20% calcium. Because of the linkage of phosphorus with calcium, its neutralising effect increases by the amount of phosphorus that becomes available and is taken up. The remaining calcium is in the form of carbonates and silicates.


With the exception of cobalt (Co) which is more important to animals, Langfos provides essential iron (Fe), sulphur (S), magnesium (Mg), molybdenum (Mo) and zinc (Zn). 



  • Slow release product which releases the phosphate to the plants over many years assisting the farmer to build up healthy living soil.
  • It enriches the soil with trace elements and stimulates root growth.
  • Helps with photosynthesis in all plants.
  • Cost-effective
  • Organic and tested regularly
  • Organic Registered No. B4038  Fertilizer Group 2 – Act 36 of 1947



STANDARD ANALYSIS     5% P   % m / m
Total Phosphorus (P) 8-10
(Krumm/Wagner Method - slow release)    
Calcium (Ca) 20.1
Sulphur (S) 0.145
Magnesium (Mg) 1.30
Iron (Fe) 0.73
    mg / kg
Manganese (Mn) 9
Copper (Cu) 3
Zinc (Zn) 13
Molybdenum (Mo) <10
Boron (B) 0.8
Fluoride (F) 0.76

How to use

Soil Amendment:

  • 30L of growing medium: Use 1-2 cups (240ml-480ml).
  • Per 1L of growing medium: Mix 2 heaped teaspoons (12ml).

    Grow beds: 

    • Use at a rate of approximately ½ cup 120ml per 1m². Spread rock phosphate evenly over the entire area. Mix well with soil before seeding or planting.


    • Use approximately 5kg per cubic meter (m³) of raw material.
    Do not use more than 2% of the total volume of your growing medium.

      1L (approx. 1.8kg)

      Helpful tip:

      You can speed up the release of phosphorus by combining the rock phosphate with a beneficial fungi called Mycorrhizal Fungi. The fungi help to break down and release phosphorus, making it more bio-available to the plant's roots.

      Can be fed to your earth worm beds for a significant increase in the phosphate content of the wormcastings. 


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