3. Water & Environmental / 7. FAQ's and Knowledgebase / Flame photometer

How can I determine the amount of available potassium in soils?

Soil is a mix of organic matter, minerals, air, liquids and other organisms. It is vital in supporting life on Earth by allowing plant growth as well as storing, supplying and purifying water. As rocks break down into particles of sand, silt and clay mineral particles are released and they are then available to support plant life. It is important to determine the amount of potassium naturally available in the soil to measure if and how much potassium may need to be added artificially via fertilisers.


Potassium is extracted from air-dried soil samples by shaking with 0.5M ammonium acetate/acetic acid solution for 30 minutes. This effectively displaces the potentially available K+ ions. The potassium content of the filtered extract is then determined using a Jenway PFP7 Flame Photometer.
Jenway PFP7

For more information on how to carry out this specific test or are interested in purchasing a flame photometer please get in contact with one of our technical team by phone on 01954 233 120, email support@camlab.co.uk or fill in the form below: