NPK Measurement in Soil Samples

The NPK Meter allows growers to test Nitrate, Phosphate and Potassium (NPK Measurement) in minutes with one probe and just 50ml of sample solution.

This accurate, instant test means is simple to operate and avoids the need to send samples to the test laboratory with all of the cost and delay that causes so much frustration.

The meter is calibrated with one Multi-Cal Standard solution and displays all three parameter results in ppm on the screen. This result can be stored in the internal memory and downloaded to Excel for storage and manipulation.

It is not possible to place the NPK Sonde directly in soil to achieve a result;

Sample preparation for Soil testing.:

1. Air dry soil samples, crush and pass through a 2mm sieve.

2. Add 100ml of NPK ISAB* Solution to a 50g soil sample.

3. Shake for 30 sec, stand for 15 mins and shake again for 5 sec. Repeat this shaking procedure three times. Allow soil to settle.

4. Extract 50ml of the supernatant sample from the top of the beaker into the Measuring Cylinder provided.

This is your sample.

Method

The sample can now be treated in the same way as any NPK test so follow the steps in the video below.

Don’t forget to double the result as the Nutrients are now in 100g of solution rather than 50g of soil.

The NPK meter kit can also be used for monitoring Run-off from Coir bags in Polytunnels, River water and other environmental applications

To measure the NPK in soils there is a sample preparation step to get an aqueous sample. The NPK can be directly determined to establish soil health and calculate the Fertilizer Kg/Hectare requirement. Depending on the accuracy required the soil sample should be taken and air dried to ensure a consistent weight is being analysed. For further advice email [email protected]