Soil Dryness Determination


In use from 2016-10-27


Gravimetric soil moisture calculations are taken from the difference in the wet and dry weights of a given soil sample. The oven temperature used to achieve dry soil is important. Soil samples were dried at 50, 60 and 105 Celsius and reweighed daily to determine dryness.


• Soil corer or Geoprobe, depending on desired sampling depth
• 4mm soil sieve
• Tin containers, of known weight
• Balance
• Oven with thermometer

1. Collect soil samples to desired depth.
2. Sieve soil through 4mm screen.
3. Weigh fresh soil into tin containers. Record soil weight.
4. Place open tins of soil into oven at 50C.
5. After at least 24 hours, remove the tins from the oven and allow them to cool to room temperature. Record the weight of each sample. Replace samples into the oven. Continue to reweigh the tins daily until they are no longer losing moisture.
6. Increase oven temperature to 60C and repeat step 5.
7. Increase oven temperature to 105C and repeat step 5.