Question

We have identified a soil type as a fine soil in a project. Explain the additional quick methods that we can use to find if the soil is silt or clay in field.

Answer 1

Quick methods that we can use to identify if soil is silt or clay in field are-

1. The bottle test -

This test takes a bit longer but can give you a better idea about soil. For this test you need a clear transperent bottle / jar. Its a very simple test carried out in following manner-

• Put 20% of soil in a bottle and 80% fill it with water.
• Shake the jar really well for about 4-5 mins.
• Keep the bottle steady, and do not touch it for an hour.
• After the wait is complete-
  • If the water will gets cleared and the layer settled at the bottom is of silt.
  • If the water is still not clear and layer of soil is also setteled, it is because some of the finest clay particles are still mixed in the water. Then its clay.

       

2. The Soil test by Feel Method -

    This is the simplest and easiest to find out the soil characterstic. Soil test by feel method is carried out in two types by following manner-

Type 1 ( rolling ) -

• Take a handful of soil and wet it.
• Roll the soil on hand and make it snake like form.
• Hang off the snake like soil from your hand.
  • Sample with plenty of clay will stick to your hand (as shown in below fig) without forming much cracks.
  • Sample with silt will form a proper snake like without sticking much.

Type 2 ( palm ) -

• Take a small amount of the soil from sample and place it on your palm.
• Add little of water to the sample.
• With the help of your fingure rub the soil against your palm.
  • If it feels sticky then the sample is clay.
  • If it feels like touching flour, the sample is silt.

Summary- Quick methods that we can use to identify if soil is silt or clay in field are The bottle test and The Soil test by Feel Method - Type 1 ( rolling ) & Type 2 ( palm ).