QUALITATIVE SOIL TEXTURE ANALYSIS

Aim: To determine the soil texture of a soil sample using touch.

Material:

• • Sandy soil,

  • Clayey soil,

  • Silty soil,

  • Water,

  • pen,

  • pencil,

  • record book/card

Procedure:

1. Collect a sample of soil from your yard.

2. Rub each soil type between your fingers.

3. Observe and record how the soil feels.

4. Add water slowly to a handful of soil. As you do, roll the soil into a ball. If the soil becomes too wet, add more dry soil and if it becomes too wet, add more water.

5. Observe and record whether the soil is able to form a ball.

6. Roll the ball between your fingers to form a 'worm' until it breaks. Measure the length the ribbon reaches before it breaks.

7. Record your observations.

8. Excessively add water to a pinch of soil and rub it between your fingers.

9. Record whether the soil feels gritty, smooth or in between.

Observations:

Draw a table in your books using appropriate headings and include your observations under the correct headings.

Analysis:

Draw the chart below and use it to determine your soil texture.

Discussion:

1. Define soil texture.

2. How does soil particle size influence soil texture?

3. Observe the flowchart carefully and answer the questions that follow:

• Why is sand unable to form a ball when moist?

• Why is silt able to form a ball but unable to form a ribbon?

• Why are loam and clay the only soil types able to form a ribbon?

Conclusion:

1. What is your soil texture?

2. Plasticity refers to the ability of soil to be moulded into different shapes. Why does soil texture affect the plasticity of the soil?

Reference:

• NCERD. Grade 9 Crops and Soils Curriculum Guide. Ministry of Education. Guyana.

• Image of Soil Texture Qualitative Analysis Flowchart: <https://lh4.googleusercontent.com/oxBMcSDfERi3xF5zOby_bbVT1pZ1OoLYZNi1yt443WT5VILxeRV9zatTnOmKCUtr0WNemh_K80Epj4zWW2mSl4uEWc42dGhAl9crADP7MI9s00658m4=w1280>