Calculating soil composition / Texture

Knowing texture/ type of your garden soil is foremost thing which you should do to maximize the chances of success. So question is - Can it be done at home without much efforts? 

Yes, you can. Follow the below steps for testing your garden soil.

1. Take sample of your garden soil. Make sure that the soil sample represents your garden soil. Or better take different samples from different garden beds / areas.

2. Take a plastic jar and fill it with soil sample till half way. 

3. Now fill three forth of the plastic jar having soil sample with water leaving some space for shaking and Close the lid tightly.

4. Shake the jar vigorously for 3-4 minutes to separate the soil particles. You can add a pint of powdered detergent to make separation of soil particles fast.

5. Leave the jar untouched for 24 hrs. Sand (Coarse soil particles) settles down at the bottom of the jar due to heaviest nature of particles. The process is completed within few minutes of shaking. Silt (lighter than sand but heavier than clay) takes few hours to settle out of the solution. It forms middle layer between sand and clay. Clay, the lightest particle in soil can take 1 to 2 days to settle out the solution. It makes top layer of finely textured soil particles and is light in color.

6. Organic matter remains suspended in solution. 

Calculation

Measure the height of each layer with a ruler and divide each layer width with total height of soil sample in the jar to calculate percentage of sand, silt and clay in soil sample. 

% sand = (Height of sandy layer (bottom) / total height of soil sample) * 100

% silt = (Height of silt layer (middle) / total height of soil sample) * 100

% clay = (Height of clay layer (top) / total height of soil sample) * 100

For example, suppose if height of sandy layer is 5 cm, silt layer is 2.5 cm and clay layer is 2.5 cm then % of each type in my soil would be -  

 

Total height of soil in jar is 5cm +2.5cm +2.5cm  = 10 cm

% sand = (5 cm/10cm *100) = 50 %

% silt = (2.5cm/ 10cm) * 100 = 25%

% clay = (2.5cm/10cm) * 100 = 25%

 So the composition of soil sample (sand, silt, clay) would be 50, 25, 25.