Soil Composition

 

Soil Composition

 

Loamy soil: is made up of a mixture of different types of soil particles.  It may be important for farmers and gardeners to know the exact percentage composition of each of these particles in a sample of soil.

 

Aim: To observe the composition of sand, clay and silt particles in a sample of loamy

         soil.

 

The materials we needed:

1.     1 large test tube or measuring cylinder with stoppers/plugs or plastic wrap. 2.     Test tube rack 3.     1 sample of loam soil 4.     spatula 5.     Water 6.     Ruler 7.     Permanent marker 8.     Beakers 9.     newspaper

 

The method we used:

1. Fill a clear test tube ¼ full of the loamy soil sample. Label test tube with your group name.
2. Fill the rest of the test tube ¾ (75%) with water right up to the brim.
3. Close the container with a stopper or plastic wrap.
4. Shake contents vigorously (by placing the palm of your hand firmly over the top of the test tube) ensuring that all the soil particles are mixed.  This breaks up the soil aggregates and separates the soil into individual soil particles.
5. Put the test tube in a rack where it will remain for 2-3 days and not be disturbed. Soil particles will then settle according to size with the larger particles settling first at the bottom.
6. Any gravel/small stones and sand will settle quickly and their depths can be marked on the test tube after approximately 1 minute.
7. Once sand has settled, clay will then settle on top and then if left long enough (until the water is reasonably clear) silt will eventually settle.
8. The time for this varies between soil samples and can take anything from 1 day to a couple of weeks.
9. The colour of the water will never be completely clear as salts and minerals have dissolved and are therefore always suspended.
10. Humus will float on the top.
11. The air layer at the top will give an indication of the air content in the soil sample.

 

 

Results:

 

           Test Tube :

a)    Sand layer thickness = 1.7 cm

 

b)    Clay layer thickness = 0.3  cm

 

c)     Silt layer thickness = 0.4  cm

CONCLUSION:

 

What does this practical tell you about the composition of your soil sample in terms of soil composition and particle size?

          

Loamy soil is made up of the correct nutrients, water and air. A perfect environment for plants to be sustainable. We will use Loamy soil in our Window Farm.