Amelioration

The action of ameliorating one material with another. This is achieved by adding and uniformly mixing one material, such as sand, to another, such as a loam. The aim is to alter the relative proportions of the different soil particles; essentially one material is diluted by the addition of another.

A formula can be used to help determine how much sand (in kg) is needed to be mixed with one unit (kg) of an existing soil to end up with a desired sand content in a final mix:

M = (D-E)/(I-D)

Mass (in kg) of the desirable sand which is being used for amelioration;

D = The Desirable sand content (within a required particle size range, e.g. 0.125-0.500mm) in the final mix;

E = The percentage of sand, within the required particle size range, that is currently present in the Existing soil which is to be ameliorated;

I = The percentage of sand, within the required particle size range, that is present within the sand which is to be Imported and used for the amelioration.

For example, if D = 85%; E= 40%, and I = 95%, the formula calculates as:

M= (85-40)/(95-85)= 45/10=4.5

This means that an estimated 4.5kg of the Imported sand needs to be mixed with 1kg of the Existing soil to result in a Desirable overall ameliorated mixture of soil that contains 85% sand within the required particle size range of 0.125-0.500mm.