Question

a) What do you mean by the water absorption capacity of soil? [1 mark]
(b) A dry soil sample weighing 100 g is taken. A small quantity of water is added to this soil sample. The water got completely absorbed by the soil sample. After adding water, the soil sample weighs 125 g. Calculate the percentage of water absorbed by the soil sample. [2 marks]

Answer 1

Water absorption capacity of soil can be defined as the ability of the soil to retain the water that passes through it. [1 mark]

Water absorbtion (%) = $\frac{\text{Weight of water absorbed by soil sample (g)}}{\text{Weight of dry soil sample}}\times 100$ [0.5 marks]

Weight of water absorbed by the soil = Final weight of the soil - Initial weight of the soil [0.5 marks]

Weight of water absorbed by the soil = 125 g - 100 g = 25 g [0.5 marks]

Water absorbtion (%) = $\frac{25}{100}\times 100$ = 25% [0.5 marks]