Question

Appu’s father plans on opening an Anthurium flower farm. He read that Anthurium plants require soils with good water absorption capacity along with good aeration. He has three choices: Clayey soil, Sandy loam soil and coco peat (an artificial soil made from coconut husks). He took 50g of each soil and determined the volume of water it absorbed. He also determined the soil particle size using a microscope and tabulated the results.

$\begin{array}{ccc}\text{Soil Type}& \text{Volume of water absorbed by 50g of soil}& \text{Particle size}\\ \text{Clayey}& \text{35 mL}& \text{0.002 mm}\\ \text{Sandy Loam}& \text{15 mL}& \text{1 mm}\\ \text{Coco Peat}& \text{350 mL}& \text{1 mm}\end{array}$

Which soil should Appu’s father choose?

• A. Clayey
• B. Sandy
• C. Coco Peat
• D. Can’t say with the given information

Answer 1

The correct option is C

Coco Peat

To determine the water absorbing capacity of soil we need to find the percentage of water absorption. This is given by:

Percentage of Water Absorption = $\frac{\text{Weight of water absorbed in grams}}{\text{Weight of soil in grams}}\times 100$

It is given that the weight of soil taken is 50g. We have also been given the volume of water absorbed in each case. But to find the percentage, we need the weight of water.

It is important to know that 1mL of water weighs 1g. So, 35mL of water weighs 35g and so on.

We can then use the formula above to find the percentage of water absorption:

$\begin{array}{ccc}\text{Soil Type}& \text{percentage of water}& \text{Particle size}\\ & \text{absorption}& \\ & & \\ \text{Clayey}& \frac{35g}{50g}\times 100=70\%& 0.002mm\\ \text{Sandy Loam}& \frac{15g}{50g}\times 100=30\%& 1mm\\ \text{Coco Peat}& \frac{350g}{50g}\times 100=700\%& 1mm\end{array}$

Thus, it can be seen that coco peat has the best moisture absorption capacity at 700% while clayey soil also has a good water retention capacity at 70%. Sandy soils absorb water the least.

Also, note from the table the sizes of soil particles. Larger the size of particles, better the aeration. Coco Peat and Sandy loam both have equally good aeration. Thus, the best soil is Coco Peat because the requirement is high water absorption with good aeration.