The Soil: Quiz

Read the following statement and question then, based on what you have learnt from the previous screens, select the correct answer...

Drainage and aeration of heavy clay soils can be immediately improved by the incorporation of gypsum (a hydrated form of calcium sulphate).

Without having to understand the chemistry involved, what physical changes to the soil due to the addition of gypsum might produce this improvement?

the gypsum improves the soil texture by increasing the size of the soil particles

the gypsum improves the soil structure by increasing the size of the soil particles

the gypsum improves the soil structure by increasing the degree of aggregation of soil particles

try again

No, the size of the soil particles and therefore the soil texture remains the same. The gypsum causes the soil to aggregate, introducing larger pore spaces which improve aeration and speeds water movement (i.e. drainage).
No, the gypsum does improve the soil structure but it does this by causing the soil to aggregate, thereby introducing larger pore spaces which improves aeration and drainage. The size of soil particles remains unchanged.

Yes, the gypsum causes the soil to aggregate, introducing larger pore spaces which improve aeration and speeds water movement (i.e. drainage).

Well done, you answered correctly. Use the 'next' button to proceed.