Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

Which of the following best describes clay soils?

1. Poorly draining and gritty

2. Firmly binding with little drainage

3. Dry and crumbly

4. Heavy and loose

The correct answer is: Firmly binding with little drainage

Clay soils are characterized by small particle size and a high degree of cohesion, which leads to a firmly binding texture. This results in very little drainage capability because the tight packing of particles impedes the movement of water through the soil. Such soils tend to retain moisture, which can make them feel sticky when wet and hard when dry. This property of clay soils can lead to challenges in building structures, gardening, and agriculture, as waterlogging can occur if drainage solutions are not implemented. The other options do not accurately capture the essential nature of clay soils. While clay may feel heavy due to its density, it is not typically loose; it lacks the airy structure associated with loamy or sandy soils. Clay soils are also not described as dry and crumbly, as they retain a considerable amount of moisture, nor are they gritty, which is a trait more associated with sandy soils.