Exam 4: Soil Architecture and Physical Properties

Which type of soil structure is typically found in surface soil (A horizons)?

Soil tilth refers to _____.

Flocculation is the process by which certain chemicals in the soil stabilize large soil aggregates.

Subsoiling is a primitive deep tillage technique that results in extremely high subsoil bulk density.

For most soils, plowing and harrowing every year improves soil tilth in the long run.

Using a textural triangle chart, it can be determined that a soil with 45% sand and 20% clay belongs to the ___textural class.

The plasticity index is used to determine soil texture.

Brown and red colors in subsurface horizons are caused by __ in the soil.

A soil with a bulk density equal to 0.35 Mg/m³ is most likely what type of soil?

Fungal hyphae have an important influence on soil structure because they ______.

If a dry soil high in certain types of ____ is moistened, it is likely to swell up with enough force to crack pavements and building foundations.

Compared to a similar soil under native vegetation, a soil with a long history of conventionally tilled cropping would have less micropore space.

Colloidal properties are exhibited by the ___ fraction of soils.

A friable soil is usually more likely to be indurated.

The percent of total pore space in a soil can be calculated if only the particle density and the organic matter content are known.

Which of the following is not a textural class name?

Soil colors are scientifically described by ____ color designations such as 10YR3/4.

The drainage class of a soil (the degree to which the soil becomes water-saturated during the year) can be judged by the presence and location of gley in the soil profile.

Fungal hyphae play an important role in stabilizing surface soil aggregates.

Light colored surface soils are likely to be warmer than dark-colored surface soils if soil moisture and other conditions are the same.