Exam 4: Soil Architecture and Physical Properties

Soils of good tilth and high productivity are usually characterized by stable aggregation and a high percentage of macropores.

Dull gray colors are characterized by _____.

The plasticity index is the difference between the plastic limit and the liquid limit.

A sticky, putty-like feel indicates a high percentage of which soil separate?

Tillage when the soil is too wet is likely to increase the soil bulk density.

In many soil profiles, the subsoil is high in clay, but is also quite permeable to percolating water.Why?

The difference between the liquid and plastic limits of a soil is _______.

Which color would be typical of a well drained, low-organic matter sandy surface soil?

For which substance would the particle density equal the bulk density?

Practices that add organic matter and reduce tillage can be expected to most significantly increase the _____ in a soil.

Which of the following practices is(are) useful in stabilizing surface soil structure?

When preparing a surface soil seedbed, the soil should generally be in the loosest, least dense soil condition in the row where the seed is placed.

The percentages of which soil components represent the minimum information necessary in order to determine the textural class of a soil?

Proper timing of tillage is generally more difficult for a clayey than for a sandy soil.

For any soil, the bulk density is always lower than the particle density.

A landscaping contractor wants to change the texture of a silt loam soil to meet the specifications for a loam.S/he would most likely do so by adding ______ to the soil and mixing it well.

Because of their greater surface area per unit of soil mass, silt loams soils generally have a greater capacity than loamy sand soils to ___.

A chroma greater than 4 generally indicates a soil in good tilth.

Soil consistence changes with changes in soil water content.

Texture describes the ____ of particles in a soil.