The concrete itself was tinted very slightly to give the impression of poor, starved, natural soil.

The cut describes the edge of the feature, where the feature meets the natural soil.

The fill is what the feature is filled with, and will often appear quite distinct from the natural soil.

They were first reported in natural soils by Newman and Tate (1980).

The river's best protection against runoff is natural soil and vegetation, which absorb pollutants before they can flow into the water.

In natural soils many different cohorts, or groups of microorganisms exist.

They got down and sought the filtration of the natural soil, while the foul cloud washed over them.

The earliest phase remains uncertain, as the excavations could not reach the natural soil.

Its first river model was dug in natural soil with a grapefruit knife.

In order to determine if the natural soil will support the first fill layers, an area can be proofrolled.