A soil has no visible aggregates, very low porosity, and poor root penetration. What soil structure is described?

• A. Massive structure
• B. Plate-like structure
• C. Granular structure
• D. Blocky structure

Answer: (A)

When a soil appears as a dense, cohesive mass with no visible aggregates and very little pore space, the structure described is massive. This means the particles are tightly bound together with almost no peds or clumps, so internal porosity is extremely low and movement of air and water is limited. Such compactness also explains the poor root penetration, since roots struggle to push through a solid, uncrumbled horizon.

Plate-like structures would show thin, flat plates with some separation between them and a bit more movement around them, even if porosity is reduced. Granular structures are crumb-like and friable, giving high porosity and easy rooting. Blocky structures form visible blocks or cubes with clearer boundaries and more internal pore networks than a massive horizon. The absence of any observable aggregates and the extremely low porosity point most directly to a massive soil structure.