OBJECTIVE FORESTRY

Detailed explanation-1: -It is pillar like ped, which is rounded at the top structure, is known as columnar.

Detailed explanation-2: -Peds are described by their shape-for example: blocky, columnar, massive, single grain or platy.

Detailed explanation-3: -Blocky. In blocky structure, the structural units are blocklike or polyhedral. They are bounded by flat or slightly rounded surfaces that are casts of the faces of surrounding peds. Typically, blocky structural units are nearly equidimensional but grade to prisms and to plates.

Detailed explanation-4: -There are five major classes of structure seen in soils: platy, prismatic, columnar, granular, and blocky. There are also structureless conditions.

Detailed explanation-5: -Prism-like: In prism like structure, the vertical axis is more developed than horizontal, giving a pillar like shape. They are commonly found in the subsurface horizons of semiarid and arid regions. The prisms having rounded tops are called columnar and mostly occur in subsoils of salt-affected soils.