Subtopic: Planning, design and layout of surface and sub-surface drainage systems
Question Statement:
Which of the following field conditions justify the installation of a subsurface relief drainage system?
Options:
(A) High water table persisting in the crop root zone causing aeration stress
(B) Soil salinization caused by upward capillary movement of saline groundwater
(C) Impervious surface crusting caused by raindrop impact
(D) Waterlogging in irrigated agricultural lowlands lacking natural outlet
Answer Key:
A, B, D
Step-by-Step Solution & Explanation
Subsurface drainage lowers water tables to eliminate root zone saturation (A), facilitates leaching of excess salts to control soil salinity (B), and provides relief from groundwater waterlogging (D). Surface crusting is an infiltration/soil management issue addressed by tillage or amendments, not subsurface tile drains.