Which of the following characteristics describe bio-drainage systems for waterlogged and canal-seepage affected agricultural lands?
Options:
(A) Bio-drainage utilizes fast-growing, deep-rooted, highly transpiring tree species (such as *Eucalyptus tereticornis* or *Casuarina equisetifolia*) to biologically pump and lower shallow water tables
(B) It operates with zero electrical energy costs and requires no physical drainage disposal channels
(C) It is highly effective as an interceptor bio-shield strip planted parallel to unlined irrigation canals to arrest seepage flows
(D) Long-term bio-drainage in arid zones can cause localized root-zone salt accumulation requiring periodic flushing or integration with tile drains
Answer Key:
A, B, C, D
Step-by-Step Solution & Explanation
All four statements are established characteristics of bio-drainage technology:
- A: High-transpiration phreatophyte tree species transpire $1000 - 2500\text{ mm/year}$ of water directly from shallow groundwater.
- B: Solar energy powers the biological transpiration pump, avoiding effluent disposal issues.
- C: Interceptor tree strips along canal boundaries consume canal seepage before it waterlogs adjacent crop fields.
- D: Transpiration extracts pure water while leaving salts behind in the subsoil, creating a salt accumulation zone over decades that requires management.