Soil-Water-Plant Relationships

• Classification of Irrigation Efficiencies:
• Water Conveyance Efficiency ($\eta_c$): Ratio of water delivered to the farm fields to water diverted from the source canal network: $\eta_c = (W_f / W_d) \times 100$. (True)
• Water Application Efficiency ($\eta_a$): Ratio of water stored in the crop root zone during irrigation to water delivered to the field, directly governed by the irrigation method (surface, sprinkler, drip). (True)
• Economic Efficiency: Evaluates overall economic returns generated per unit cost/volume of irrigation water across the system. (True)
• Conclusion: (A), (B) and (C) are all correct (Option 4).

Correct option: (4) (A), (B) and (C).

• Grain Storage Silo Classifications (Deep vs. Shallow Bins):
• Statement (I): In a deep bin, plane of rupture strikes the opposite side of structure before it meets the grain surface. $\implies$ True.
• In deep grain bins, the internal plane of rupture of the granular mass intersects the opposite vertical wall before reaching the top free surface of the grain.
• Statement (II): A grain bin can be classified as deep bin when the depth of grain is greater than the equivalent diameter. $\implies$ True.
• By Janssen and Airy criteria, a bin is classified as a deep bin when grain depth $H \gt D \tan(45^\circ + \phi/2) \approx D$.
• Conclusion: Both Statement (I) and Statement (II) are true (Option 1).

Correct option: (1) Both Statement (I) and Statement (II) are true.

• Confined (Artesian) Aquifers Hydrogeology:
• Artesian designation: An aquifer bounded above and below by impermeable confining strata (aquicludes), maintaining pore water under hydrostatic pressure. (Correct)
• Recharge localization: Recharge occurs exclusively in exposed outcrop recharge areas where permeable strata contact ground surface. (Correct)
• Piezometric surface: The imaginary hydrostatic head surface (piezometric level) can coincide with or rise substantially above the upper confining layer. (Correct)
• Semi-confined / Leaky aquifer: A confined aquifer bounded by semi-pervious strata (aquitards) through which vertical cross-leakage occurs is classified as a leaky aquifer. (Correct)
• Conclusion: (A), (B), (C) and (D) (Option 3).

Correct option: (3) (A), (B), (C) and (D).