GATE Irrigation and Drainage Engineering: Soil-Water-Plant Relationship – Previous Year Questions

8 GATE previous year questions on Soil-Water-Plant Relationship (Irrigation and Drainage Engineering, Agricultural Engineering) with answers and explanations, from every paper.

GATE 2021 AG Q31 (1 mark, Numerical answer) – Saturated soil extract contains Mg²⁺5.68,Na⁺9.90,HCO₃⁻11.20 meq/L. HCO₃⁻/Ca²⁺=2.8. Find sodium adsorption ratio, to two decimals.
GATE 2023 AG Q42 (2 marks, Multiple choice) – Soil field capacity/wilting moisture are.21/.09 cm³/cm³,root depth .90 m and MAD50%. January/February/March reference ET is 11/12/14 mm/day, effective…
GATE 2023 AG Q59 (2 marks, Numerical answer) – Irrigation water salt concentration is 3.5 meq/L and soil saturation-extract concentration15.2 meq/L. Leaching efficiency55%. March reference ET150…
GATE 2024 AG Q22 (1 mark, Multiple select) – Which measure in-situ volumetric soil moisture? Select all that apply.
GATE 2025 AG Q25 (1 mark, Multiple select) – Which are adverse effects of soil salinity or alkalinity or both? Select all that apply.
GATE 2025 AG Q40 (2 marks, Multiple select) – A lysimeter is used to measure which processes? Select all that apply.
GATE 2026 AG Q63 (2 marks, Numerical answer) – A soil core cylinder has internal diameter 60 mm and length 100 mm. Moist soil mass is .48 kg and oven-dry soil mass .44 kg. Water density is…
GATE 2026 AG Q64 (2 marks, Numerical answer) – A crop has four 25-day stages:initial, grand growth, mid-season and late-season. Its crop coefficient rises linearly from .4 in the initial stage to…