ICAR AIEEA PG 2024 - Agricultural Engineering and Technology

In soil science and engineering:
Statement (I) is correct: A soil profile is defined as the vertical section of the soil exposed from the ground surface down through all its master horizons (O, A, E, B, C) to the underlying parent bedrock.
Statement (II) is incorrect: The arrangement or grouping of individual soil particles into definite aggregates, clusters, or structural patterns is defined as Soil Structure, NOT soil texture. Soil Texture refers strictly to the relative proportions of different soil separates (sand, silt, and clay).

Calculation of rainfall volume:
Rainfall depth \(d = 1\text{ cm} = 0.01\text{ m} = 10^{-2}\text{ m}\). Catchment area \(A = 1\text{ km}^2 = (1000\text{ m})^2 = 10^6\text{ m}^2\).
Volume of water \(V = A \times d = 10^6\text{ m}^2 \times 10^{-2}\text{ m} = 10^4\text{ m}^3\) (or 1 hectare-meter = 10,000 \(\text{m}^3\)).

Matching of hydrological processes and principles:
(A) Evaporation matches with (IV) Dalton's law: Evaporation rate from open water is governed by Dalton's law, \(E = C(e_s - e_a)\).
(B) Infiltration matches with (III) Rate of entry of rain water in to soil: Infiltration is the physical process of water penetrating into the soil surface from precipitation.
(C) Low evaporation matches with (II) Humid day: High atmospheric relative humidity (vapor pressure \(e_a\) close to saturation \(e_s\)) substantially reduces the vapor pressure gradient, resulting in low evaporation.
(D) Evapotranspiration matches with (V) Blaney-Criddle: The Blaney-Criddle method is a classic temperature-based empirical formula used to estimate consumptive use (evapotranspiration).
(E) Transpiration matches with (I) Plant leaves: Transpiration is the biological vaporization of water from plant leaves through stomata.