Question

Match List-I with List-II

List-I (Soil parameters) & List-II (Measurement)
(A) Bulk Density & (I) $Cl^{36}$
(B) Soil water content & (II) $C^{13}$
(C) Seepage & (III) $H^2$
(D) Soil salinity & (IV) Am$-$Be
(E) Soil aggregation & (v) $Cs^{137}$

• (A) - (V), (B) - (IV), (C) - (III), (D) - (I), (E)-(II)
• (A) - (IV), (B) - (V), (C) - (III), (D) - (I), (E) - (II)
• (A) - (III), (B) - (IV), (C) - (V), (D) - (II), E - (I)
• (A) - (IV), (B) - (III), (C) - (V), (D) - (II), (E) - (I)

Hint:

To remember this:
- Neutron moisture probe: Uses the Am-Be source to measure soil water.
- Gamma probe: Uses Cs-137 to measure bulk density.
- Water tracer: Uses deuterium (H-2) to trace seepage.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Nuclear techniques and isotopic tracers are highly precise tools used in soil science and hydrology to measure soil physical properties, water movement, and nutrient cycles.

Step 3: Detailed Explanation:
Let us match each soil parameter in List-I with its corresponding nuclear measurement method/isotope in List-II:
- (A) Bulk Density $\rightarrow$ $Cs^{137$ (V):} Cesium-137 ($Cs^{137}$) is a radioactive isotope used widely in gamma-ray attenuation probes to measure soil bulk density and trace soil erosion/movement.
- (B) Soil water content $\rightarrow$ Am$-$Be (IV): The Americium-Beryllium ($\text{Am}-\text{Be}$) radioactive source emits fast neutrons.
In neutron moisture probes, these fast neutrons are thermalized (slowed down) primarily by hydrogen atoms in soil water, allowing accurate measurement of Soil water content.
- (C) Seepage $\rightarrow$ $H^2$ (III): Deuterium ($H^2$), a stable isotope of hydrogen, is used as an ideal, non-reactive environmental tracer to monitor water flow, infiltration, and groundwater seepage.
- (D) Soil salinity $\rightarrow$ $Cl^{36$ (I):} Chlorine-36 ($Cl^{36}$), a radioactive isotope of chlorine, is used as a highly sensitive tracer to study chloride movement, salt accumulation, and Soil salinity dynamics.
- (E) Soil aggregation $\rightarrow$ $C^{13$ (II):} Carbon-13 ($C^{13}$) is a stable isotope of carbon used to study the turnover of organic carbon fractions that bind soil particles into stable aggregates.
This matching sequence gives: (A) - (V), (B) - (IV), (C) - (III), (D) - (I), (E) - (II).
This matches Option (A).

Step 4: Final Answer:
The correct matching sequence is (A) - (V), (B) - (IV), (C) - (III), (D) - (I), (E) - (II).