Which of the following soil types generally has an electrical conductivity of greater than 4 dS/m and an exchangeable sodium percentage of less than 15%?

Correct option is B

1. Saline Soils:
· These soils have high levels of soluble salts, which lead to an electrical conductivity (EC) greater than 4 dS/m.
· However, the exchangeable sodium percentage (ESP) in saline soils is typically less than 15%, meaning that sodium is not the dominant cation affecting soil properties.
· Saline soils do not exhibit the dispersion issues associated with sodic soils and maintain good soil structure.
2. Why Not the Other Options?
· Normal Soils (a):
· Normal soils have an EC less than 4 dS/m and no salinity or sodicity problems.
· Sodic Soils (c):
· Sodic soils have an ESP greater than 15%, indicating high sodium levels that can cause soil dispersion and poor structure, but their EC is typically low (less than 4 dS/m).
· Saline-Sodic Soils (d):
· These soils have an EC greater than 4 dS/m (like saline soils) and an ESP greater than 15% (like sodic soils), which combines the issues of salinity and sodicity.
Thus, the correct answer is (b) Saline soils.
Information Booster: 1. Key Properties of Soil Types:
· Saline Soils: High salinity (EC > 4 dS/m), low sodium (ESP < 15%).
· Sodic Soils: Low salinity (EC < 4 dS/m), high sodium (ESP > 15%).
· Saline-Sodic Soils: High salinity (EC > 4 dS/m) and high sodium (ESP > 15%).
2. Impacts of Soil Properties:
· High salinity affects water uptake by plants due to osmotic stress.
· High sodium affects soil structure, leading to reduced infiltration and permeability.
3. Management of Saline Soils:
· Leaching soluble salts with good-quality water.
· Improving drainage to prevent waterlogging and salt accumulation.
Additional Knowledge: Saline Soils (b):
· Electrical conductivity is high (> 4 dS/m).
· Exchangeable sodium is low (< 15%).
Normal Soils (a):
· No salinity or sodicity issues.
Sodic Soils (c):
· Sodium percentage is high (> 15%), leading to poor soil structure and dispersion.
Saline-Sodic Soils (d):
· Combines the negative effects of both salinity and sodicity, requiring careful management.