Which of the following is concerned with soil?

The correct answer is A) Edaphic. The word comes from the Greek edaphos, meaning ground or soil, and in ecology edaphic factors cover the physical, chemical and biological properties of soil: texture, structure, pH, organic matter, nutrient status and moisture-holding capacity.

• Climatic (B) refers to atmospheric conditions such as temperature, rainfall, humidity and wind. It is a separate factor group, not a soil factor.
• Biotic (C) refers to living organisms and their interactions, such as plants, animals, microbes and humans. Soil organisms are biotic, but the term as a category is not about soil.
• Topography (D) refers to relief, slope, aspect and elevation. It influences soil formation and erosion, but it describes the land surface, not soil itself.

This is a basic ecology concept that links to Mains questions on soil degradation, agro-climatic zoning and the Soil Health Card scheme launched in 2015, where edaphic parameters are tested to guide fertiliser use.

Trap: Candidates pick Topography because soil formation depends on land relief. The question asks which term is concerned with soil, and that term is Edaphic.