Which of the following option determines percolation and water holding capacity of soils?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Grain size, soil composition and aggregation
Option (1) Climate — Incorrect. Climate affects how soil forms, not directly how water passes through it.
Option (2) Grain size, soil composition and aggregation — Correct. These properties decide how easily water passes through the soil (percolation) and how much it holds. Sandy soil with large grains drains fast; clay holds water.
Option (3) Weathering process — Incorrect. Weathering is part of how soil is made from rock.
Option (4) Soil development — Incorrect. Soil development also explains why soils differ, not their water-holding capacity itself.
Note: This question is from the topic “Major Abiotic Factors” in Chapter 13, Organisms and Populations, of the pre-rationalised NCERT book. This portion is not in the present NCERT book, where the chapter is now Chapter 11, Organisms and Populations. The extract below is from the pre-rationalised edition.
NCERT Extract (Pre-rationalised edition, Chapter 13, Organisms and Populations):
Major Abiotic Factors – “… Soil: The nature and properties of soil in different places vary; it is dependent on the climate, the weathering process, whether soil is transported or sedimentary and how soil development occurred. Various characteristics of the soil such as soil composition, grain size and aggregation determine the percolation and water holding capacity of the soils.”