Which one of the following is not a soil forming factor ?

Soil formation, or pedogenesis, is governed by five primary factors: parent material, topography (relief), climate, biological activity (organisms), and time [1]. Parent material provides the initial mineral substance and determines the soil's chemical and physical properties [3]. Topography influences the rate of erosion and water infiltration, while climate (temperature and precipitation) controls the intensity of weathering and organic matter decomposition [2][3]. Biological activity involves the role of vegetation and microorganisms in nutrient cycling [4]. While human activities like agriculture and urbanization can significantly impact existing soil profiles and degradation, 'human habitation' is not classified as one of the five fundamental natural factors of soil formation in classical pedology [1]. Therefore, human habitation is the correct answer as it is not a primary soil-forming factor.

Sources

1. [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 5: Geomorphic Processes > Soil-forming Factors > p. 44
2. [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 25: Agriculture > 25.13. SOIL > p. 366
3. [2] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 6: Soils > INTRODUCTION > p. 1
4. [4] NCERT. (2022). Contemporary India II: Textbook in Geography for Class X (Revised ed.). NCERT. > Chapter 1: The Rise of Nationalism in Europe > SOIL AS A RESOURCE > p. 8