Agri Quiz: Soil Science: Soil and its Component

Correct Answer: Floor or Ground
The term 'Soil' originates from the Latin word 'Solum'. 'Solum' directly translates to Floor or Ground.

Correct Answer: Relief
Dokuchaiev's early equation for soil formation (S = f(p, cl, o...)) included parent material (p), climate (cl), and organisms (o). Relief (r) was added later by Hans Jenny.

Correct Answer: Relief and Time
Hans Jenny (1941) modified Dokuchaiev's model by incorporating relief (r) and time (t) as crucial soil forming factors. His equation is represented as S = f(cl, r, p, b, t,...).

Correct Answer: Climate and Biosphere
J.S. Joffe (1949) categorized the soil forming factors into active and passive groups. Climate and Biosphere (organisms) were designated as the active factors influencing soil development.

Correct Answer: Ectodynamomorphic soils
When climate is the dominant factor in soil formation, the resulting soils are termed Ectodynamomorphic soils. Examples include Laterite and Podzol soils formed under specific climatic conditions.

Correct Answer: G. Milne
G. Milne (1935) introduced the term 'Catena'. It describes a sequence of soils down a slope, where differences are primarily due to relief or topography, assuming other factors are relatively constant.

Correct Answer: Endodynamomorphic soils
Soils whose characteristics are mainly dictated by the nature of their parent material are known as Endodynamomorphic soils. This contrasts with Ectodynamomorphic soils, which are primarily influenced by climate.

Correct Answer: 200-300 years
Soil formation is a slow process. Under favourable conditions, it is estimated to take about 200-300 years to form one inch of topsoil.

Correct Answer: V. V. Dokuchaiev
V. V. Dokuchaiev is recognized as the 'Father of Soil Science'. He is also considered the founder of modern pedology, establishing soil as a natural body worthy of independent study.

Correct Answer: Joffe and Marbut
Joffe and Marbut provided a definition of soil emphasizing its natural origin. They described it as a natural body developed through the action of natural forces on natural materials.

Correct Answer: 45%
A typical soil composition by volume consists of solids and pore space. Mineral materials (inorganic solids) constitute about 45% of the total soil volume.

Correct Answer: 50%
Pore space, which holds soil air and soil water, accounts for approximately 50% of the total volume in a typical soil. This space is roughly equally divided between air (25%) and water (25%) under ideal conditions.

Correct Answer: Pedology
Pedology is the branch of soil science focused on understanding soil as a natural body. It encompasses the study of soil formation (genesis), classification, mapping (survey), and distribution.

Correct Answer: Edaphology
Edaphology is the branch of soil science that investigates soil from the perspective of plant growth. It focuses on how soil properties affect plants and how soil serves as a habitat for them.

Correct Answer: National Bureau of Soil Survey and Land Use Planning (NBSS&LUP)
The National Bureau of Soil Survey and Land Use Planning (NBSS&LUP) acts as the main repository for soil information in India. It is responsible for soil surveys and delineating agro-ecological regions.