Soil Science Agricultural Chemistry

Step 1: Understanding the Concept:
The question asks to match the primary elemental components of humus (stable organic matter in soil) with their approximate percentage content.

Step 3: Detailed Explanation:
The elemental composition of humus can vary, but a typical approximation is as follows:
$%5Cbegin%7Barray%7D%7Brl%7D%20%5Cbullet%20%26%20%5Ctext%7B(A)%20Carbon%20(C)%3A%20This%20is%20the%20main%20component%20of%20all%20organic%20matter.%20In%20humus%2C%20it%20typically%20ranges%20from%2055-60%25.%20So%2C%20(A)%20matches%20(III).%7D%20%5C%5C%20%5Cbullet%20%26%20%5Ctext%7B(B)%20Oxygen%20(O)%3A%20Oxygen%20is%20another%20major%20component%2C%20typically%20making%20up%20around%2035-40%25.%20So%2C%20(B)%20matches%20(I).%7D%20%5C%5C%20%5Cbullet%20%26%20%5Ctext%7B(C)%20Hydrogen%20(H)%3A%20Hydrogen%20is%20present%20in%20smaller%20amounts%2C%20usually%20around%20~5%25.%20So%2C%20(C)%20matches%20(II).%7D%20%5C%5C%20%5Cbullet%20%26%20%5Ctext%7B(D)%20Nitrogen%20(N)%3A%20Nitrogen%20content%20is%20also%20relatively%20small%2C%20but%20crucial%20for%20soil%20fertility.%20There%20seems%20to%20be%20a%20mismatch%20in%20the%20provided%20options%20as%20nitrogen%20is%20typically%20around%203-6%25%2C%20similar%20to%20hydrogen.%20Given%20the%20choices%2C%2015%25%20(IV)%20is%20a%20possible%2C%20though%20high%2C%20value%20provided%20in%20some%20contexts%2C%20making%20it%20the%20only%20remaining%20match%20for%20Nitrogen.%20So%2C%20(D)%20matches%20(IV).%7D%20%5C%5C%20%5Cend%7Barray%7D$ The most consistent matching based on the dominant elements is A-III, B-I, C-II, D-IV.

Step 4: Final Answer:
The correct matching option is (A) - (III), (B) - (I), (C) - (II), (D) - (IV).

Step 1: Understanding the Concept:
This question requires matching specific terms from soil science (pedology) with their correct definitions.

Step 3: Detailed Explanation:
$%5Cbegin%7Barray%7D%7Brl%7D%20%5Cbullet%20%26%20%5Ctext%7B(A)%20Azonal%20soils%3A%20These%20are%20immature%20soils%20that%20lack%20well-developed%20horizons.%20They%20are%20often%20found%20on%20steep%20slopes%20or%20in%20recent%20alluvial%20deposits.%20This%20matches%20the%20definition%3A%20%22Soils%20have%20uniformity%20from%20the%20top-surface%20to%20the%20base%2C%20and%20do%20not%20have%20well-developed%20soil%20horizons.%22%20So%2C%20(A)%20matches%20(III).%7D%20%5C%5C%20%5Cbullet%20%26%20%5Ctext%7B(B)%20Regoliths%3A%20This%20is%20the%20layer%20of%20loose%2C%20heterogeneous%20superficial%20material%20covering%20solid%20rock.%20It%20includes%20dust%2C%20soil%2C%20broken%20rock%2C%20and%20other%20related%20materials.%20This%20matches%20the%20definition%3A%20%22Zone%20of%20loose%20and%20unconsolidated%20weathered%20rock%20materials.%22%20So%2C%20(B)%20matches%20(IV).%7D%20%5C%5C%20%5Cbullet%20%26%20%5Ctext%7B(C)%20Ped%3A%20This%20is%20a%20unit%20of%20soil%20structure%2C%20which%20is%20a%20natural%20aggregate%20of%20soil%20particles%20(sand%2C%20silt%2C%20and%20clay)%20held%20together.%20This%20matches%20the%20definition%3A%20%22An%20individual%20natural%20aggregate%20of%20soil%20particles.%22%20So%2C%20(C)%20matches%20(I).%7D%20%5C%5C%20%5Cbullet%20%26%20%5Ctext%7B(D)%20Edaphons%3A%20This%20is%20a%20collective%20term%20for%20all%20the%20organisms%20that%20live%20in%20the%20soil%2C%20including%20bacteria%2C%20fungi%2C%20protozoa%2C%20and%20larger%20animals.%20This%20matches%20the%20definition%3A%20%22Organisms%20living%20in%20the%20soil%20or%20ground%22.%20So%2C%20(D)%20matches%20(II).%7D%20%5C%5C%20%5Cend%7Barray%7D$ The correct set of matches is A-III, B-IV, C-I, D-II.

Step 4: Final Answer:
The correct matching option is (A) - (III), (B) - (IV), (C) - (I), (D) - (II).

High-Yield Trend

Chapter Questions
3 MCQs

Official Solution

Official Solution

Official Solution

Soil Science Agricultural Chemistry

High-Yield Trend

Chapter Questions 3 MCQs

Official Solution

Official Solution

Official Solution

Chapter Questions
3 MCQs