Soil Organic Matter MCQs Quiz 6 Posted on May 3, 2026Author agropublishers 0 1. Which process transforms unstable organic matter into stable, resistant compounds? Immobilization Humification Mineralization Leaching 2. Soil fertility depends most strongly on ___________ Soil organic matter content Water availability Silt content Sand content 3. Soil organic matter increases water holding capacity primarily due to the presence of ___________ Gravels Organic colloids Large silt particles Sand particles 4. Immobilization is the process by which nutrients are converted from _____________ to ___________ Liquid → gas Solid → gas Organic → inorganic Inorganic → organic 5. Which component most strongly contributes to the formation of stable soil organic matter (humus)? Proteins Lignin and its derivatives Sugars Nucleic Acid 6. Soil organic matter accumulation is highest in__________ Cold soils Sandy soils Dry soils Hot soils 7. Which factor primarily controls the rate of humification? Water content Soil depth Rock type Quality and composition of organic inputs 8. Which condition shifts the balance toward carbon loss from soil? Low temperature Clay content Organic additions Frequent aeration and disturbance 9. Nitrogen mineralization results in the release of _________ nitrogen Ammonium form only Gaseous form only Organic nitrogen Inorganic nitrogen 10. Soil organic matter improves soil resilience primarily by _________ Facilitating vertical nutrient movement Hardening the soil Enhancing structural stability Increasing erosion Loading … Question 1 of 10
