Soil Organic Matter MCQs Quiz 8 Posted on May 3, 2026Author agropublishers 0 1. Breakdown of organic matter into simpler substances is known as ____________ Aggregation Leaching Humification Decomposition 2. Soil organic matter most likely to accumulate due to slow decomposition in ___________ climate Arid dry climate Hot tropical climate Cold climate Equatorial climate 3. Which factor plays the most critical role in maintaining long-term soil fertility? Soil texture Soil moisture Soil organic matter content Soil Structure 4. In soil, humus is __________ part of organicm matter Inorganic Mineral Stable Easily decomposed 5. A major contribution of farmyard manure (FYM) to soil organic matter (SOM) is_____________- Rapid nutrient release only Reduction in microbial biomass Increase in labile and stable carbon pools Decrease in soil porosity 6. The high water-holding capacity of soils rich in SOM is mainly attributed to __________ Hydrophobic nature of silt particles Coarse particle fraction Macropore dominance Hydrophilic nature of organic colloids 7. Carbon fraction of soil organic matter is known as ______________________ Soil organic carbon Inorganic carbon Total organic matter Humus carbon 8. Easily decomposable fraction of Soil Organic Matter is ___________ Stable pool Labile fraction Passive pool Humus 9. Vermicompost improves soil porosity primarily because it ___________________ Promotes stable macroaggregate formation Adds fine sand particles to the soil Creates a hard pan in the subsoil Reduces root penetration 10. How does adequate soil organic matter increase soil resilience to environmental stress? By increasing nutrient sink By improving structural stability and aggregation By compacting soil By increasing erosion risk Loading … Question 1 of 10
