Soil Organic Matter MCQs Quiz 9 Posted on May 3, 2026Author agropublishers 0 1. Which process leads to the formation of chemically complex, recalcitrant organic compounds that resist microbial breakdown? Leaching Mineralization Immobilization Humification 2. Conversion of inorganic nutrients into microbial biomass is called ______________ Nitrification Mineralization Denitrification Immobilization 3. Which composting method involves turning the pile regularly to maintain aerobic conditions and achieve rapid decomposition? Aerobic windrow composting Pit composting Anaerobic digestion Vermicomposting 4. Which organic amendment is most effective in long-term improvement of cation exchange capacity of a sandy soil? Well-decomposed vermicompost Raw poultry manure Fresh green biomass Fresh FYM 5. Under aerobic conditions, main gas released during decomposition is _________ Hydrogen Carbon dioxide Oxygen Nitrogen 6. Which soil component most significantly influences nutrient availability, structure, and biological activity? Soil water Silt fraction Soil organic matter Sand fraction 7. Vermicompost enhances soil aggregation primarily through ______________ Increasing soil acidity to bind particles chemically Reducing overall soil microbial activity Increasing the sand fraction in soil Production of polysaccharides and other microbial binding agents 8. In soil, ___________________ regulates decomposition rate C:N ratio Soil moisture ratio pH ratio CEC ratio 9. Soil carbon loss is most accelerated under ________________ High clay content Addition of organic matter Increased soil disturbance and oxygen exposure Cool climate 10. Nitrogen mineralization is best defined as the microbial conversion of organic nitrogen into _______ Gaseous nitrogen exclusively Ammonia NH₄⁺, NO₃⁻ Stable organic forms Loading … Question 1 of 10
