MCQs Soil Science-58 Posted on November 30, 2025November 30, 2025Author agropublishers 0 MCQs Soil Science-58 1. Which fraction of soil organic matter decomposes fastest? Fresh residues Humin Humic acid Humus 2. Rhizobia, bacteria live in the roots of leguminous plants, play a crucial role in _________ Pathogen defense Nitrogen fixation Nutrient uptake Water absorption 3. Humus increases soil fertility by improving ————- Drainage Cation Exchange Capacity All of these Soil aeration 4. ————– are the most efficient and dominant organisms in decomposing lignin-rich materials like wood Algae Fungi Bacteria Actinomycetes 5. Clay soils generally have higher fertility than sandy soils True False 6. Root exudates promote microbial growth in the rhizosphere True False 7. Soil enzyme activity decreases with heavy metal pollution True False 8. A higher C:N ratio in residues leads to ———- Nitrogen immobilization Increased humus decay Nitrogen mineralization Faster decomposition 9. Nitrogen is usually the most limiting nutrient in crop production True False 10. A productive soil under one crop may ———- Be always equally productive for all crops Never change in productivity Lose fertility instantly Be unproductive for another Loading … Question 1 of 10
