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