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? Humus Humin Fresh residues Humic acid 2. Nitrogen is usually the most limiting nutrient in crop production True False 3. A higher C:N ratio in residues leads to ———- Faster decomposition Increased humus decay Nitrogen mineralization Nitrogen immobilization 4. ————– are the most efficient and dominant organisms in decomposing lignin-rich materials like wood Fungi Actinomycetes Algae Bacteria 5. Humus increases soil fertility by improving ————- Soil aeration All of these Cation Exchange Capacity Drainage 6. 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 7. Soil enzyme activity decreases with heavy metal pollution False True 8. Rhizobia, bacteria live in the roots of leguminous plants, play a crucial role in _________ Water absorption Nutrient uptake Pathogen defense Nitrogen fixation 9. Clay soils generally have higher fertility than sandy soils False True 10. Root exudates promote microbial growth in the rhizosphere True False Loading … Question 1 of 10
