MCQs Soil Science-52 Posted on May 10, 2025August 30, 2025Author agropublishers 0 1. What is the primary mechanism by which soil organic matter enhances soil nutrient retention? Regulating Cation exchange capacity (CEC) Soil pH buffering Improving water-holding capacity Improving soil structure Reducing soil porosity through compaction 2. Phosphorus (P) precipitation, along with limited plant availability in soil with high pH, is mainly attributed to ___________? High iron (Fe) and aluminum (Al) content Low microbial activity High level of organic matter High calcium content 3. _________ rocks are formed from the cooling and crystallization of magma deep within the Earth’s crust Igneous None of these Metamorphic Sedimentary 4. Which of the following practices can reduce evaporation and increase infiltration? Mulching Siltation Overgrazing Crop Rotation 5. ________________ does NOT significantly affect the bioavailability of toxic chemicals Chemical solubility Organic matter content All of these Soil pH Atmospheric pressure 6. How can heavy metal-contaminated soil be improved? Phyto-stabilization All of these Phytoremediation Amendments 7. __________ is a soil particle that feels powdery to the touch when dry Silt Clay Sand Loam 8. Exchangeable and soluble metal ions in soils are termed as _________ Fixed Ions Adsorbed Ions Residual Ions Available Ions 9. During which geologic time did Earth form and undergo its early development? Paleozoic Precambrian Cenozoic Mesozoic 10. Macronutrients are required in large amounts and normally constitute __________ of a plant’s dry weight Less than 400 mg kg –1 (0.04%) approximately 500 mg kg –1 (0.05%) 10,000 mg kg –1 (1.0%) or more 1000 mg kg –1 (0.1%) or more Loading … Question 1 of 10
