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