Agriculture and Environment Soil Science & Land Management 2 — Questions and Answers
Question 1: What is cation exchange capacity (CEC) a measure of in soil science?
- The rate of water infiltration
- The soil's ability to hold and supply nutrients to plants (Correct answer)
- The amount of organic carbon present
- The rate of microbial decomposition
Correct answer: The soil's ability to hold and supply nutrients to plants
CEC measures the soil's capacity to hold positively charged nutrient ions (cations) like calcium, magnesium, and potassium for plant uptake.
Question 2: Which US federal program provides financial incentives to farmers for implementing conservation practices on their land?
- Farm Service Agency Loan Program
- Conservation Reserve Program (CRP) (Correct answer)
- National Organic Program
- Federal Crop Insurance Program
Correct answer: Conservation Reserve Program (CRP)
The Conservation Reserve Program pays farmers to retire highly erodible or environmentally sensitive cropland from production for conservation purposes.
Question 3: What soil property is most directly improved by adding lime to agricultural fields?
- Nitrogen content
- Soil pH (Correct answer)
- Water-holding capacity
- Bulk density
Correct answer: Soil pH
Agricultural lime (calcium carbonate) raises soil pH by neutralizing acidity, making nutrients more available to crops.
Question 4: Which erosion control practice involves planting crops along the natural contour lines of a slope?
- Strip cropping
- Contour farming (Correct answer)
- Terracing
- Windbreaks
Correct answer: Contour farming
Contour farming involves plowing and planting across the slope following contour lines, which slows water runoff and reduces erosion.
Question 5: What is soil compaction and why is it problematic for crops?
- Soil enrichment that boosts root growth
- Increased soil density that restricts root growth and water infiltration (Correct answer)
- Improved soil structure from organic matter
- Enhanced nutrient cycling from microbial activity
Correct answer: Increased soil density that restricts root growth and water infiltration
Soil compaction increases bulk density, restricting root penetration, reducing pore space, and limiting water and air movement through the soil profile.
Question 6: What percentage of US cropland uses some form of conservation tillage practice?
- Less than 10%
- About 25%
- Over 50% (Correct answer)
- Nearly 100%
Correct answer: Over 50%
Over 50% of US cropland uses conservation tillage practices, which have significantly reduced soil erosion compared to conventional tillage.
Agriculture and Environment Soil Science & Land Management 2
What is cation exchange capacity (CEC) a measure of in soil science?