EHST 3350 Exam 2 Review

List two factors that have resulted in the increased demand for food production.

Population growth (largest factor) and increased wealth/incomes.

On a global scale, how many people are undernourished?

About 840 million worldwide.

Since the mid-1960s, total global acreage devoted to agriculture increased by only 8%, but population increased by ____ %.

About 100 % increase.

List four causes/reasons for good farmland loss.

Urban development, erosion, desertification, salinization.

List three primary macronutrients.

Nitrogen (N), Phosphorus (P), and Potassium (K).

What is cation exchange capacity and how can it influence groundwater quality?

Sum of exchangeable cations a soil can adsorb (cmol/kg); affects nutrient retention and mobility.

List three common water pollutants associated with agriculture.

Nutrients (P & N), pesticides, bacteria.

Why do well-drained soils lose more nitrate than poorly drained soils?

Water flows more easily through them, allowing greater leaching.

How is phosphorus typically transported to surface waters?

Attached to eroded soil particles (sediment transport).

List the three processes required for water erosion.

Detachment, transport, and deposition of soil particles.

Why is sediment in surface waters a problem?

Reduces water clarity, blocks sunlight, smothers aquatic habitats.

What are three common agriculture BMPs?

Cover crops, grassed waterways, riparian buffers.

Name three mechanisms for nitrogen reduction by controlled drainage.

Reduced nitrate leaching, denitrification in saturated zones, timed water management.

Under what conditions will riparian buffers be effective at reducing nitrate loadings to surface waters via denitrification; under which conditions will they be ineffective?

Effective in warm, moist, anaerobic conditions; ineffective in sandy, dry, well-drained soils.

How do buffers remove phosphorus?

By trapping sediment and adsorbing P onto organic matter and soil particles.

Name and describe three goals related to stream restoration.

Improve habitat quality, stabilize banks, restore natural hydrology.

To be considered a wetland, what three things must be present?

Hydrology, hydric soils, hydrophytic vegetation.

Why isn't controlled drainage used more in the Piedmont?

Topography and soil types make it inefficient and costly.

What are CAFOs?

Concentrated Animal Feeding Operations.

Which region are most hog CAFOs located in North Carolina?

Coastal Plain region.

What are the components of a typical hog waste system?

Housing, collection pit, lagoon storage, irrigation fields.

Typical hog lagoon wastewater concentrations of TKN, TP, and E. coli?

TKN ~ 500-1000 mg/L; TP ~ 100-200 mg/L; E. coli up to 10⁶ CFU/100 mL (approx.).

What are the storage requirements for a hog waste lagoon?

Levels include sludge storage, treatment volume, temporary storage, and freeboard to berm top.

List five things a CAFO operator must record.

Waste application dates, amounts, field locations, weather conditions, lagoon levels.

Wastewater should be irrigated to maintain soil moisture between ____ and ____.

Field capacity and wilting point.

List some potential environmental threats related to CAFOs using anaerobic lagoons.

Odors, pathogen leaching, nutrient runoff, gas emissions.

What materials are lagoon liners made of?

Clay, synthetic membranes, or compacted soil.

Benefits of riparian buffers other than nutrient reduction?

Provide shade, wildlife habitat, erosion control, and aesthetic value.

Wetlands account for what % of land area in the lower 48 states and in NC?

About 5% nationwide; ~17% in NC.

List four reasons wetlands are important.

Flood control, water filtration, wildlife habitat, carbon storage.

What % of U.S. population lives in coastal areas?

Roughly 50%.

List four common wetland communities in NC.

Cypress swamps, bottomland hardwoods, marshes, pocosins.

List three examples of major anthropogenic wetland alterations.

Draining for agriculture, urban development, channelization.

Difference between wetland restoration and creation.

Restoration = reestablishing former wetland; creation = making new one where none existed.

Name two federal and two state agencies that regulate wetlands.

Federal: EPA & USACE; State (NC): DEQ & WRC.

List two primary indicators of wetland hydrology.

Surface water present and water-stained leaves.

List two secondary indicators of wetland hydrology.

Drift lines and oxidized rhizospheres along roots.

Facultative wetland plants usually occur in wetlands ____ to ____ % of the time.

34-66 %.

A site contains wetland plants when > ____ % of plants are FAC or wetter.

More than 50