PDC Sustainable Land Use & Water Management 5 â Questions and Answers
Question 1: What is the ecological benefit of 'mulching' bare soil in permaculture water management?
- It increases soil temperature to accelerate evaporation
- It reduces evaporation, moderates soil temperature, and suppresses weeds while building organic matter (Correct answer)
- It prevents beneficial soil organisms from accessing the surface
- It compacts the soil surface to reduce water penetration
Correct answer: It reduces evaporation, moderates soil temperature, and suppresses weeds while building organic matter
Mulch creates a protective layer that retains soil moisture, regulates temperature, feeds soil life, and suppresses weed competition.
Question 2: A designer notices a 'hydric soil'âdark, mottled, and anaerobicâduring a site survey. What does this indicate about the land's hydrology?
- The site has excellent drainage and high water infiltration
- The site experiences seasonal or permanent waterlogging or saturation (Correct answer)
- The soil has been recently tilled and disturbed
- The site is located on a well-drained ridge position
Correct answer: The site experiences seasonal or permanent waterlogging or saturation
Hydric soils form under prolonged waterlogged, anaerobic conditions and indicate a wetland or frequently saturated landscape position.
Question 3: In permaculture, 'sector analysis' related to water management primarily involves identifying what?
- The financial sectors where water investment should be allocated
- Natural water flows, flood zones, drought-prone areas, and seasonal water patterns on the site (Correct answer)
- The agricultural sectors where irrigation infrastructure will be installed
- Government water rights sectors that legally govern land use
Correct answer: Natural water flows, flood zones, drought-prone areas, and seasonal water patterns on the site
Sector analysis maps external natural energiesâincluding water movement, flooding, and drought patternsâto inform design placement decisions.
Question 4: Which cover crop characteristic is most valuable for improving water infiltration on compacted or degraded soils?
- Fast above-ground biomass production for mulch
- Deep or fibrous root systems that break up compaction and create biopores (Correct answer)
- High nitrogen fixation rates to replace synthetic fertilizers
- Rapid seed production for self-seeding perennial establishment
Correct answer: Deep or fibrous root systems that break up compaction and create biopores
Deep taproots (like daikon radish) and dense fibrous roots physically break compaction layers and leave biopores that improve water movement through the soil profile.
Question 5: What is the primary land management advantage of 'mob grazing' or 'adaptive multi-paddock grazing' in permaculture systems?
- It allows continuous grazing of the same paddock for maximum efficiency
- It mimics natural herd migration, allowing long recovery periods that restore soil and vegetation (Correct answer)
- It reduces animal feed requirements by limiting movement
- It eliminates the need for fencing infrastructure
Correct answer: It mimics natural herd migration, allowing long recovery periods that restore soil and vegetation
Mob grazing replicates natural herd behavior with intense short grazing followed by long rest periods, rebuilding soil carbon, root depth, and water infiltration.
Question 6: Which concept describes the practice of designing land so that each element serves multiple functions in the water cycle?
- Monoculture efficiency
- Stacking functions (Correct answer)
- Linear production systems
- Compartmentalized management
Correct answer: Stacking functions
Stacking functions means each design element (e.g., a pond) serves multiple roles: water storage, microclimate moderation, aquaculture, and fire protection.
Question 7: A permaculture designer is restoring a degraded watershed with severely eroded gullies. Which intervention sequence is most appropriate?
- Plant trees first, then install erosion control structures once established
- Install check dams and rock structures to slow water, then revegetate with pioneer plants (Correct answer)
- Apply chemical soil stabilizers, then seed with annual grasses
- Construct large retention ponds at gully heads to capture all runoff immediately
Correct answer: Install check dams and rock structures to slow water, then revegetate with pioneer plants
Check dams immediately slow water velocity and trap sediment, creating stable conditions for pioneer plants to revegetate and heal the gully system.
PDC Sustainable Land Use & Water Management 5
What is the ecological benefit of 'mulching' bare soil in permaculture water management?