PDC Sustainable Land Use & Water Management 3 — Questions and Answers
Question 1: Which zoning principle in permaculture most directly reduces water consumption for irrigation?
- Placing high-water-need plants in Zone 5 to mimic natural systems
- Locating water-intensive plants closest to water sources and in Zone 1 (Correct answer)
- Distributing all plants evenly across all zones for aesthetic balance
- Placing drought-tolerant species in Zone 1 for easy access
Correct answer: Locating water-intensive plants closest to water sources and in Zone 1
Placing water-intensive plants near water sources in Zone 1 minimizes transport distance and allows easy, frequent irrigation management.
Question 2: In designing a food forest on a sloped site, where should water-loving trees like willows or alders ideally be planted?
- At the highest ridge to intercept rainfall first
- At the base of slopes or near seasonal water channels (Correct answer)
- Evenly distributed across the entire slope
- On south-facing upper slopes for maximum sun exposure
Correct answer: At the base of slopes or near seasonal water channels
Water-loving species perform best where water naturally accumulates—at slope bases and drainage channels—reducing irrigation needs.
Question 3: What is the main purpose of using a 'broad-base terrace' versus a swale on highly erodible slopes?
- Broad-base terraces allow vehicle traffic and farming across the slope (Correct answer)
- Broad-base terraces require less maintenance than swales
- Swales are better for slopes above 20% grade
- Broad-base terraces are cheaper to construct than swales
Correct answer: Broad-base terraces allow vehicle traffic and farming across the slope
Broad-base terraces have gentle slopes allowing machinery movement and cultivation, unlike swales which are on-contour and not designed for vehicle access.
Question 4: Which practice best describes 'land imprinting' as a soil and water restoration technique?
- Stamping legal land ownership boundaries into official records
- Using a toothed roller to create micro-catchments that trap seeds and rainfall (Correct answer)
- Compacting soil with heavy machinery to reduce runoff
- Applying clay-rich topsoil to degraded land surfaces
Correct answer: Using a toothed roller to create micro-catchments that trap seeds and rainfall
Land imprinting uses a textured roller to create small depressions that capture rainwater and seeds, accelerating revegetation of degraded land.
Question 5: A farm experiences compaction in vehicle trafficked areas. Which permaculture strategy best addresses this over the long term?
- Apply herbicides to reduce plant competition for water
- Establish permanent traffic lanes and plant deep-rooted perennials in no-traffic zones (Correct answer)
- Rototill annually to break up compaction
- Install subsurface drainage pipes throughout the compacted area
Correct answer: Establish permanent traffic lanes and plant deep-rooted perennials in no-traffic zones
Permanent lanes concentrate compaction while perennial deep-rooted plants in protected zones continuously break up and improve soil structure.
Question 6: In tropical permaculture design, which land use strategy best prevents nutrient leaching in heavy rainfall regions?
- Leaving soil bare between crop rows to reduce competition
- Maintaining continuous ground cover with multi-layered vegetation (Correct answer)
- Applying high doses of synthetic fertilizer to compensate for leaching
- Deep plowing before each planting season to expose subsoil nutrients
Correct answer: Maintaining continuous ground cover with multi-layered vegetation
Continuous multi-layered plant cover protects soil, absorbs nutrients before they leach, and cycles them back through biomass decomposition.
Question 7: What does the term 'infiltration rate' measure in soil water management?
- The total volume of water a soil can hold at saturation
- The speed at which water moves downward into the soil profile (Correct answer)
- The percentage of rainfall that becomes surface runoff
- The depth of the water table below the soil surface
Correct answer: The speed at which water moves downward into the soil profile
Infiltration rate measures how quickly water enters the soil, expressed as depth per time (e.g., inches per hour), determining surface runoff potential.
PDC Sustainable Land Use & Water Management 3
Which zoning principle in permaculture most directly reduces water consumption for irrigation?