PDC Soil Health & Regeneration Techniques 4

Question 1

What is 'terra preta' and why is it significant in permaculture soil design?

Accepted Answer

Ancient Amazonian dark earth created by indigenous people using charcoal and organic waste, still fertile after 2,500 years

Answer

Terra preta is ancient Amazonian dark earth containing biochar, bones, and organic matter, demonstrating that humans can create permanently fertile soils in nutrient-poor environments.

Question 2

In soil remineralization, what is the purpose of applying crushed basalt rock dust?

Accepted Answer

To reintroduce a broad spectrum of trace minerals weathered out of agricultural soils

Answer

Crushed basalt slowly weathers to release a broad spectrum of trace minerals and silica, remineralizing soils depleted by agriculture and mimicking natural geological weathering.

Question 3

What problem does 'soil capping' (surface crusting) cause for water infiltration, and what permaculture practice prevents it?

Accepted Answer

It seals the surface and causes runoff; prevented by keeping soil covered with mulch

Answer

Surface crusting seals pores and causes water to run off rather than infiltrate; permanent mulch cover protects soil structure and maintains infiltration capacity.

Question 4

Which describes the correct layering sequence for a classic 'lasagna' or sheet mulch garden bed from bottom to top?

Accepted Answer

Cardboard → compost → straw → wood chips

Answer

In sheet mulching, cardboard goes directly on soil/grass to smother weeds, followed by compost for nutrients, straw for moisture retention, and wood chips as a top mulch layer.

Question 5

What is the primary ecological function of 'pioneer species' like fireweed (Chamerion angustifolium) on degraded or bare soils?

Accepted Answer

They rapidly colonize bare soil, adding organic matter and creating conditions for subsequent species

Answer

Pioneer species colonize bare or disturbed ground, reduce erosion, add organic matter as they die back, and modify microclimate to enable succession toward more complex communities.

(PDC) Permaculture Design Certification Practice Test

(PDC) Permaculture Design Certification Practice Test

PDC Soil Health & Regeneration Techniques 4