Factors affecting soil formation

Question 1

Organisms

Answer 1

Bacteria absorb nitrogen from the air. Creatures (worms) mix and aerate the soil. Decaying plants provide humus for the top soil. Roots bind the soil together.

Question 2

Relief

Answer 2

Steep slopes may limit soil formation through mass movements. Organic decomposition is slower at higher latitudes.

Question 3

Drainage

Answer 3

Gentle slopes (well drained) but steep slopes are prone to erosion and soil creep. Flat areas suffer poor drainage and are liable to waterlogging (gleying).