Soil

Question 1

Why are soils important?

Answer 1

1. Recycle nutrients – carbon, nitrogen, phosphorus
2. Regulate water – rain, snowmelt
3. Filter pollutants – industrial/municipal waste
4. Most importantly - Sustain animal and plant growth

Question 2

How does agriculture affect soil?

Answer 2

Soil horizon mixing by ploughing

Removal of organic matter (crop removal)

Chemicals like pesticides, herbicides and fertiliser kill biota that help
break up the soil

When soil bonds are broken erosion increases

Compaction by machinery

Formation of rills and gullies by tractor wheels

Rotary blades create a plough pan at the bottom of the ploughing
depth which reduces infiltration

Question 3

What are some ways to manage water erosion?

Answer 3

Remove sediment from drains and ditches and return it to the ground

Contour ploughing (across slopes) to prevent rill and gully formation

Stabilise with manure

Plant cover crops to protect the soil (especially in winter)

Decrease runoff from roads

Question 4

Wnat are some ways to manage wind erosion?

Answer 4

Increase soil cohesion with manure

Increase soil roughness by leaving stubble in the fields

Plant hedges and trees to break up the wind. A tree/hedge line has a
wind speed reduction distance of 12x the height

Increase plant cover to intercept rain

Question 5

What are the 2 main types ofsoil erosion?

Answer 5

Water erosion and wind erosion

Question 6

Types of wind erosion

Answer 6

Gully erosion
If rills are not repaired they grow into larger gullies