Soil Drainage

Question 1

What does drainage do ?

Answer 1

Removes excess water from soil profile.

Question 2

How is soil drainage done?

Answer 2

By installing network of perforated tubes 60-120cm below soil surface.
Water seeps into small spaces between tubes and drain away .

Question 3

What happens once the water flows into tubing?

Answer 3

Lowers water table to depth of tile.

Question 4

Evidence of how drainage is effective.

Answer 4

Study by Ohio state university demonstrated that for every dollar spent on drainage that grower got back $1.20 and $1.90 when growing corn.

Question 5

How does soil drainage improve soil ?

Answer 5

Better structure.
More friable.
Easier to work with.
Greater root penetration.

Question 6

What does improved aeration mean?

Answer 6

Conditions are more favourable for microorganisms to thrive.

Increasing rate at which organic matter is broken down into humus and plant nutrients mineralised into available form

Question 7

Soil drainages means less compaction. What will this be off?

Answer 7

Heavy machinery.

Grazing.

Question 8

However what is the Disadvantage of inserting drains?

Answer 8

Artificially increase speed of through flow in soil.
Much more water reaches water courses more quickly that before.
Likelihood of flooding increases

Question 9

How can soil drainage impact soil negatively?

Answer 9

Dry top soil subject to wind erosion of not protected.

More wind erosion than water erosion.

Question 10

Where is wind erosion located?

Answer 10

Sandy peaty souls in east anglia/ East Midlands.

Question 11

Where is water erosion more present?

Answer 11

Wales

Question 12

Nitrate loss is another concern, why ?

Answer 12

Lead to eutrophication.
Water draining in fields find way to local water courses.
Enriches ponds with higher nitrogen.
More algae and plant life form.
Disturbs balance of organisms present in water.

Question 13

How to overcome problems of soil drainage?

Answer 13

Use controlled drainage.
Keeps water table high during off season when crops aren’t growing.
More dentrification - nitrate into nitrogen gas.
As soon as saturated soil warms up in spring it reduces nitrate loss

Question 14

Why is soil not water logged?

Answer 14

Water removed from soil quickly.

Question 15

Environment negatives?

Answer 15

Loss of oxygen when eutrophication occurs and death of fish.
Flooding.
Water table lowered

Question 16

Social and economic negative impacts?

Answer 16

damage from flooding.

Cost of implementing and maintaining tubes.