Soil Management

Question 1

How do humans influence the soil?

Answer 1

• humans activities create whole new landscapes either immediately or over time
• no humans, no soil

Question 2

Heathland formation

Answer 2

• formed as a result of land use change from human activities
• In Bronze age people cleared large areas of
  woodland for grazing
• continually grazed for centuries
• Turf was removed for fuel
• Nutrients in soil depleted
• Vegetation community adapts to management

Question 3

Agricultural practice and the soil

Answer 3

• successful agriculture relies on a healthy soil
• production and economic pressures cause soil to become used beyond its tolerance
• this leads to various stresses on soil health

Question 4

Various stresses on soil health

Answer 4

• soil compaction
• soil erosion
• soil nutrient depletion
• soil toxicity

Question 5

Types of soil erosion

Answer 5

• Sheet erosion
• Wind erosion
• Rill and Gully
• Splash erosion

Question 6

Rill and gully erosion

Answer 6

• occurs during heavy rains on slopes, forming channels across the landscape

Question 7

Wind erosion

Answer 7

generally less severe than water erosion. it occurs mainly in water-limited systems

Question 8

Sheet erosion

Answer 8

occurs over the soil surface through runoff of large amounts of water losose soil

Question 9

Splash erosion

Answer 9

occurs in areas subject to heavy rainfall. soil is displayed by rain impact

Question 10

How humans cause soil erosion

Answer 10

• over production and organic matter depletion. soil organic matter ‘glue’ to hold aggregates together
• over grazing and associated trampling and vegetation loss
• deforestation and associated loss of cover. no effect of vegetation ‘interception’
• urban land use directly removes soil

Question 11

Soil Nutrient depletion

Answer 11

• tied closely with soil erosion, similar processes to loss
• soil nutrients may be lost through erosion, removal of materials by humans or leaching
• soil nutrient depletion is avoidable but production and economic constraints often force inaction
• soil nutrients may be lost in unfavourable ways

Question 12

Soil nutrient depletion: N

Answer 12

• not all N forms are available to plants.
• N needs to be converted into a plant available form by bacteria or legume plants.
• N that is “locked away” in organic matter is not available (hence the term “immobilization”.
• We need to supply N in its most
  available forms to create a “happy” agro-ecosystem.
• The ratio of N to carbon (C:N ratio) also governs N processing. - So we need to manage these nutrients
  together

Question 13

Soil Toxicity

Answer 13

• soils can become toxic as a result of various human activities e.g.
• mining operations
• industrial activities
• radiation form nuclear incidents
• over application of pest control substances
• acidity and mobility of trace elements
• biological contamination

Question 14

Acidic soils

Answer 14

• depletion of P in acid soils
• enhancement of Fe and Al
• Al toxicity is a major problem in acidic soils
• some parent materials weather to acidic soils
• over application of fertilisers can cause acidity

Question 15

N cycle

Answer 15

• industrial fertilisers do not all enter the N cycle in the same form
• lots of ammonium added to a soil increase the acidity through bacterial and plant uptake trnasformations
• we must be carful about how we manage this problem

Question 16

Principles of sustainable soil use

Answer 16

• an effective soil management system includes the following:
   Management of soil structure and compaction
   Regular monitoring of soil nutrient conditions
   Allowances for the recovery of land and regeneration of
  favourable condition
   Land use with sensitivity to the landscape
   Avoiding reliance on artificial inputs
   Respect for the soil as a full functioning ecosystem

Question 17

Management of compaction

Answer 17

• reduce or avoid cultivation of wet soil
• reduced the use of heavy vehicle son fields and consider traffic patterns
• loosen the top soil regularly
• regularly conduct a check of the subsoil in you fields for sings of compaction, especially after wet weather and during cultivation or harvest

Question 18

Management of leaching

Answer 18

• DEFRA designated nitrate vulnerabel zones in 1996
• these impose limits on nitrate fertiliser amounts and timings
• it also applies to livestock
• these limits are legislated

Question 19

Cultivation practices

Answer 19

• careful water management
• careful timing procedures
• manage soil organic matter

Question 20

Management of salinity

Answer 20

• keep monitoring the soil salinity status
• remove heavily saline topsoil
• controlled leaching
• improve drainage and avoid water logging
• intelligent cultivation patterns
• grow salt tolerant plants
• monitor water use carefully and reduce evaporation
• amendments may be useful
• ensure appropriate drainage
• vegetation cover and increase organic matter

Question 21

Management of acidic soils

Answer 21

• the main way to reduce acidity is to add lime or similar amendments
• ensure lime is added appropriately with good timing and lime quality
• reduce use of fertilisers, especially ammonium based fertilisers
• ensure drainage system in place
• grow acid tolerant crop varieties

Question 22

management of water logging/ gleying

Answer 22

• drainage system such as tile or pipe drainage or drainage channels
• addition of topsoils to clay soils
• grow water-tolerant crops
• increased seeding rate
• ensure adequate N and organic matter status
• consider a change of land use

Question 23

Soil management examples

Answer 23

cover crops
enhances soil structure, 
increase soil organic matter, 
environmental quality 
and improve pest management