W5 - Topic 10 - Soil Improvement

Question 1

What is soil improvement?

Answer 1

Modifying soil properties to optimize conditions for plant growth.

Question 2

What is the best approach to soil improvement?

Answer 2

Matching plants to existing soil conditions.

Question 3

What are the key components of site analysis?

Answer 3

• Profile Assessment
• Site Considerations

Question 4

What does profile assessment include?

Answer 4

• Topsoil depth
• Texture
• Structure
• pH
• Drainage/aeration
• Compaction

Question 5

What aspects are considered in site considerations?

Answer 5

• Aspect
• Rainfall patterns
• Temperature range
• Existing vegetation

Question 6

What are the symptoms of soil compaction?

Answer 6

Hard soil, poor water infiltration, stunted root growth.

Question 7

What are solutions to soil compaction?

Answer 7

• Decompaction/ripping
• Tillage/cultivation
• Adding organic matter
• Avoiding traffic on wet soils
• Confining traffic to designated areas

Question 8

What are symptoms of poor soil structure?

Answer 8

Hard clods, waterlogging, crusting.

Question 9

What solutions can improve poor soil structure?

Answer 9

• Adding organic matter
• Adding gypsum
• Mixing soil layers
• Cultivating at appropriate moisture content

Question 10

What are symptoms of inadequate topsoil depth?

Answer 10

Shallow rooting, poor plant establishment.

Question 11

What solutions can address inadequate topsoil depth?

Answer 11

• Adding topsoil
• Mounding
• Terracing
• Selecting shallow-rooted plants

Question 12

What symptoms indicate water management issues?

Answer 12

Waterlogging, runoff, water repellence.

Question 13

What solutions are available for water management issues?

Answer 13

• Improving subsurface drainage
• Applying wetting agents
• Decompacting to improve infiltration
• Adjusting irrigation schedules

Question 14

What are the symptoms of pH problems in soil?

Answer 14

Nutrient deficiencies, poor growth.

Question 15

What solutions can be used to adjust soil pH?

Answer 15

• Adding lime to raise pH
• Adding sulfur to lower pH
• Selecting plants adapted to existing pH

Question 16

What symptoms indicate nutrient deficiencies?

Answer 16

Yellowing, stunted growth, poor flowering.

Question 17

What solutions can address nutrient deficiencies?

Answer 17

• Adding appropriate fertilizers
• Incorporating organic matter
• Balancing pH

Question 18

What are the symptoms of salinity issues in soil?

Answer 18

Leaf burn, wilting despite adequate moisture.

Question 19

What solutions can help with salinity issues?

Answer 19

• Improving drainage to leach salts
• Flushing soil with fresh water
• Selecting salt-tolerant plants

Question 20

What are symptoms of disturbed/inverted soil profiles?

Answer 20

Unnatural texture changes, buried organic layers.

Question 21

What solutions can be implemented for disturbed/inverted profiles?

Answer 21

• Mixing layers
• Adding organic matter
• Installing drainage

Question 22

What are the benefits of compost/soil conditioners?

Answer 22

• Improves soil structure
• Increases water-holding capacity
• Enhances nutrient storage
• Stimulates biological activity

Question 23

What is the application guideline for compost?

Answer 23

Apply up to 100mm thick, cultivate into top 200mm of soil.

Question 24

What types of manures are commonly used?

Answer 24

• Cow and sheep
• Chicken
• Horse

Question 25

What is the application guideline for manures?

Answer 25

Use more sparingly than compost (10mm max).

Question 26

What is green manure?

Answer 26

Growing plants specifically to dig into soil.

Question 27

What are the benefits of using green manure?

Answer 27

* Adds organic matter * Improves soil structure * Can fix nitrogen * Suppresses weeds

Question 28

What are the benefits of using mulches?

Answer 28

* Soil insulation * Reduces evaporation * Prevents erosion * Improves infiltration * Suppresses weeds * Adds organic matter over time

Question 29

What are the application guidelines for mulches?

Answer 29

Apply to 75mm maximum depth, keep away from plant stems.

Question 30

What are the requirements for turf?

Answer 30

* Good drainage * Resistance to compaction * Adequate topsoil depth (minimum 100mm, 200mm preferred)

Question 31

What strategies can be employed for annual and vegetable beds?

Answer 31

* Ensure minimum 200mm topsoil depth * Regularly add organic matter * Minimize excessive digging * Implement crop rotation

Question 32

What are the requirements for shrub beds?

Answer 32

* Adequate topsoil depth (300mm minimum) * Good drainage * Appropriate soil structure

Question 33

What are the strategies for trees in soil improvement?

Answer 33

* Select trees suited to site conditions * Decompact large area * Ensure adequate drainage * Consider mounding or terracing * Mulch around trees

Question 34

What is structural soil composed of?

Answer 34

80% rock (20-200mm diameter) and 20% filler soil.

Question 35

What are the limitations of structural soil?

Answer 35

* Low effective soil volume * Drought-prone * Low nutrient content

Question 36

What is the purpose of drainage solutions like agricultural drain pipe?

Answer 36

Removes gravitational water and creates space for excess ground water.

Question 37

What causes perched water tables?

Answer 37

* Finer textured layer over coarser layer * Compacted layers * Hardpans

Question 38

What should be considered in a problem-solving approach for soil improvement?

Answer 38

* Identifying limiting factor(s) * Choosing appropriate intervention * Long-term management

Question 39

What is a practical solution for inadequate topsoil depth for trees?

Answer 39

* Add topsoil * Create mounding * Add subsurface drainage * Consider terracing

Question 40

True or False: The most sustainable approach to soil improvement includes selecting plants well-adapted to existing conditions.

Answer 40

True

Question 41

Fill in the blank: The most sustainable approach often combines modest soil improvements where necessary and _______.

Answer 41

selecting plants well-adapted to existing conditions.