soil fertility quiz 2

Question 1

common soil anions clue (4)

Answer 1

chlorine, nitrate, sulfate, and phosphate

Question 2

CEC and what it depends on

Answer 2

the amount of exchangeable cations per unit dry weight soil, and cec’s depends on the soil texture.

Question 3

CEC- Clay Colloids

Answer 3

Not all clays are alike, most have reporting arrangement of component elements called crystalline structure, others are not well formed crystals and have amorphous structure.

Question 4

CEC Affects many soil processes (4)

Answer 4

• weathering of soil minerals
• nutrient absorption by plants
• leaching of electrolytes
• buffering of soil pH

Question 5

What is buffer capacity?

Answer 5

the ability of a soil to resist change

Question 6

How do labs determine CEC?

Answer 6

CEC is determined by summing the calcium, magnesium, and potassium measured in the soil testing procedure with an estimate of exchangeable hydrogen obtained from the buffer pH

Question 7

What does CEC determine?

Answer 7

How you can supply many important nutrients

Question 8

Management of turf on low CEC soils (4)

Answer 8

• adjusting pH of many soils may adjust CEC
• in most sand based turf systems, CEC comes primarily from organic matter.
• In organic matter, essentially all of the CEC sites are pH dependent with a CEC increase of 10-30% per pH unit.
• If a sand based soil had a pH of 5.0 and lime was applied to raise the pH to 7.o, it may increase CEC.

Question 9

What other sources of OM can be used to increase CEC? (4)

Answer 9

• Zeolite
• Calcined clay
• Nautural Clay
• Resins

Question 10

Two problems with older USGA specs.

Answer 10

Drainage and inconsistent soil mixes were sold.

Question 11

The current USGA spec is less than what % for clay?

Answer 11

3%

Question 12

True or False, resins have a high CEC.

Answer 12

True

Question 13

Characteristics of low CEC soils(7)

Answer 13

• Low nutrient levels
• Rapid changes in nutrient levels
• Leaching
• Salinity build up
• pH changes
• Difficulty in monitoring nutrient status and levels
• Establishment problems

Question 14

Nitrogen management in low CEC soil(4)

Answer 14

• Use of slow release N sources
• Spoonfeeding N with quick release sources.
• Mixture of both is probably best
• Fertigation is another option

Question 15

When is the best time to tell your CEC of your soil?

Answer 15

during construction

Question 16

What does anion exchange capacity do?

Answer 16

Provides sites for negatively charged ions to be retained for plant uptake.