Soil temperature

Question 1

Processes affected by soil temp

Answer 1

-growth rate, seed germination, root functions
- microbial processes
-freezing/thawing
-soil heating by fire

Question 2

Are plants more sensitive to soil temperature or air temp?

Answer 2

Soil temp

Question 3

Plants that cool soil temp for completion of life cycle

Answer 3

• tulips
• winter wheat, rye

Question 4

Corn seeds planted in soil below 7-10 degree celsius will _____

Answer 4

rot and die

Question 5

Some weed species have Better germination when?

Answer 5

soil temp fluctuates widley

Question 6

What causes winter burn?

Answer 6

Look at notes

Question 7

Biological zero

Answer 7

no biological processes under 5 degree celsius

Question 8

“winter burn”

Answer 8

Air temp is higher then soil temp which causes photorespiration to not be as effective

Question 9

Yellowing or purpling in corn

Answer 9

Low phosphorus uptake

Question 10

Every ___ microbial respiration roughly doubles

Answer 10

10 degree celsius

Question 11

Optimal microbial activity

Answer 11

35-40 degree celsius

Question 12

Nitrification optical around ___ negligible below __

Answer 12

30 degree Celsius 10 degree celsius

Question 13

Freezing and thawing causes ____

Answer 13

improves structure in structureless soils and can degrade structure in well-aggregated soils

Question 14

Frost heaving

Answer 14

Upwards selling of soil during freezing conditions caused by presence of ice as it grows towards the surface

Question 15

Detriments of frost heavings

Answer 15

-pushes up roots
- breaks roads
- pushes pillars out if not placed below frost line

Question 16

Texture of soil less susceptible to heaving

Answer 16

gravel and pure sand

Question 17

Soils more susceptible to heaving

Answer 17

silts and loams

Question 18

burning plant material can create a _______ within soil

Answer 18

water repellent

Question 19

Infiltration rate is ________ in burned areas compared to unburned areas

Answer 19

usually lower

Question 20

After burning what may occur

Answer 20

mudslides

Question 21

Factors that influence soil temp

Answer 21

-climate
-albedo (color)
-slope aspect
-soil cover
-soil moisture

Question 22

Albedo

Answer 22

fraction of incident radiation that is reflected by the land surface

Question 23

Factors that affect soil albedo

Answer 23

-soil color
-surface roughness

Question 24

_______ is the primary source of energy to heat soils

Answer 24

solar radiation