1. Soil Atmosphere Temperature (Chapter 7)

2. Ch 7 Outline I. Section 7.8: Processes affected by soil temperature II. Section 7.10 – only “soil temperature variations” III. Section 7.11: Soil temperature control

3. I. Soil Temperature – the Process A. Plant processes B. Microbial processes C. Freezing/thawing D. Permafrost E. Heating by fire F. Contaminant removal

4. A. Plant Processes Seed germination Seed germination Root functions Root functions High temps=death/life High temps=death/life Low temps=slow chemical and bio rxns Low temps=slow chemical and bio rxns Narrow range for optimum growth Narrow range for optimum growth Figure 7.18

5. B. Microbial Processes Biological zero=5 o C Biological zero=5 o C Double for each 10 o C rise Double for each 10 o C rise Useful for nutrient mngmt planning/disease control Useful for nutrient mngmt planning/disease control Figure 7.20

6. I. Soil Temperature – the Process A. Plant processes B. Microbial processes C. Freezing/thawing D. Permafrost E. Heating by fire F. Contaminant removal

7. Effects of Fire Figure 7.24

8. II. Thermal properties of soils: temperature fluctuations A. Seasonal B. Vertical C. Daily

9. Seasonal and Vertical Variations Figure 7.31 Note: daily fluctuations lag behind air temperature min and max

10. III. Soil Temperature Control A. Organic residue management=buffer temperature extremes 1. forest floor 2. conservation tillage

11. Tillage Effects C4NQVP Figure 7.34

12. III. Soil Temperature Control A. Organic residue management=buffer temperature extremes 1. forest floor 2. conservation tillage B. Plastic mulches=specialty use 1. generally increase soil temps 2. clear plastic > temp increase than black C. Moisture control 1. more water=lower temps 2. management=improve drainage

13. Review I. Soil Temperature – the Process II. Temperature fluctuations III. Soil Temperature Control

14. Soil Water Chapter 5

15. Chapter 5 Outline I. General Properties of Water I. General Properties of Water II. Capillary Action II. Capillary Action III. Energy Concepts III. Energy Concepts IV. Flow of Water IV. Flow of Water V. Specific Examples V. Specific Examples