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Soil Atmosphere. Temperature (Chapter 7). 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. I. Soil Temperature – the Process A. Plant processes
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Soil Atmosphere Temperature (Chapter 7)
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
I. Soil Temperature – the Process A. Plant processes B. Microbial processes C. Freezing/thawing D. Permafrost E. Heating by fire F. Contaminant removal
A. Plant Processes • Seed germination • Root functions • High temps=death/life • Low temps=slow chemical and bio rxns • Narrow range for optimum growth Figure 7.18
B. Microbial Processes • Biological zero=5oC • Double for each 10oC rise • Useful for nutrient mngmt planning/disease control Figure 7.20
I. Soil Temperature – the Process A. Plant processes B. Microbial processes C. Freezing/thawing D. Permafrost E. Heating by fire F. Contaminant removal
Effects of Fire Figure 7.24
II. Thermal properties of soils: temperature fluctuations A. Seasonal B. Vertical C. Daily
Seasonal and Vertical Variations Figure 7.31 Note: daily fluctuations lag behind air temperature min and max
III. Soil Temperature Control A. Organic residue management=buffer temperature extremes 1. forest floor 2. conservation tillage
Tillage Effects C4NQVP Figure 7.34
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
Review I. Soil Temperature – the Process II. Temperature fluctuations III. Soil Temperature Control
Soil Water Chapter 5
Chapter 5 Outline • I. General Properties of Water • II. Capillary Action • III. Energy Concepts • IV. Flow of Water • V. Specific Examples