SLSC 107--SOIL PHYSICS

• Laosheng Wu
• (Offered in the Spring Quarter Each Year)

Required text:

• Soil Physics, 5th Ed. Jury, Gardner, and Gardner

References:

• Fundamentals of Soil Physics, D. Hillel (1980) (Reserved in Science Library)
• Applied Soil Physics, 2nd Ed J. Hanks

Reading Assignments:

• Chapter 1. Page 1-18; 29-32
• Chapter 2. Page 34-43; 45-65
• Chapter 3. Page 73-89; 94-99; 100-107; 109-112; 114-117
• Chapter 4. Page 122-137; 141-142; 144-147; 150-156
• Chapter 5. Page 159-164; 169-170; 173-192
• Chapter 6. Page 196-213
• Chapter 7. Page 218-233; 255-257

Discussions and Experimental Demonstrations

BASIC PHYSICAL AND MATHEMATICAL RELATIONS

Physical Relations

• F = ma; F = Force (Newton), m = Mass (g, kg), a= Acceleration (m s ^-2)
• W = mg; W = Weight, g = gravitational acceleration (9.8 m s ^-2)
• m = ρV; ρ = density (g cm ^-3), V = Volume
• P = F/A; P = Pressure (pascal = N / m ²), A = Area
• W = FS; W = Work or potential energy (Joule), S = Distance (m)
• P = W/t; P = Power (Joule t ^-1), t = time (s)
• Volume, surface area of objects of various shapes; distance, velocity, and acceleration.

Basic Mathematical Relations

• Powers and Roots
  • a^X a^Y = a ^(X+Y)
  • (ab)^X = a^X b^X
  • a⁰ = 1; (a ≠ 0)
  • (a^X)^Y = a^XY
  • a^X/a^Y = a^(X-Y)
  • (a/b)^X = a^X/b^X
  • a^-X = 1/a^X
  • a^1/X = 
  • a^X/Y = 


• Proportion
  • If a/b = c/d,
        then (a+b)/b = (c+d)/d;    (a-b)/b = (c-d)/d;    (a-b)/(a+b) = (c-d)/(c+d)


• Logarithms and Exponentials
  • e = 2.71828.... is the exponential base.
  • If Y = e^X, then ln (Y) = X
  • e^(X+Y) = e^X e^Y ; e^(X-Y) = e^X /e^Y
  • ln (XY) = ln (X) + ln (Y); ln (X/Y) = ln (X) - ln (Y)
  • (e^X)^Y = e^XY ; ln (X^Y) = Y ln (X)


• Derivatives and Integrals
  • 
  • 
  • 
  • 
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Table of Contents:

• Introduction
• Course objectives and assignments
• Chapter 1. Composition of the soil
  • Three phases of the soil: gas, solid, and liquid
  • Solid phase
    • Primary particles
    • Secondary particles (clay minerals)
    • Soil particles analysis
    • Soil texture classification
    • Characteristics of bulk soil
      • Volume fraction
      • Bulk density: definition and measurement
      • Packing of soil particles
      • Soil structure


• Chapter 2. Water Retention in Soil
  • Properties of water
    • Molecular properties
    • Fluid properties
  • Soil water content
    • Gravitational
    • Volumetric
    • Measurement
  • Energy state of water in soil
    • Potential energy of water in soil
    • Components and total soil-water potential
    • Measurement of components of soil-water potential
  • Water characteristic curves and functions


• Chapter 3. Water Movement in Soil
  • Flow through a capillary tube
  • Saturated water flow
  • Darcy's law and saturated hydraulic conductivity
  • Water flow in saturated soil
    • Gravitational, pressure, and total hydraulic head
    • Flow in horizontal and vertical columns
    • Flow in layered soil
  • Unsaturated water flow - steady state
  • Buckingham-Darcy flux law
  • Unsaturated hydraulic conductivity
  • Water flow in unsaturated soil


• Chapter 4. The Field Soil-Water Regime
  • Field water balance equation
  • Infiltration
  • Water redistribution
  • Evaporation and evapotraspiration
  • Irrigation scheduling principles


• Chapter 5. Solute Transport in Soil
  • Solute conservation equation
  • Mechanisms of solute transport
    • Convective transport
    • Diffusion
    • Hydrodynamic dispersion
  • Convection-dispersion equation
    • Transport of inert, nonadsorbing solutes
    • Transport of inert, adsorbing solutes
    • Reactions of chemicals in soil
    • Effects of soil structure and aggregation on solute transport
  • Non-point source pollution: agricultural practice and groundwater pollution


• Chapter 6. Soil Temperature
  • Soil surface energy balance
  • Thermal properties of soil
  • Heat capacity
  • Thermal conductivity
  • Heat flow in soil
  • Daily and seasonal patterns of soil temperature


• Chapter 7. Soil Aeration
  • Gas transport through soil
    • gas conservation equation
    • gas convection equation
    • gas diffusion
  • Measurement of soil aeration
    • air-filled porosity
    • air permeability
    • diffusion of gases in soil