Principles of soil physics r lal, m shukla (marcel dekker, 2004)

PRINCIPLES OF SOIL PHYSICS BOOKS IN SOILS, PLANTS, AND THE ENVIRONMENT Editorial Board Agricultural Engineering Robert M.Peart, University of Florida, Gainesville Animal Science Harold Hafs, Rutgers University, New Brunswick, New Jersey Crops Mohammad Pessarakli, University of Arizona, Tucson Environment Kenneth G.Cassman, University of Nebraska, Lincoln Irrigation and Hydrology Donald R.Nielsen, University of California, Davis Microbiology Jan Dirk van Elsas, Research Institute for Plant Protection, Wageningen, The Netherlands Plants L.David Kuykendall, U.S Department of Agriculture, Beltsville, Maryland Kenneth B.Marcum, Arizona State University, Mesa, Arizona Soils Jean-Marc Bollag, Pennsylvania State University, University Park, Pennsylvania Tsuyoshi Miyazaki, University of Tokyo Soil Biochemistry, Volume 1, edited by A.D.McLaren and G.H.Peterson Soil Biochemistry, Volume 2, edited by A.D.McLaren and J.Skujiņš Soil Biochemistry, Volume 3, edited by E.A.Paul and A.D.McLaren Soil Biochemistry, Volume 4, edited by E.A.Paul and A.D.McLaren Soil Biochemistry, Volume 5, edited by E.A.Paul and J.N.Ladd Soil Biochemistry, Volume 6, edited by Jean-Marc Bollag and G Stotzky Soil Biochemistry, Volume 7, edited by G.Stotzky and Jean-Marc Bollag Soil Biochemistry, Volume 8, edited by Jean-Marc Bollag and G.Stotzky Soil Biochemistry, Volume 9, edited by G.Stotzky and Jean-Marc Bollag Soil Biochemistry, Volume 10, edited by Jean-Marc Bollag and G.Stotzky Organic Chemicals in the Soil Environment, Volumes and 2, edited by C A.I.Goring and J.W.Hamaker Humic Substances in the Environment, M.Schnitzer and S.U.Khan Microbial Life in the Soil: An Introduction, T.Hattori Principles of Soil Chemistry, Kim H.Tan Soil Analysis: Instrumental Techniques and Related Procedures, edited by Keith A.Smith Soil Reclamation Processes: Microbiological Analyses and Applications, edited by Robert L.Tate III and Donald A.Klein Symbiotic Nitrogen Fixation Technology, edited by Gerald H.Elkan Soil–Water Interactions: Mechanisms and Applications, Shingo Iwata and Toshio Tabuchi with Benno P.Warkentin Soil Analysis: Modern Instrumental Techniques, Second Edition, edited by Keith A.Smith Soil Analysis: Physical Methods, edited by Keith A.Smith and Chris E Mullins Growth and Mineral Nutrition of Field Crops, N.K.Fageria, V.C.Baligar, and Charles Allan Jones Semiarid Lands and Deserts: Soil Resource and Reclamation, edited by J Skujiņš Plant Roots: The Hidden Half, edited by Yoav Waisel, Amram Eshel, and Uzi Kafkafi Plant Biochemical Regulators, edited by Harold W.Gausman Maximizing Crop Yields, N.K.Fageria Transgenic Plants: Fundamentals and Applications, edited by Andrew Hiatt Soil Microbial Ecology: Applications in Agricultural and Environmental Management, edited by F.Blaine Metting, Jr Principles of Soil Chemistry: Second Edition, Kim H.Tan Water Flow in Soils, edited by Tsuyoshi Miyazaki Handbook of Plant and Crop Stress, edited by Mohammad Pessarakli Genetic Improvement of Field Crops, edited by Gustavo A.Slafer Agricultural Field Experiments: Design and Analysis, Roger G.Petersen Environmental Soil Science, Kim H.Tan Mechanisms of Plant Growth and Improved Productivity: Modern Ap-proaches, edited by Amarjit S.Basra Selenium in the Environment, edited by W.T.Frankenberger, Jr., and Sally Benson Plant–Environment Interactions, edited by Robert E.Wilkinson Handbook of Plant and Crop Physiology, edited by Mohammad Pessarakli Handbook of Phytoalexin Metabolism and Action, edited by M.Daniel and R P.Purkayastha Soil–Water Interactions: Mechanisms and Applications, Second Edition, Re-vised and Expanded, Shingo Iwata, Toshio Tabuchi, and Benno P Warkentin Stored-Grain Ecosystems, edited by Digvir S.Jayas, Noel D.G.White, and William E.Muir Agrochemicals from Natural Products, edited by C.R.A.Godfrey Seed Development and Germination, edited by Jaime Kigel and Gad Galili Nitrogen Fertilization in the Environment, edited by Peter Edward Bacon Phytohormones in Soils: Microbial Production and Function, William T Frankenberger, Jr., and Muhammad Arshad Handbook of Weed Management Systems, edited by Albert E.Smith Soil Sampling, Preparation, and Analysis, Kim H.Tan Soil Erosion, Conservation, and Rehabilitation, edited by Menachem Agassi Plant Roots: The Hidden Half, Second Edition, Revised and Expanded, edited by Yoav Waisel, Amram Eshel, and Uzi Kafkafi Photoassimilate Distribution in Plants and Crops: Source–Sink Relation-ships, edited by Eli Zamski and Arthur A.Schaffer Mass Spectrometry of Soils, edited by Thomas W.Boutton and Shinichi Yamasaki Handbook of Photosynthesis, edited by Mohammad Pessarakli Chemical and Isotopic Groundwater Hydrology: The Applied Approach, Second Edition, Revised and Expanded, Emanuel Mazor Fauna in Soil Ecosystems: Recycling Processes, Nutrient Fluxes, and Agri-cultural Production, edited by Gero Benckiser Soil and Plant Analysis in Sustainable Agriculture and Environment, edited by Teresa Hood and J.Benton Jones, Jr Seeds Handbook: Biology, Production, Processing, and Storage, B.B Desai, P.M.Kotecha, and D.K.Salunkhe Modern Soil Microbiology, edited by J.D.van Elsas, J.T.Trevors, and E.M H.Wellington Growth and Mineral Nutrition of Field Crops: Second Edition, N.K.Fageria, V.C.Baligar, and Charles Allan Jones Fungal Pathogenesis in Plants and Crops: Molecular Biology and Host Defense Mechanisms, P.Vidhyasekaran Plant Pathogen Detection and Disease Diagnosis, P.Narayanasamy Agricultural Systems Modeling and Simulation, edited by Robert M.Peart and R.Bruce Curry Agricultural Biotechnology, edited by Arie Altman Plant–Microbe Interactions and Biological Control, edited by Greg J.Boland and L.David Kuykendall Handbook of Soil Conditioners: Substances That Enhance the Physical Properties of Soil, edited by Arthur Wallace and Richard E.Terry Environmental Chemistry of Selenium, edited by William T.Frankenberger, Jr., and Richard A.Engberg Principles of Soil Chemistry: Third Edition, Revised and Expanded, Kim H Tan Sulfur in the Environment, edited by Douglas G.Maynard Soil–Machine Interactions: A Finite Element Perspective, edited by Jie Shen and Radhey Lal Kushwaha Mycotoxins in Agriculture and Food Safety, edited by Kaushal K.Sinha and Deepak Bhatnagar Plant Amino Acids: Biochemistry and Biotechnology, edited by Bijay K.Singh Handbook of Functional Plant Ecology, edited by Francisco I.Pugnaire and Fernando Valladares Handbook of Plant and Crop Stress: Second Edition, Revised and Ex-panded, edited by Mohammad Pessarakli Plant Responses to Environmental Stresses: From Phytohormones to Ge-nome Reorganization, edited by H.R.Lerner Handbook of Pest Management, edited by John R.Ruberson Environmental Soil Science: Second Edition, Revised and Expanded, Kim H Tan Microbial Endophytes, edited by Charles W.Bacon and James F.White, Jr Plant–Environment Interactions: Second Edition, edited by Robert E.Wil-kinson Microbial Pest Control, Sushil K.Khetan Soil and Environmental Analysis: Physical Methods, Second Edition, Re-vised and Expanded, edited by Keith A.Smith and Chris E.Mullins The Rhizosphere: Biochemistry and Organic Substances at the Soil–Plant Interface, Roberto Pinton, Zeno Varanini, and Paolo Nannipieri Woody Plants and Woody Plant Management: Ecology, Safety, and Envi-ronmental Impact, Rodney W.Bovey Metals in the Environment: Analysis by Biodiversity, M.N.V.Prasad Plant Pathogen Detection and Disease Diagnosis: Second Edition, Revised and Expanded, P.Narayanasamy Handbook of Plant and Crop Physiology: Second Edition, Revised and Expanded, edited by Mohammad Pessarakli Environmental Chemistry of Arsenic, edited by William T.Frankenberger, Jr Enzymes in the Environment: Activity, Ecology, and Applications, edited by Richard G.Burns and Richard P.Dick Plant Roots: The Hidden Half, Third Edition, Revised and Expanded, edited by Yoav Waisel, Amram Eshel, and Uzi Kafkafi Handbook of Plant Growth: pH as the Master Variable, edited by Zdenko Rengel Biological Control of Crop Diseases, edited by Samuel S.Gnanamanickam Pesticides in Agriculture and the Environment, edited by Willis B.Wheeler Mathematical Models of Crop Growth and Yield, Allen R.Overman and Richard V.Scholtz III Plant Biotechnology and Transgenic Plants, edited by Kirsi-Marja OksmanCaldentey and Wolfgang H.Barz Handbook of Postharvest Technology: Cereals, Fruits, Vegetables, Tea, and Spices, edited by Amalendu Chakraverty, Arun S.Mujumdar, G.S Vijaya Raghavan, and Hosahalli S.Ramaswamy Handbook of Soil Acidity, edited by Zdenko Rengel Humic Matter in Soil and the Environment: Principles and Controversies, Kim H.Tan Molecular Host Resistance to Pests, S.Sadasivam and B.Thayumanavan Soil and Environmental Analysis: Modern Instrumental Techniques, Third Edition, edited by Keith A.Smith and Malcolm S.Cresser Chemical and Isotopic Groundwater Hydrology: Third Edition, Emanuel Mazor Agricultural Systems Management: Optimizing Efficiency and Performance, Robert M.Peart and W.David Shoup Physiology and Biotechnology Integration for Plant Breeding, edited by Henry T.Nguyen and Abraham Blum Global Water Dynamics: Shallow and Deep Groundwater, Petroleum Hydrol-ogy, Hydrothermal Fluids, and Landscaping, Emanuel Mazor Principles of Soil Physics, Rattan Lal and Manoj K.Shukla Seeds Handbook: Biology, Production, Processing, and Storage, Second Edition, Revised and Expanded, Babasaheb B.Desai Field Sampling: Principles and Practices in Environmental Analysis, Alfred R.Conklin, Jr Sustainable Agriculture and the International Rice–Wheat System, edited by Rattan Lal, Peter R.Hobbs, Norman Uphoff, and David O.Hansen Plant Toxicology: Fourth Edition, Revised and Expanded, edited by Bertold Hock and Erich F.Elstner Additional Volumes in Preparation PRINCIPLES OF SOIL PHYSICS RATTAN LAL MANOJ K.SHUKLA The Ohio State University Columbus, Ohio, U.S.A MARCEL DEKKER, INC NEW YORK • BASEL Index 668 Soil core, saturating, 363–364 Soil cracking, 183–184 Soil deformation, 199 Soil degradation, 4–5 Soil density (ρs) bulk density (ρb), 20 dry specific volume (Vb), 21 particle density, 19–20 relative density, 21 specific gravity (Gs), 21 units of measurement for, 19 Soil dispersion, 134 Soil drying stages, 441–443 Soil energy balance, 524 Soil erosion, 655 Soil fabric, 96–97 Soil fertility, See also Soil quality Soil fertility management, effects on soil structure, 137–138 Soil friability, 199 Soil infiltration capacity, 406 Soil management, 24 Soil matrix, 24 defined, 33 entry of water into, 406 hydraulic gradient (∆H) across, 357–358 movement of solutes inside See Solute transport pore water velocity through, 359 ratio of smaller to larger pores in, 389–390 total solute resident concentraction (C, g cm−3) unsaturated, 379–380 volumetric flow rate through, 358 Soil minerals, particle density of, 21 Soil moisture ability to suck water from pure water reservoir, 330 characteristics of See Soil moisture characteristics defined, 23 energy status of, 321–322 gravitational potential energy of, 322 presence of solutes in, 330 retention curves for, 344 Soil-moisture capacity function, 387–388 Soil-moisture characteristic curve (SMCC), 390 Soil moisture characteristics computing from relative humidity, 346 defined, 341 factors that affect, 342–344 methods of determining, 345 for soils of contrasting texture, 342 Soil moisture content, 23–24 Index 669 adsorption and desorption of, 347 available water capacity (AWC) of, 293–297 choosing method for measurement of, 312–313 and compaction, 245–246 defined, 287 difficulties in assessing, 297 discontinuity of, 422 in Drop-Cone test, 242 effect of clay minerals on, 241 effect of water infiltration on, 413 expressing rate of change of, 387 expression of measurements of, 312, 314 field capacity (FC) of, 288, 427–428 forces acting on, 287 importance of measuring, 297 least limiting water range of, 294, 296–297 measuring by chemical properties, 311 measuring by dielectric properties of soil, 305–308 measuring by electrical conductivity and capacitance, 300 measuring by evaporation method, 299 measuring by leaching method, 299–300 measuring by low-energy ultrasonic waves, 311 measuring by radiation technique, 300–305 measuring by remote sensing, 309 measuring by thermal conductivity, 308–309 measuring by volume displacement method, 311–312 methods of measurement of, 297–312 mobile (σm) and immobile (σim), 504–506 permanent wilting point (PWP) of, 291–292 principles underlying methods of assessment of, 298 redistribution of, 426–427 relationship to soil-matric potential (Φm) See Soil moisture charac- teristics relationship to soil volume, shrinkage behavior, and soil consistency, 241 relationship to soil water diffusivity, 389 in Richards equation, 386–387 shrinkage limit of, 237–238 in terms of Atterberg’s constants, 237–240 Soil-moisture hysteresis bottleneck effect for, 348 contact angle effect for, 348–349 defined, 347 delayed meniscus formation effect for, 349 entrapped air effect for, 349 entropy effect for, 349–350 importance of, 350 Soil-moisture potential applications of, 350–351 characteristics of, 323 computing components of, 338–341 conversion units for, 352 defined, 322, 323 Index under field conditions, 331–333 gravitational potential (Φz), 330 matric potential (Φm), 325–329 measuring matric potential (Φm), 333–337 osmotic potential (Φo), 330–331 overburden potential (Φo), 331 plotting profile of, 332 pressure potential (Φt), 324–325 total See Total soil-moisture potential (Φt) units of measurement of, 337–341 Soil moisture redistribution, 426–427 Soil-moisture retention, 342, 343 equations for description of, 397 Soil organic carbon (SOC), 79 calculating rate of change of, 80 relationship to agronomic yield, 85 Soil particle density, 27–29 Soil particles See Particles Soil physical quality, 24–25 Soil physics and agricultural sustainability, 6–9 applications of, 7, defined, 5, 19 and environmental quality, 10–11 global importance of, 11 interaction with basic and applied sciences, principles of, 5–6 scope of, 16, 19 Soil porosity See Porosity (ft) Soil properties oxygen deficiency and, 565–566 surface charge on, 171 susceptible to crusting, 170 Soil quality and agronomic productivity, defined, elements dependent on, Soil respiration, 566–567 Soil science and agrosystems, and ecology, 2–3 importance of, Soil scientists, systems used by, 34 Soil separates, 34–37 Soil shrinkage application of, 250 causes of, 246 defined, 246 methods for determining, 248–250 normal, 246–247, 249 670 Index 671 residual, 247–248, 249 Soil slaking See Slaking Soil solids importance of, 80–82 organic fraction and soil processes of, 83 processes in, 33 properties of, 199–200 texture and soil processes of, 82–83 Soil-solute interactions, 477 Soil solution, 26 Soil strength applications of, 197 cohesiveness factor (C) in, 201 and compaction, 245–246 defined, 192, 197 factors affecting, 199–200 indices for measuring, 129 in situ determination of, 203 measurement of, 200–204 measuring modulus of rupture to determine, 202–203 mohr theory of, 198 and penetration resistance, 215 types of, 197 Soil structure, 199 aggregation and structural formation in, 108–114 bonding mechanisms in, 107 classifications according to shape, 123, 125 complexity of, 93–94 crusting and surface seal formation on, 165–167 defined, 93 deformation stresses on, 180–181 degradation of, 134–135 ecological approach to, 95 edaphological approach to, 94–95 effect of added organic matter on, 120–121 effect of decline in, 134 effect of fertility management on, 137 effects of soil conditioners on, 138 effects of structural degradation in, 165, 166, 167, 168 effect of tillage on, 137 effect of water management on, 137 effect of wheel traffic on, 119 elasticity of, 196 endogenous versus exogenous factors in, 115–116 engineering approach to, 95 environmental impacts of, 135–136 factors affecting aggregation in, 115–121 and forces involved in flocculation, 97–99 fractal analyses, 133–134 functional entity of See Porosity indices of, 126, 129–132 Index 672 influence of farming systems on, 136–137 laboratory methods for assessing, 123–124 management of, 135–138 mechanisms of aggregation in, 99–108 methods of assessment for, 121–134 multidisciplinary approach to, 135 pedological approach to, 94 pedological methods for assessing, 122–123 permanent deformation of, 196 pore size distribution of, 156–161 properties of aggregates in, 114 schematic of bonds in, 103 shapes and size classes of, 125 versus soil fabric, 96–97 and soil moisture characteristics, 342–344, 345 structural resiliency of, 132 types of pores in, 94–95 using puddling to improve, 179–181 Zakhrov system of classification of, 122 Soil suction, 386–387 Soil surface, transient evaporation from, 446–447 Soil Survey Division Staff, nine levels of consistence, 233, 234–235 Soil temperature affecting plant growth, 524–525 effect of mulching on, 457, 458 influence on evaporation, 527 management of, 545–554 mean annual, 530–531 optimum range, 525 and properties of water, 527 regimes, 528 variations in, 529–530 varies as a result of, 527–528 Soil temperature classes, 530–531 Soil temperature regimes and the annual cycle, 529–530 categories, 530–531 variations in, 528 Soil texture See Particle size distribution Soil thermal diffusivity, 543 Soil thermal regime, 453 Soil tillage See Tillage Soil tilth See Tilth Soil type, identifying, 122 Soil water field moisture capacity (FC) of, 288–291 plotting characteristic curve of, 401–402 redistribution of, 426–427 Soil-water availability, 527 Soil-water diffusivity, 388–389, 543 Index 673 equation for, 394 mathematical expression of, 449 of wet soil region, 414 Soil water evaporation conditions for, 440 drying of soil during, 441–443 effect of cracks on, 452 example for calculating rates of, 461–462 introduction to, 439–440 from layered soils, 447–448 management of, 452–461 mathematical modeling of stages of drying, 448–452 in presence of water table, 443–446 process of, 440–441 reducing with conservation tillage, 458 reduction of, 452–457, 458, 461 theory of, 443–452 Soil-water movement, 527 Soil water potential, 679 Soil-water profile, 408 Soil water retention models, 396–397 Soil-water storage, 274 Solonetz, 644 Solute flux, 473 Solute flux density, 469–470 Solute input, 474–476 Solutes categories of, 466 piston flow of, 477 presence in soil, 466 pulse application, 476 Solute transport breakthrough curves for, 474–479 combined nondimensional equations for, 496, 497 conditions required for solving equations of, 493–495 dimensional conditions for pulse applications for, 495–496 dispersion processes of, 479–480 displacement of solutes in, 477 equations for, 470–474 equilibrium anion exclusion model for, 486–488 estimating apparent dispersion coeffi- cient for, 502–503 estimating parameters of, 496, 500–507 estimating parameters of two-region model (TRM) for, 503–507 estimating retardation factor (R) for, 500–501 example for calculating, 508–510 Fick’s laws for describing, 469–170 in heterogeneous soils, 488–489 immiscible displacement, 474 influence of displacement length on, 477, 479 introduction to, 465–466 land use effects on, 508 Index 674 mathematical representation of, 482–484 miscible displacement, 474 nondimensional variables for equa- tions of, 497 nonequilibrium, 488 one-dimensional, 490–491 processes of, 466–468 relations between dispersion coefficient and pore water velocity in, 481 sorption phenomenon in, 484–486 step input experiments for, 493–495 two-region anion exclusion model for, 491–492 two-region nonequilibrium model for, 489–491 two-site nonequilibrium model for, 491–492 Solute transport equation, 483 Sorption, 477, 478 models of, 485–486, 487 in solute transport, 484–486 in two-site nonequilibrium transport model, 493 Sorptivity, 416 Sources, 575 Spatial fractals, 133 Specific gravity (Gs), 21 Specific humidity, 269 Specific surface area, 60 of clay minerals, 72 importance of knowing, 47 indices of, 47–48 particle geometry for, 48–50 using adsorption isotherms to deter- mine, 50–52 Specific water capacity, 344 Spherical particles, specific surface area of, 49–50 Sphericity, 47 Spider gauge, 275 “Spirit” thermometer, 516 Sprinkler method, 394–395 for testing water infiltration limits, 406 Stability against water or wind method, 127 Static penetration test, 215 Stationary liquid method, 583–584 Steady flow (v) equation, 373–374 Steady state methods for measurement of KT, 544 for measuring soil’s hydraulic function, 391 Stefan-Boltzmann equation, 519–520 Stefan-Boltzmann law, 531 Step input experiments, 493–495 Stern model, 60–61 Sticky limit, 238 Strain (ε) longitudinal (ε), 192 in Poisson’s ratio (v), 194 Index 675 relationship to stress in soil, 196–197 rhelogical models for, 189–191 shear (γ), 192 time-dependent, 193 in Young’s modulus, 194 Strain hardening, 195–196 Stress (a) acting inside soil body, 202 normal (a), 192 in Poisson’s ratio (v), 194 relationship to strain in soil, 196–197 rhelogical models for, 189–191 tangential (τ), 192 time-dependent, 193 in Young’s modulus, 194 Stokes law, 38, 39, 40 assumptions of, 41 Storage pores, 152, 154 Structural crusts, 167 Structural degradation, environmental effects of, 165, 166, 167, 168 Structural form, 97 Structural pores, 94 Structural porosity, 150 Structural resiliency, 132–133 Structural stability bonding agents for, 110–114 defined, 110 methods of determining, 127 Structured soils, 122 Structured water, 70 Structureless soils, 122 Subirrigation, 589–590 Sublimation, 535 Submergence potential, 324 Subsidence, Subsoil alleviation, 219, 221 Subsoiling, 243 Subsurface flow short-circuiting, 632–633 Suction head, 445 Sulfuric acid solutions, 688 Summation curve, 42, 44, 128 Surface aggregation ratio, 130 Surface area per unit bulk volume (ab), 47 Surface area per unit mass (am), 47 Surface area per unit volume (av), 47 Surface runoff, 406 Surface seal, 169, 170 Surface tension, 158–159, 258–259, 527, 680, 684 Swelling, 116, 637–644 clay and, 639–640 Index cross-linking particles and, 67 curtailing diffused double-layer repulsion in, 68 defined, 66 effect of exchangeable cations on, 66–67 flow in, 642–643 interlattice, 66 interparticle, 66 measurement of, 643–644 models for, 641 pressure potentials in, 640–641 process of, 67 ratio of, 66 stages of, 641–642 Swelling index, 66 Swelling pressure, 638–639 Synthesis cracks, 634–635 Tangential stress (τ), 192, 193 relationship to normal stress (a), 198 Temperature, 515, 684 conversion from one scale to another, 516 and gravelly soils, 617–618 Remote Sensing Thermometer, 519–520 scales for, 516–517 thermocouple, 519 as thermodynamic property, 520–521 Temporary binding agents, 111 Tensile deformation, 204 Tensile strength, 203–204 Tensiometers absolute pressure (P) of, 335 components of, 326 defined, 326 in internal drainage method, 395 limitations of, 329, 333–335 for measuring matric potential (Φm), 333–335 mercury manometer, 326–328 types of, 327 vacuum gauge, 327, 328–329 Tension infiltrometer, 428 Terminal velocity, 39 Terzaghi’s effective stress equation, 202 Textural classes, 42, 43 Textural pores, 94 Textural porosity, 150 Texture agricultural applications of, 84 effect on field moisture capacity (FC), 290 impact on soil, 82–83 soil properties and processes affected by, 83 676 Index soil structure index based on, 131 Thawing, 625 See also Frozen soils and soil physical properties, 630–632 Thermal conductivity (KT), 308–309, 533, 618 of certain metals, 534 defined, 538 effective, 544 of gases, 538 measurement of, 543–545 merits and limitations of, 313 of soil particles, 539 Thermal diffusivity, 539 Thermal expansion, 516 Thermal infrared radiation, 310 Thermalization, 301 Thermal radiation monitoring, 519 Thermic soils, 531 Thermistor, 519 Thermocouples, 519 for the measurement of KT, 544 Thermodynamic potential, 61 Thermodynamic properties, 520–521 Thermodynamics first law of, 521–522 second law of, 522–523 third law of, 522–523 zeroth law of, 521–522 Thermodynamic temperature, 520 Thermoelectric effect, 519 Thermogravimetric method, 299 merits and limitations of, 313 Thermometric liquid, 516 Thermoscope, 515–516 Third law of thermodynamics, 522–523 Thixotropic fluids, 267 Thorburn subsoiling test, 127 Tillage, 118–120, 586 conservation, 458 defined, 456 effect on aggregation, 118–120 effect on soil temperature, 546 effects on soil structure, 137 methods of, 459, 546 reduction of soil water evaporation, 456–457 and soil plasticity, 243–245 and water infiltration, 429, 432–433 Tilth defined, 236 making objective classifications for, 236 677 Index 678 production of, 243 and soil consistence, 233, 236 Time domain reflectometry (TDR), 307–308 merits and limitations of, 313 Time moment analysis, 501 Tortuosity, 468 gas (ξg), 368 of soil pores, 467 water (ξθ), 368 Total porosity (ft), 22, 155 Total soil-moisture potential (Φt) components of, 323–331 under field conditions, 331–333 units of measurement for, 323 Trace gases, importance in Earth’s atmosphere, 559 Transient binding agents, 111–113 Transient evaporation, 446–447 Transient methods for measurement of KT, 544 for measuring soil’s hydraulic function, 391–392 Transmission pores, 152, 154 formation of, 155 Transmission technique, 215 Transverse dispersion, 472 Travel time analysis, 501 Triaxial shearing test, 201–202 Tropical soils, measuring structural sta- bility of, 131 Turbidity/slaking test, 127 Turbulence, 468 Two parallel plate model, 641 Two-region anion exclusion model, 491–492 Two-region model (TRM) parameters, 503–507 Two-site nonequilibrium transport model, 491–492 Unconfined compression test, 202 Uniformity coefficient, 44 Unit conversion factors, 672 Unit conversions, 676 for soil and water potential, 679 Unsaturated flow application of continuity equation to, 384 application of Richards equation to, 386 flux density in, 382 functions of, 379 mechanisms of, 380–382 versus saturated flow, 381 across soil core, 382 total outflow rate of, 385 using Darcy–Buckingham equation to determine, 382–383 Index 679 zone of, 379–380 Unsaturated hydraulic conductivity, 383–384 calculating parameters of, 400–401 calculating with VG equation, 401–402 empirical approaches to estimating, 399–402 measuring with Boltzmann transform method, 393–394 measuring with in situ methods, 394–396 measuring with laboratory methods, 391–393 measuring with soil water retention methods, 396–397 model for predicting, 397–399 relationship to soil porosity, 389–391 Upper plastic limit, 238 in Casagrande test, 242 in Drop-Cone test, 242 indirect methods for measuring, 242–243 Upscaling, 657 Unsteady infiltration, 425–426 Vacuum gauge tensiometer, 327, 328–329 Vadose zone, 379–380, 579 van der Waals forces, 59 colloidal stability and, 172 equation for attractive energy due to, 172 types of, 98 Vane shear test, 203 Vapor density, 269 Vapor in saturated air, 684 Vapor pressure, 268–269, 684 estimating, 411 Vapor-wetting front, 409 Vegetation, 523–524 Vegetative mulch, 453, 454, 456 Vertical flow, 374–375 Vertical infiltration, 416–417 Vertisols, 638 Vesicular-arbuscular (VA) mycorrhizal fungi, 112–113 Viscoelastic fluids, 267 Viscoelastic soil, 197 Viscosity, 527 of fluids, 265–266 kinematic, 265–266 Newton’s law of, 266, 357 of water, 528 Viscosity coefficient, 266 Viscous flow, 237 versus plastic flow, 247 upper limit of, 238 Visible and near infrared spectrum, 310 Void ratio (e), 155, 205 Index 680 range of, 25 Volume displacement method, 311–312 Volumetric compression, measuring resistance to, 197 Volumetric flow rate, 385 equations for, 358 using Poiseulle’s law for, 389 Volumetric heat capacity (Cy), 523 Volumetric inflow rate, 385 Volumetric soil moisture content (Θ), 23–24, 25 Warrick similarity analysis, 658 Water See also Soil water boiling point of, 268–269, 516 change from liquid to vapor, 268 density and viscosity of, 528 density of, 681 entropy of, 257 evaporation from soil See Soil water evaporation flux density of, 471 freezing point of, 516 global distribution of, 255, 256 global transfer rates of, 270 hydrologic cycle of, 269–270 large specific heat of, 98 lysimetric analysis of, 272 measuring in unit quantities, 337 measuring of runoff, 272, 276–278 precipitation of, 272 properties of, 256–269 redistribution into soil, 426–427 six phase changes of, 534–535 soil as reservoir of, 271 solute-free, 466 as soil moisture content See Soil moisture content total potential of, 356 transport to soil surface, 441 viscosity of, 682 types of, 255, 256 Water absorption, 68–69 Water absorption isotherms, 68, 69 Water adsorption, 69–73 Water deficit, 296 Water desorption method, 158–160 Water film theory, 236–237 Water flow, capillary bundle concept of, 356–357 through homogeneous soil profile, 410–411 horizontal, 371 importance of knowing, 355 Index 681 laminar, 359–360 land use effects on, 508 and matric suction (Φm), 380–382 principles of, 356–361 in saturated soils See Saturated flow steady, 373 through 3-dimensional space, 370–372, 384 upward, 445 in unsaturated soils See Unsaturated flow using Darcy’s law to determine, 357–361 vertical, 371 at wetting front, 407–412 Water infiltration calculating depth of, 433 calculating rate of, 433 comparisons of equations for, 421 conceptual models for predicting rates of, 412–418 into crusted soils, 422–423 cumulative, 418, 419 description of, 405–407 empirical models for predicting rates of, 418–420 flux controlled process of, 407–408 and frozen solids, 631–632 and gravelly soil, 614–615 horizontal versus vertical, 415–417 instantaneous rate of, 407–408 into layered soil, 420, 422 management of, 429, 431–434 measurement of, 428–429 from precipitation, 424–425 profile-controlled process of, 408 relation between surface flux and time during, 424 unsteady, 425–426 for water-repellent soil, 653–654 Water management, 137 Water manometer, 327 Water molecules description of, 256–257 electric field of, 257 hydrogen bonding of, 257, 258 surface tension of, 258–259 Water movement See Water flow Water properties at atmospheric pressure, 285 boiling point, 268–269 capillarity, 261–264 contact angle, 259–261 fluidity, 267–268 Newtonian and non-Newtonian fluids, 266–267 osmotic pressure, 264 relevant to soil physical properties and processes, 257 Index 682 solubility of, 265 surface tension, 258–289 vapor pressure, 268–269 viscosity, 266–266 water molecule, 256–258 Water repellency, 651–656 classes, 653 effect of wildfire on, 655 effects on soil processes, 653–655 management of, 656 Water retention in gravelly soils, 610–611 indices for measuring, 129 Water-stable aggregates, 101 Water stage recorder, 276, 277, 430 Water surfaces, albedo for, 524 Water table, management of, 589–590 Water tortuosity (ξθ), 368 Water transmission, 129 Water vapor (H2O), 557 Wet bulk density (ρ′b), 25 Wetting, in water-repellent soils, 652–653 Wetting front defined, 408 on layered soil profiles, 420, 422 movement of vapor ahead of, 411 schematic of depth of, 410 schematic of movement through soils, 410 water movement at, 407–412 Wien’s law, 532 Wier, 277 Wildfires, 655–656 Work-energy principle, 322 Worm holes, 221, 222–223 Yield stress model, 190 Young’s equation, 260 Young’s modulus, 194 Zakhrov system of classification of soil structure, 122 Zeta potential, 61–63 effect of increasing, 64–65 effect of lowering, 64, 65 ... headquarters address above Copyright © 2004 by Marcel Dekker, Inc All Rights Reserved Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical,... influenced by soil particles and chemicals (salt) airborne by wind currents Management of soil structure, control of soil erosion, and restoration of depleted soils are important strategies of mitigating... properties important to the hydrosphere, in terms of the quality and quantity of fresh water resources, are water retention and transmission properties of the soil, surface area and charge properties,