Lal R., Shukla M.K. Principles of Soil Physics
Подождите немного. Документ загружается.
Shrinking, 116
Sieves, 140
Sieving, 37–38, 124
indices to express results of aggregate analysis by, 128
salt, 356
Silica:sesquioxide ratio, 130
Silicon tetrahedron, 52–54
Silt, size fractions of, 35, 36
SI units
abbreviations, 671
prefixes for, 669
Similitude analysis, 657–658
Sinks, 575
Size fractions
of clay, 35
of sand, 34–35, 36
of silt, 35
Skeletal soil, 601–603
Skin seal, 173–174
Slaking, 134
cause of, 168
defined, 407
effects of, 170
factors affecting, 168
field moisture content and, 170
in hardsetting process, 181
Slichter equation, 359
Slump test, 127
Snow gauge, 273
Sodium adsorption ratio (SAR), 422–423
Soil
adhesive versus cohesive forces in, 232
agricultural functions of, 9
agricultural sustainability of, 7–8
agronomic capability of, 4
albedo from, 525
assessing stress-strain behavior in, 190–191
buffering capacity of, 33
cementing agents in, 109–110
cohesion limit of, 238
cohesive strength, 202
color changes as indicator of moisture content, 310
compaction of. See Soil compaction,
as component of ecosystem, 2–3
components of, 5, 15–16, 18
compression of, 208
computing relative density of, 210
computing uniformity coefficient of, 46
consolidation of, 208
for construction purposes, 77
Index 664
contact angle in, 260–261
crack initiation in, 183
in critical state, 237
degradation of, 4–5
degradative processes of, 86
dense verse porous, 22
determining erodibility of, 129, 130
diffusion coefficient in, 471
dispersivity values in, 480
dry, 17
drying process of, 441–443
effect of drying and wetting on, 116–117
effect of freezing on, 117–118
effect of organic component on prop- erties of, 84
effect of puddling on, 179–180
elasticity, 194–195
elastoplastic, 196
engineering functions of, 9
ensuring saturation of, 363–364
environmental functions of, 9
environmental purification functions of, 10–11
estimating hydraulic functions of, 389–402
factors affecting compactibility of, 208–212
field moisture capacity of, 427–428
filtering capacity of, 33
finite resources of, 1
friable consistence of, 232, 233, 236
friction between metal and, 244–245
frictional forces in, 199
functions of, 4
general description of, 1
general physical properties of, 25
general properties of phases and components of, 26
as geomembrane, 10
hardsetting of, 181–183
harsh consistence of, 232, 233
hydrophilic versus hydrophobic, 260–261
hysteresis of, 347–350
hysteretic, 347
impact of decline in soil structure on, 166
importance of porosity to, 149
importance of studying science of, 1
indices for measuring properties of, 129
infiltration rate of, 406
influence on air quality, 11
influence on water quality, 11
initial condition for, 494
inorganic components of. See Inorganic components
interaction with environment. See Pedosphere
interparticle bond forces in, 199
interrelationship among properties of, 25–26
isotropic versus anisotropic, 372
Index 665
isotropism in, 195
liquid consistence of, 233
lower plastice limit of, 238
major stabilizing agents for, 108
measuring dielectric properties of, 305–308
measuring electrical resistance of, 336–337
measuring hydraulic function of, 391
minimizing pore space of, 15
models for sorption, 485–486, 487
moist, 17
moisture content of, 200.
See Soil moisture content
movement of water in, 322
non-homogeneity in, 372
organic compounds in, 77–80
penetration depth of, 310
penetration resistance of, 215–217
phases of, 5, 15–16, 18
plastic consistence of, 233
plasticity of, 195–196, 231, 236–237
porosity of. See Porosity (f
t
)
properties of, 18
quality of. See Soil quality
relation of organic matter with properties of, 85
in relation to plant growth. See Edaphology
removing water from, 299
as reservoir of freshwater, 255
as reservoir of water, 271
saturated, 17
sensitivity of, 95
shape of particles in, 44–47
shear strength of, 197, 198
shrinkage limit of, 237–238
soft consistence of, 232
sticky consistence of, 233
sticky limit of, 238
stress-strain relationship in, 192–193
structural stability of, 110
structureless versus structured, 122
susceptibility to puddling, 179
tensile strength of, 184, 200–202
thermal conductivity of, 308–309
as three-phase system, 259–260
total porosity (f
t
) of, 155
upper plastic limit of, 238
viscoelastic soils, 197
viscosity of. See Viscosity
viscous flow of, 237, 238
void ratio (e) of, 155–156
water absorption capacity of, 68
water infiltration in. See Water infiltration
Index 666
Soil aeration, 563–564
Soil aggegates, 203–204.
See also Aggregate
Soil air, 560–563
composition of, 26
influence on plant growth, 564
O
2
and CO
2
content in, 561
Soil architecture. See Porosity
Soil bulk density, 199, 206–207
methods of measuring, 212–215
pros and cons of methods for measuring, 217
using cold method for, 211
wet versus dry, 213
Soil cohesion (C), 198
Soil colloids
charge distribution, 171
water absorption on, 68–69
Soil compaction, 9, 119
alleviation of, 219, 431
biological measures for preventing, 221, 222–224
causes of, 207–208
defined, 205
in dynamic situation
effect on crop yields, 206, 207, 208, 217–218
expressing degree of, 205
factors affecting, 208–212
farm equipment causing, 208, 209, 210–212
versus hardsetting, 181
influence of texture on, 82
managing in agricultural lands, 217–221
measurement of, 212–217
prevention of, 218–219
relationship between moisture content and, 210
relevance to agriculture, 206
and soil bulk density, 212–215
and soil moisture content, 245–246
in static situation, 205
strategies for management of, 218–221
using penetration resistance to measure, 215
and wheel traffic, 210–212
Soil compressibility, 208
Soil conditioners, 138
Soil consolidation, 221
Soil consistence
attributes of, 232
define, 231–232
forms of, 232–233
impact on soil tilth, 233, 236
Soil Survey Division Staff’s levels of, 233, 234–235
Soil consistency, liquidity index (LI) for, 239–240
Index 667
Soil core, saturating, 363–364
Soil cracking, 183–184
Soil deformation, 199
Soil degradation, 4–5
Soil density (ρ
s
)
bulk density (ρ
b
), 20
dry specific volume (V
b
), 21
particle density, 19–20
relative density, 21
specific gravity (G
s
), 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, 7.
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 668
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 (σ
m
) and immobile (σ
im
), 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 (Φ
m
). 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 669
under field conditions, 331–333
gravitational potential (Φ
z
), 330
matric potential (Φ
m
), 325–329
measuring matric potential (Φ
m
), 333–337
osmotic potential (Φ
o
), 330–331
overburden potential (Φ
o
), 331
plotting profile of, 332
pressure potential (Φ
t
), 324–325
total. See Total soil-moisture potential (Φ
t
)
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, 8
defined, 5, 19
and environmental quality, 10–11
global importance of, 11
interaction with basic and applied sciences, 7
principles of, 5–6
scope of, 16, 19
Soil porosity. See Porosity (f
t
)
Soil properties
oxygen deficiency and, 565–566
surface charge on, 171
susceptible to crusting, 170
Soil quality
and agronomic productivity, 5
defined, 4
elements dependent on, 5
Soil respiration, 566–567
Soil science
and agrosystems, 5
and ecology, 2–3
importance of, 1
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
Index 670
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 671
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 672
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 673