Soil Chemistry, 5th Edition

DANIEL G. STRAWN, PHD, is a professor at the University of Idaho.
HINRICH L. BOHN, PHD, is Professor Emeritus, at the University of Arizona.
GEORGE A. O'CONNOR, PHD, is Professor Emeritus, at the University of Florida.

Preface to Fifth Edition xii
Preface to Fourth Edition xiii
Acknowledgments xiv
1 Introduction to Soil Chemistry 1
1.1 The soil chemistry discipline 1
1.2 Historical background 3
1.3 The soil environment 6
1.4 Chemical reactions in soils 15
1.5 Soil biogeochemical cycling 22
1.6 Soil chemical influences on food production 22
1.7 Soils and environmental health 23
1.8 Units in soil chemistry 26
1.9 Summary of important concepts in soil chemistry 26
2 Properties of Elements and Molecules 31
2.1 Introduction 31
2.2 Ionization and ionic charge 33
2.3 Ionic radius 33
2.4 Molecular bonds 36
2.5 Nature of water and hydration of ions 37
2.6 Ligands and metal bonds 40
2.7 Summary of important concepts of elemental and molecular properties 42
3 Characteristics of Chemicals in Soils 43
3.1 Introduction 43
3.2 Occurrence of elements in soils 43
3.3 Essential elements 47
3.4 Inorganic contaminants in the environment 49
3.5 Anthropogenic organic chemicals in the soil environment 53
3.6 Properties of the elements in soils 58
3.7 Summary of important concepts for chemicals in the soil environment 75
4 Soil Water Chemistry 77
4.1 Introduction 77
4.2 Thermodynamic approach to aqueous soil chemistry 78
4.3 Calculation of ion activity 83
4.4 Acids and bases 86
4.5 Gas dissolution 89
4.6 Precipitation and dissolution reactions 91
4.7 Cation hydrolysis 102
4.8 Complexation 105
4.9 Using software to predict soil solution equilibrium 110
4.10 Kinetics of chemical reaction in soil solution 111
4.11 Summary of important concepts for soil solution chemistry 116
5 Redox Reactions in Soils 119
5.1 Introduction 119
5.2 Redox reactions in nature 121
5.3 Basic approaches for characterizing soil redox processes 126
5.4 The role of protons in redox reactions 133
5.5 Redox potential limits in natural systems 133
5.6 pe-pH diagrams 135
5.7 Prediction of oxidation and reduction reactions in soils 137
5.8 Redox measurement in soils 141
5.9 Soil redoximorphic features and iron reduction in wetlands 142
5.10 Nitrogen redox reactions in soils 144
5.11 Summary of important concepts in soil redox reactions 147
6 Mineralogy and Weathering Processes in Soils 150
6.1 Introduction 150
6.2 Common soil minerals 152
6.3 Crystal chemistry of minerals 153
6.4 Common primary mineral silicates in soils 161
6.5 Minerals and elements in rocks 164
6.6 Stability of silicates to weathering 165
6.7 Chemistry of soil weathering and mineral formation 167
6.8 Formation of secondary minerals in soils 170
6.9 Soil carbonates 174
6.10 Evaporites 176
6.11 Soil phosphate minerals 177
6.12 Sulfur minerals 177
6.13 Time sequence of mineral formation in soils 178
6.14 Measurement of soil mineralogy 180
6.15 Important concepts in soil mineralogy 184
7 Chemistry of Soil Clays 186
7.1 Introduction 186
7.2 Structural characteristics of phyllosilicates 187
7.3 Relation of phyllosilicate structure to physical and chemical properties 193
7.4 Detailed properties of phyllosilicates 199
7.5 Allophane and imogolite 204
7.6 Zeolite 205
7.7 Oxide minerals 205
7.8 Summary of soil clays 210
8 Production and Chemistry of Soil Organic Matter 214
8.1 Introduction 214
8.2 Ecosystem carbon storage and fluxes 217
8.3 Soil organic matter formation factors 219
8.4 Organic chemistry of SOM 221
8.5 Plant and microbial compounds input into soil 223
8.6 SOM decay processes 225
8.7 SOM composition and structure 229
8.8 NaOH extraction of SOM 231
8.9 Function of organic matter in soil 233
8.10 Summary of SOM 237
9 Surface Properties of Soil Colloids 240
9.1 Introduction 240
9.2 Permanent charge 240
9.3 pH?]dependent charge 241
9.4 Point of zero charge of variable charged surfaces 247
9.5 pH?]dependent charge of SOM 250
9.6 Hydrophobic regions of soil organic matter 252
9.7 Summary of important concepts in soil surface charge 252
10 Adsorption Processes in Soils 255
10.1 Introduction 255
10.2 Physical model of charged soil particle surfaces 260
10.3 Cation exchange on soils 266
10.4 Inner?]sphere adsorbed cations 273
10.5 Anion adsorption 281
10.6 Adsorption of anthropogenic organic chemicals in soils 286
10.7 Summary of important concepts for adsorption and desorption reactions in soils 292
11 Measuring and Predicting Sorption Processes in Soils 296
11.1 Introduction 296
11.2 Adsorption experiments 296
11.3 Predicting adsorption using empirical models 297
11.4 Predicting adsorption using mechanistic models 300
11.5 Rates of adsorption 304
11.6 Reactive transport 306
11.7 Surface precipitation 309
11.8 Analytical methods for determining adsorption mechanisms 310
11.9 Summary of important concepts for modeling surface reactions in soils 311
12 Soil Acidity 314
12.1 Introduction 314
12.2 History of soil acidity 317
12.3 The role of aluminum in soil pH 318
12.4 Base cations in soil solutions 319
12.5 Soil acidification processes 321
12.6 Aluminum and manganese toxicity 326
12.7 Plant nutrients in acid soils 327
12.8 Managing acidic soils 327
12.9 Summary of important concepts in soil acidity 329
13 Salt?]affected Soils 331
13.1 Introduction 331
13.2 Distribution and origin of salt?]affected soils 331
13.3 Characterization of salinity in soil and water 334
13.4 Describing salt?]affected soils 340
13.5 Effects of salts on soils and plants 341
13.6 Salt balance and leaching requirement 343
13.7 Reclamation 344
13.8 Summary of important concepts in soil salinity 345
Questions 345
Bibliography 346
Index 347