Soils Geography

  1. Chemical Properties of Soil
    1. Soil Reaction and pH
      1. pH Scale and Measurement
        1. Hydrogen Ion Activity
          1. pH Meter Techniques
            1. Indicator Methods
            2. Factors Controlling pH
              1. Parent Material Influence
                1. Leaching Intensity
                  1. Organic Matter Decomposition
                    1. Fertilizer Applications
                    2. pH Effects on Soil Properties
                      1. Nutrient Availability
                        1. Microbial Activity
                          1. Mineral Solubility
                            1. Toxic Element Mobility
                            2. Buffering Mechanisms
                              1. Clay Mineral Buffering
                                1. Organic Matter Buffering
                                  1. Carbonate Buffering
                                    1. Aluminum Buffering
                                  2. Ion Exchange Properties
                                    1. Cation Exchange Capacity
                                      1. Sources of Negative Charge
                                        1. Measurement Methods
                                          1. Typical Values
                                          2. Exchangeable Cations
                                            1. Calcium
                                              1. Magnesium
                                                1. Potassium
                                                  1. Sodium
                                                    1. Aluminum
                                                      1. Hydrogen
                                                      2. Base Saturation
                                                        1. Calculation Methods
                                                          1. Fertility Implications
                                                            1. Climate Relationships
                                                            2. Anion Exchange
                                                              1. Positive Charge Sources
                                                                1. Anion Retention
                                                              2. Soil Salinity and Sodicity
                                                                1. Salinity Measurement
                                                                  1. Electrical Conductivity
                                                                    1. Total Dissolved Solids
                                                                      1. Osmotic Potential
                                                                      2. Sodicity Assessment
                                                                        1. Sodium Adsorption Ratio
                                                                          1. Exchangeable Sodium Percentage
                                                                          2. Salt-Affected Soil Types
                                                                            1. Saline Soils
                                                                              1. Sodic Soils
                                                                                1. Saline-Sodic Soils
                                                                                2. Effects on Plants and Soil
                                                                                  1. Osmotic Stress
                                                                                    1. Ion Toxicity
                                                                                      1. Physical Degradation
                                                                                    2. Soil Colloids and Surface Chemistry
                                                                                      1. Colloidal Properties
                                                                                        1. Surface Area
                                                                                          1. Surface Charge
                                                                                            1. Particle Size
                                                                                            2. Types of Colloids
                                                                                              1. Silicate Clays
                                                                                                1. Oxide Clays
                                                                                                  1. Organic Colloids
                                                                                                  2. Surface Reactions
                                                                                                    1. Adsorption Processes
                                                                                                      1. Precipitation Reactions
                                                                                                        1. Complexation

                                                                                                    Previous

                                                                                                    3. Physical Properties of Soil

                                                                                                    Go to top

                                                                                                    Next

                                                                                                    5. Biological Properties and Soil Organisms