1;Soil Enzymology;3 1.1;Preface;5 1.2;Contents;9 1.3;Contributors;13 1.4;Chapter 1: Soil Enzyme: The State-of-Art;17 1.4.1;1.1 Introduction;17 1.4.2;1.2 Soil: A Physical Point of View;18 1.4.2.1;1.2.1 Particle Shape and Size;18 1.4.2.2;1.2.2 Textural Classes;18 1.4.2.3;1.2.3 Colors;19 1.4.2.4;1.2.4 Density;19 1.4.2.5;1.2.5 Pore Space;19 1.4.2.6;1.2.6 Plasticity and Cohesion;19 1.4.2.7;1.2.7 Soil Temperature and Heat;20 1.4.2.8;1.2.8 Soil Water;20 1.4.3;1.3 Soil: A Chemical Point of View;20 1.4.3.1;1.3.1 Organic Matter;20 1.4.3.2;1.3.2 Humus;21 1.4.3.3;1.3.3 Soil Colloids;21 1.4.4;1.4 Soil: A Biological Point of View;21 1.4.4.1;1.4.1 Kind of Soil Organisms;22 1.4.4.1.1;1.4.1.1 Eubacteria;22 1.4.4.1.2;1.4.1.2 Fungi;24 1.4.4.1.2.1;Decomposers;24 1.4.4.1.2.2;Mutualists;24 1.4.4.1.2.3;Pathogens;24 1.4.4.1.3;1.4.1.3 Algae;25 1.4.4.2;1.4.2 Population Density;25 1.4.4.3;1.4.3 Bacterial Activity;25 1.4.4.3.1;1.4.3.1 Energetics of Nitrification;26 1.4.5;1.5 Enzymes;27 1.4.6;1.6 Soil Enzymes;27 1.4.6.1;1.6.1 Amylase;29 1.4.6.2;1.6.2 beta-Glucosidase;29 1.4.6.3;1.6.3 Cellulase;30 1.4.6.4;1.6.4 Laccase;30 1.4.6.5;1.6.5 Chitinase;31 1.4.6.6;1.6.6 Dehydrogenase;31 1.4.6.7;1.6.7 Phosphatase;32 1.4.6.8;1.6.8 Protease;33 1.4.6.9;1.6.9 Urease;33 1.4.6.10;1.6.10 Arylsulphatase;33 1.4.7;1.7 Conclusion;34 1.4.8;References;34 1.5;Chapter 2: Role of Enzymes in Maintaining Soil Health;40 1.5.1;2.1 Introduction;40 1.5.2;2.2 Soil Enzymes;41 1.5.2.1;2.2.1 Kind of Soil Enzymes;41 1.5.2.1.1;2.2.1.1 Constitutive;41 1.5.2.1.2;2.2.1.2 Inducible;41 1.5.2.2;2.2.2 Origin and State of Soil Enzymes;42 1.5.2.3;2.2.3 Importance of Soil Enzymes;42 1.5.2.4;2.2.4 Application of Soil Enzymes;42 1.5.3;2.3 Soil Health;43 1.5.3.1;2.3.1 Definition;43 1.5.3.2;2.3.2 Aspects of Soil Health;44 1.5.3.3;2.3.3 Interpretation of Soil Health;44 1.5.3.4;2.3.4 Pressures on Soil Health Towards Impacts;45 1.5.4;2.4 Indicators of Soil Health;46 1.5.4.1;2.4.1 Microorganism as Indicators of Soil Health;46 1.5.4.2;2.4.2 Soil Enzymes as Indicators of Soil Health;46 1.5.5;2.5 Potential Roles of Soil Enzymes in Maintaining Soil Health;47 1.5.5.1;2.5.1 Amylase;47 1.5.5.2;2.5.2 Arylsulphatases;48 1.5.5.3;2.5.3 beta-Glucosidase;48 1.5.5.4;2.5.4 Cellulases;49 1.5.5.5;2.5.5 Chitinase;50 1.5.5.6;2.5.6 Dehydrogenase;50 1.5.5.7;2.5.7 Phosphatases;51 1.5.5.8;2.5.8 Proteases;51 1.5.5.9;2.5.9 Urease;52 1.5.6;2.6 Conclusion;52 1.5.7;References;53 1.6;Chapter 3: Agricultural and Ecological Significance of Soil Enzymes: Soil Carbon Sequestration and Nutrient Cycling;58 1.6.1;3.1 Introduction;58 1.6.2;3.2 Soil Enzymes for Organic Matter Decomposition and Nutrient Cycling;59 1.6.2.1;3.2.1 Soil Enzymes of Primary Interest;59 1.6.2.2;3.2.2 Lignocellulolytic Enzymes as Predictors of Organic Matter Decomposition;60 1.6.2.3;3.2.3 Enzymes as Indicators of Soil Nutrient Availability;61 1.6.3;3.3 Microbial Enzyme Production as Affected by Organic Carbon and Nutrient Availability;61 1.6.3.1;3.3.1 Positive and Negative Feedback Mechanisms;61 1.6.3.2;3.3.2 Microbial Resource Reallocation;63 1.6.3.3;3.3.3 Microbial Nutrient Demand;64 1.6.4;3.4 Soil Enzyme Activity in Relation to the Quantity and Quality of Soil Organic Matter;65 1.6.5;3.5 Agricultural and Ecological Significance of Soil Enzymes in Soil Carbon Sequestration;65 1.6.5.1;3.5.1 Assessing Carbon Efflux in Peatlands Under Global Climate Change;65 1.6.5.2;3.5.2 Predicting Soil Carbon Sequestration in Temperate Forests;66 1.6.5.3;3.5.3 Understanding Soil Carbon Storage Potential in Semi-arid Grasslands;69 1.6.5.4;3.5.4 Restoring Soil Organic Matter from the Perspective of Soil Enzymes;70 1.6.6;3.6 Conclusions;71 1.6.7;References;72 1.7;Chapter 4: Enzymes in Forest Soils;76 1.7.1;4.1 Introduction;76 1.7.2;4.2 Distribution of Enzymes in the Soil Profile;77 1.7.3;4.3 Spatial Variability of Enzyme Activities in Soils;78 1.7.4;4.4 Factors Affecting Soil Enzyme Activities;80 1.7.4.1;4.4.1 Producers of Extracellular Enzymes;80 1.7.4.2;4.4.2 Soil Chemistry and Nutrient A