Soil Sampling, Preparation and Analysis

Transcription

1 Soil Sampling, Preparation and Analysis Kim H. Tan The University of Georgia Athens, Georgia Marcel Dekker, Inc. New York* Basel Hong Kong

2 CONTENTS Preface iii Chapter 1 PRINCIPLES OF SOIL SAMPLING General Principles Soil Concept for Sampling Types of Soil Sampling Simple Random Sampling Systematic Sampling Stratified Sampling Compositing Mechanics of Sampling Shallow Sampling Deep Sampling Soil Profile Sampling Time of Sampling Size and Accuracy of Sampling 12 vu

3 viii Chapter 2 SAMPLE PREPARATION Sample Preservation Sample Storage Sample Preparation Grinding and Sieving Grinding Sieving Errors in Grinding and Sieving Reduction in Sample Size 25 Chapter 3 ERRORS AND VARIABILITY OF SOIL ANALYSIS Measure of Accuracy Measure of Precision Measure of Bias Types of Errors Determinate Errors Indeterminate Errors Rejection of Results Checking for Accuracy Checking for Precision Checking for Bias Statement of Results 40

4 ix Chapter 4 METHODS OF SOIL CHEMICAL ANALYSIS Purpose and Use Soil Testing Monitoring Determination of Nutrient Status Plant Testing Tissue Testing Soil Analysis in Pedology and Soil Chemistry Traditional Soil Analysis Isolation and Analysis of Soil Constituents Micropedological Analysis Analysis of Soils in Situ Types of Soil Chemical Analysis Qualitative and Quantitative Analysis 51 Chapter 5 DETERMINATION OF SOIL WATER Definitions and Principles Determination of Total Soil Water Content Direct Determination of Water Content Indirect Determination of Water Content 61

5 5.3 Determination of Available Water Content Pressure-Plate Method Alternative Methods Determination of Soil Moisture Tension 68 Chapter 6 DETERMINATION OF SOIL TEXTURE Definition and Principles Hydrometer Method Dispersion Reagent Procedure Centrifuge Method Reagents Procedure Pipette Method Procedure. 84 Chapter 7 DETERMINATION OF SOIL DENSITY AND POROSITY Definition and Principles Measurement of Bulk Density Bulk Density Measurement of Disturbed Soil 88

6 xi Clod Method Measurement of Particle Density Method Using a Graduated Cylinder Method Using a Volumetric Flask Determination of Pore Spaces 94 Chapter 8 SOIL ph MEASUREMENT Definition and Principles Indicator or Colorimetric Method Potentiometric Method Factors Affecting ph Measurements Suspension Effect Dilution Effect Sodium Effect Water ph Versus Buffer ph Determination of Lime Requirement Determination of Lime Potential 112 Chapter 9 CATION EXCHANGE CAPACITY DETERMINATION Definition and Principles Factors Affecting CEC Determination ph of the Leaching (Displacing) Solution Nature of the Exchange Complex 118

7 xii Nature and Concentration of the Leaching Solution Presence of Undesirable Interactions Analytical Approach Limitations of the Analysis Methods of CEC Determination Ammonium Acetate (NH 4 OAc) Method Alternative Method Determination of ECEC Determination of CEC p Determination of CEC t Methods for Determination of Exchangeable H Barium Chloride-TEA Method Potassium Chloride (KCl) Method 133 Chapter 10 DETERMINATION OF MACROELEMENTS Determination of Soil Nitrogen Forms of Nitrogen in Soils Determination of Total N Kjeldahl Method Determination of Exchangeable NH Determination of NO 3 " Determination of NO 2 '

8 xiii 10.2 Determination of Soil Phosphorus Forms of Phosphorus in Soils Determination of Total P Determination of Organic P Determination of Available P Determination of Potassium Forms of Potassium in Soils Determination of Total K Determination of Available K Determination of Sodium Forms of Sodium in Soils Determination of Total Na Determination of Exchangeable Na Determination of Calcium Forms of Calcium in Soils Determination of Total Ca Determination of Exchangeable Ca Determination of Dilute Acid Soluble Ca Determination of Magnesium Forms of Magnesium in Soils Determination of Total Mg Determination of Exchangeable Mg Determination of Dilute Acid Soluble Mg 182

9 xiv 10.7 Determination of Sulphur Forms of Sulphur in Soils Determination of Total S Determination of Inorganic S 187 Chapter 11 DETERMINATION OF MICROELEMENTS Determination of Aluminum in Soils Forms of Aluminum in Soils Determination of Total Al Determination of Exchangeable Al Determination of Iron in Soils Forms of Iron in Soils Determination of Total Fe Determination of Exchangeable Fe Determination of Available Fe Determination of Free and Amorphous Fe Determination of Silicon in Soils Forms of Silicon in Soils Determination of Total Si Determination of Manganese in Soils Forms of Manganese in Soils Determination of Total Mn Determination of Exchangeable Mn Determination of Available Mn 207

10 xv 11.5 Determination of Copper in Soils Forms of Copper in Soils Determination of Total Cu Determination of Exchangeable Cu Determination of Available Cu Determination of Boron in Soils Forms of Boron in Soils Determination of Total B Determination of Available B Determination of Molybdenum in Soils Forms of Molybdenum in Soils Determination of Total Mo Determination of Available Mo Determination of Zinc in Soils Forms of Zinc in Soils Determination of Total Zn Determination of Exchangeable Zn Determination of Available Zn 222 Chapter 12 DETERMINATION OF SOIL ORGANIC MATTER Definition and Principles Determination of Total Organic C Dry Combustion Method Alternative Method 228

11 xvi 12.3 Determination of Oxidizable Organic C Walkley-Black Wet Combustion Method Determination of Humic Matter Extraction of Soil Humic Matter Extraction of Aquatic Humic Matter Determination of Total Acidity of Humic Matter Determination of Carboxyl and Phenolic-OH Groups 239 Chapter 13 SPECTROPHOTOMETRY AND COLORIMETRY Definition and Principles Absorption Spectrophotometry Principles of Light Absorption Law of Lambert and Bouger Beer's Law Law of Lambert and Beer Visible Light and UV Spectrophotometers Single Beam and Double Beam Spectrophotometers Source of Visible Radiation Source of Ultraviolet Radiation Monochromators Detectors 254

12 xvii Chapter 14 FLAME PHOTOMETRY Definition and Principles Atomic Absorption Spectroscopy Principles of Atomic Absorption Instrumentation Samples and Sample Preparation Interferences Atomic Emission Spectroscopy Principles of Atomic Emission Emission Spectrographic Methods Plasma Emission Spectroscopy Detection Limits of Atomic Absorption and Plasma Emission Spectroscopy 276 Chapter 15 INFRARED SPECTROSCOPY Definition and Principles Origin of Spectra Instrumentation and Sources of Infrared Radiation Primary Source of Radiation Detectors Sample Preparation Gas Samples Liquid Samples Solid Samples 285

13 xvm 15.5 Infrared Analysis of Humic Matter Procedures Infrared Spectra of Humic Matter Methylation of Humic Acids Infrared Analysis of Soil Clays Materials and Pretreatments Procedures Infrared Spectra of Soil Clays 294 Chapter 16 X-RAY DIFFRACTION ANALYSIS Definition and Principles Instrumentation and Principles of X-ray Diffraction Sources of X-ray Radiation Principles of X-ray Diffraction Qualitative X-ray Diffraction Spectrometry Pretreatments Mounting Techniques of Samples in XRD Preparation of Oriented Glass Slide Samples Preparation of Random Powder Samples Diffractograms of Clay Minerals 313

14 xix 16.4 Quantitative X-ray Diffraction Spectrometry Quantitative Interpretations of Diffractograms 328 Chapter 17 DIFFERENTIAL THERMAL ANALYSIS Definition and Principles Instrumentation DTA of Soil Minerals and Organic Matter Sample Preparation Sample Size Sample Packing Furnace Atmosphere Heating Rate Qualitative Interpretation of DTA of Soil Minerals Qualitative Interpretation of DTA of Organic Matter Quantitative Interpretation of DTA of Soil Minerals Preparation of a Standard Curve 360 Appendix A Fundamental Constants 363 Appendix B Greek Alphabet 364 Appendix C Atomic Weights of the Major Elements in Soils 365 Appendix D X-ray Diffraction 26 d-spacing Conversion Table 368

15 xx Appendix E U.S. Weights and Measures 369 Appendix F International System of Units (SI); 371 Factors for Converting U.S. Units into SI Units 371 References and Additional Readings 375 Index 392