FIELD BOOK FOR DESCRIBING AND SAMPLING SOILS
SAMPLE COLLECTION AND PREPARATION 1 1 Field Sample Collection and Preparation 1A 1 Site Selection 1A1 1 Geomorphic 1A1a 1 Pedon 1A1b 1 Water 1A1c 1 Biological 1A1d 1 Laboratory Sample Collection and Preparation 1B 16 Soils 1B1 16 Samples 1B1a 16 Bulk 1B1a1 16 Natural Fabrics 1B1a2 17 Clods 1B1a3 17 Cores 1B1a4 17 Preparation 1B1b 17 Field-Moist Preparation 1B1b1 19 Whole Soil 1B1b1a 20 Histosol Analysis 1B1b1a1 20 Biological Analysis 1B1b1a2 20 <2-mm Fraction 1B1b1b 20 Chemical and Selected Physical Analysis 1B1b1b1 20 1500-kPa Water Content 1B1b1b2 20 Field-Field-Moist/Air-dry Ratio 1B1b1b3 21 <2-mm Fraction Sieved to < 0425 mm 1B1b1c 21 Atterberg Limits 1B1b1c1 21 Air-Dry Preparation 1B1b2 21 Whole Soil 1B1b2a 21 Aggregate Stability 1B1b2a1 21 Repository Samples 1B1b2a2 22 <2-mm Fraction 1B1b2b 22 Standard Chemical, Physical, Mineralogical Analysis 1B1b2b1 22 Salt Analysis 1B1b2b2 22 1500-kPa Water Content 1B1b2b3 23 Air-Dry/Oven-Dry Ratio 1B1b2b4 23 Presence of Carbonates 1B1b2b5 23 <2-mm Fraction Sieved to <0425 mm 1B1b2c 23 Atterberg Limits 1B1b2c1 23 <2-mm Fraction Processed to ? 180 ?m 1B1b2d 24 Total Carbon, Nitrogen, and Sulfur 1B1b2d1 24 Carbonates and/or Gypsum 1B1b2d2 24 Chemical Analysis of Organic Materials 1B1b2d3 24 <2-mm Fraction Sieved to 75 ?m 1B1b2e 24 Major and/or Trace Elements 1B1b2e1 24 Particles >2 mm 1B1b2f 24 Particle-Size Analysis 1B1b2f1 25 Particle-Size Analysis, Recorded 1B1b2f1a 25 2- to 20-mm Fraction Processed to <2-mm 1B1b2f1a1 25 Chemical, Physical, and Mineralogical Analysis 1B1b2f1a1a 25 2- to 20-mm Fraction Processed to <2-mm and Recombined 1B1b2f1a2 26 with <2-mm Fraction Chemical, Physical, and Mineralogical Analysis 1B1b2f1a2a 26 Proportion and Particle-Size of Air-Dry Rock Fragments that 1B1b2f1a3 27 Resist Abrupt Immersion in Tap Water Particle-Size Analysis, Not Recorded 1B1b2f1b 25 Whole-Soil Processed to <2-mm 1B1b2f1b1 26 Chemical, Physical, and Mineralogical Analysis 1B1b2f1b1a 26 Water 1B2 29 Samples 1B2a 29 Preparation 1B2b 29 Biological Materials 1B3 30 Samples 1B3a 30 Biology Bulk Sample 1B3a1 30 Microbial Biomass Sample 1B3a2 30 Preparation 1B3b 30 Field-Moist Preparation 1B3b1 30 <2-mm Fraction 1B3b1a 30 Microbial Biomass 1B3b1a1 30 Air-Dry Preparation 1B3b2 30 <2-mm Fraction Sieved <53 ?m, with <53 ?m (C-Mineral) and 1B3b2a 30 > 53 ?m (Particulate Organic Matter) Processed to ? 180 ?m Total Carbon, Nitrogen, and Sulfur Analysis 1B3b2a1 30 <2-mm Fraction 1B3b2b 30 Other Biological Analyses 1B3b2b1 30 Dry (50 C) Preparation 1B3b3 31 Roots 1B3b3a 31 Root Biomass 1B3B3a1 31 Roots Processed to ? 180 ?m 1B3b3a1a 31 Total Carbon, Nitrogen, and Sulfur Analysis 1B3b3a1a1 31 Plants 1B3b3b 31 Plant Biomass 1B3b3b1 31 Plants Processed to ? 180 ?m 1B3b3b1a 31 Total Carbon, Nitrogen, and Sulfur Analysis 1B3b3b1a1 31 CONVENTIONS 2 31 Methods and Codes 2A 31 Data Types 2B 32 Particle-Size Fraction Base for Reporting Data 2C 32 Particles <2 mm 2C1 32 Particles >2mm 2C2 32 Sample Weight Base for Reporting Data 2D 33 Air-Dry/Oven-Dry 2D1 33 Field-Field-Moist/Oven-Dry 2D2 33 Correction for Crystal Water 2D3 33 Significant Figures and Rounding 2E 33 Data Sheet Symbols 2F 33 SOIL PHYSICAL AND FABRIC-RELATED 3 34 ANALYSES Particle-Size Distribution Analysis 3A 34 Particles <2 mm 3A1 34 Pipet Analysis for routinely reported size fractions 3A1a 34 (1, 05, 025, 01, 0047 mm, <20 ?m, and <2 ?m), with or without <02-?m fraction, with or without <2-?m carbonate clay Pipet Analysis with Standard Pretreatments and Dispersion 3A1a1 41 Air-Dry 3A1a1a 41 Field-Moist 3A1a1b 50 Pipet Analysis with Carbonate Removal 3A1a2 46 Air-Dry 3A1a2a 46 Field-Moist 3A1a2b 51 Pipet Analysis with Iron Removal 3A1a3 46 Air-Dry 3A1a3a 46 Field-Moist 3A1a3b 52 Pipet Analysis with Silica Removal 3A1a4 47 Air-Dry 3A1a4a 47 Field-Moist 3A1a4b 53 Pipet Analysis with Ultrasonic Dispersion 3A1a5 47 Air-Dry 3A1a5a 47 Field-Moist 3A1a5b 53 Pipet Analysis with Water Dispersion 3A1a6 48 Air-Dry 3A1a6a 48 Field-Moist 3A1a6b 55 Particles >2 mm 3A2 66 Weight Estimates 3A2a 67 By Field and Laboratory Weighing 3A2a1 67 From Volume and Weight Estimates 3A2a2 70 Volume Estimates 3A2b 70 Bulk Density 3B 73 Saran-Coated Natural Clods 3B1 75 Field State 3B1a 75 33 kPa 3B1b 80 Oven-dry 3B1c 86 Rewet 3B1d 89 Reconstituted 3B2 99 33 kPa 3B2a 99 Oven-Dry 3B2b 99 Compliant Cavity 3B3 98 Field State 3B3a 98 Ring Excavation 3B4 100 Field State 3B4a 100 Frame Excavation 3B5 102 Field State 3B5a 102 Soil Cores 3B6 104 Field State 3B6a 104 Water Retention 3C 105 Pressure-Plate Extraction 3C1 106 6 10, 33, 100, or 200 kPa Water Retention 3C1a-e 106 <2 mm Sieved, Air-Dry 3C1a-e1a 106 Natural Clods 3C1a-d2 108 Soil Cores 3C1a-d3 114 Rewet 3C1c4 117 Reconstituted 3C1c5 121 Pressure-Membrane Extraction 3C2 125 1500 kPa Water Retention 3C2a 125 <2 mm Sieved, Air-Dry 3C2a1a 125 <2 mm Sieved, Field-Moist 3C2a1b 129 Water Retention at Field State 3C3 131 Ratios and Estimates Related to Particle Size 3D 132 Analysis, Bulk Density, and Water Retention Air-Dry/Oven-Dry Ratio 3D1 132 Field-Moist/Oven-Dry Ratio 3D2 132 Correction for Crystal Water 3D3 132 Coefficient of Linear Extensibility 3D4 135 Air-Dry or Oven-Dry to 33-kPa Tension 3D4a 135 Water Retention Difference, Whole Soil 3D5 137 Between 33-kPa and 1500-kPa Tension 3D5a 137 Between 10-kPa and 1500-kPa Tension 3D5b 137 Between 33-kPa and 1500-kPa (Air-Dry) Tension 3D5c 137 1500 kPa Water/Clay Ratio 3D6 138 Total Silt Fraction 3D7 138 Total Sand Fraction 3D8 138 2- to 5-mm Fraction 3D9 138 5- to 20-mm Fraction 3D10 139 20- to 75-mm Fraction 3D11 139 01- to 75-mm Fraction 3D12 139 >2-mm Fraction 3D13 139 Micromorphology 3E 140 Thin sections 3E1 140 Preparation 3E1a 140 Interpretation 3E1b 143 Wet Aggregate Stability 3F 163 Wet Sieving 3F1 163 Air-dry 3F1a 163 2 to 1 mm 3F1a1 163 2- to 05-mm Aggregates Retained 3F1a1a 163 Particle Density 3G 165 Pycnometer Gas Displacement 3G1 165 Oven-dry 3G1a 165 <2 mm 3G1a1 165 >2 mm 3G1a2 165 Atterberg Limits 3H 167 Liquid Limit 3H1 167 Air-Dry, <04 mm 3H1a1 167 Field-Moist, <04 mm 3H1b1 167 Plasticity Index 3H2 167 Air-Dry, <04 mm 3H2a1 167 Field-Moist, <04 mm 3H2b1 167 SOIL AND WATER CHEMICAL EXTRACTIONS 4 167 AND ANALYSES Acid Standardization 4A 167 Ion Exchange and Extractable Cations 4B 173 Displacement after Washing 4B1 173 NH4OAc, pH 7 4B1a 173 Automatic Extractor 4B1a1 173 2 M KCl Rinse 4B1a1a 173 Steam Distillation 4B1a1a1 173 HCl Titration 4B1a1a1a 173 Cation Exchange Capacity (CEC-7) 4B1a1a1a1 173 Air-Dry, <2 mm 4B1a1a1a1a1 173 Field-Moist, <2 mm 4B1a1a1a1b1 173 Atomic Absorption Spectrophotometer 4B1a1b 184 Calcium, Magnesium, Potassium, and Sodium 4B1a1b1-4 184 Air-Dry, <2 mm 4B1a1b1-4a1 184 Field-Moist, <2 mm 4B1a1b1-4b1 184 NH4Cl, Neutral Unbuffered 4B1b 181 Automatic Extractor 4B1b1 181 2M KCl Rinse 4B1b1a 181 Steam Distillation 4B1b1a1 181 HCl Titration 4B1b1a1a 181 Cation Exchange Capacity 4B1b1a1a1 181 Air-Dry, <2 mm 4B1b1a1a1a1 181 Field-Moist, <2 mm 4B1b1a1a1b1 181 Atomic Absorption Spectrophotometer 4B1a1b 188 Calcium, Magnesium, Potassium, and Sodium 4B1b1b1-4 188 Air-Dry, <2 mm 4B1b1b1-4a1 188 Field-Moist, <2 mm 4B1b1b1-4b1 188 BaCl2-Triethanolamine, pH 82 Extraction 4B2 191 Automatic Extractor 4B2a 191 Automatic Titrator 4B2a1 191 Back Titration with HCl 4B2a1a 191 Extractable Acidity 4B2a1a1 191 Air-Dry, <2 mm 4B2a1a1a1 191 Field-Moist, <2 mm 4B2a1a1b1 191 Centrifuge 4B2b 194 Automatic Titrator 4B2b1 194 Back Titration with HCl 4B2b1a 194 Extractable Acidity 4B2b1a1 194 Air-Dry, <2 mm 4B2b1a1a1 194 Field-Moist, <2 mm 4B2b1a1b1 194 1 N KCl Extraction 4B3 197 Automatic Extractor 4B3a 197 Inductively Coupled Plasma Spectrophotometer 4B3a1 197 Radial Mode 4B3a1a 197 Al, Mn 4B3a1a1-2 197 Air-Dry, <2 mm 4B3a1a1-2a1 197 Field-Moist, <2 mm 4B3a1a1-2b1 197 Ratios and Estimates Related to Ion Exchange and 4B4 201 Extractable Cations Sum of Extractable Bases 4B4a 201 Sum of Extractable Bases by NH4OAc, pH 7 4B4a1 201 Sum of Extractable Bases by NH4OAc, pH 7, Calculated 4B4a1a 201 Sum of Extractable Bases by NH4Cl 4B4a2 201 Sum of Extractable Bases by NH4Cl, Calculated 4B4a2a 201 Cation Exchange Capacity (CEC) 4B4b 202 CEC-82 (Sum of Cations) 4B4b1 202 CEC-82, Calculated 4B4b1a 202 CEC-82, Not Calculated 4B4b1b 202 Effective Cation Exchange Capacity (ECEC) 4B4b2 202 Sum of NH4OAc Extractable Bases + 1 N KCl Extractable 4B4b2a 202 Aluminum , Calculated Sum of NH4OAc Extractable Bases + 1 N KCl Extractable 4B4b2b 202 Aluminum , Not Calculated Base Saturation 4B4c 202 Base Saturation by NH4OAc, pH 7 (CEC-7) 4B4c1 202 Base Saturation by CEC-7, Calculated 4B4c1a 202 Base Saturation by CEC-7, Set to 100% 4B4c1b 202 Base Saturation by NH4Cl 4B4c2 203 Base Saturation by NH4Cl, Calculated 4B4c2a 203 Base Saturation by NH4Cl, Set to 100% 4B4c2b 203 Base Saturation by CEC-82 4B4c3 203 Base Saturation by CEC-82, Calculated 4B4c3a 203 Base Saturation by CEC-82, Not Calculated 4B4c3b 203 Base Saturation by ECEC 4B4c4 203 Base Saturation by Sum of NH4OAc Extractable Bases 4B4c4a 203 + 1 N KCl Extractable Aluminum, Calculated Base Saturation by Sum of NH4OAc Extractable Bases 4B4c4b 203 + 1 N KCl Extractable Aluminum, Not Calculated Aluminum Saturation 4B4d 204 Aluminum Saturation by ECEC 4B4d1 204 Aluminum Saturation by Sum of NH4OAc Extractable Bases 4B4d1a 204 + 1 N KCl Extractable Aluminum, Calculated Aluminum Saturation by Sum of NH4OAc Extractable Bases 4B4d1b 204 + 1 N KCl Extractable Aluminum, Not Calculated 204 Activity 4B4e 204 1500-kPa Water/CEC-7 4B4e1 204 Reaction 4C 204 Soil Suspensions 4C1 204 Electrode 4C1a 204 Standard Glass Body Combination 4C1a1 204 Digital pH/Ion Meter 4C1a1a 204 1 N NaF, pH 75 – 78 4C1a1a1 205 Air-Dry, <2 mm 4C1a1a1a1 205 Field-Moist, <2 mm 4C1a1a1b1 205 Saturated Paste pH 4C1a1a2 207 Air-Dry, <2 mm 4C1a1a2a1 207 Oxidized pH 4C1a1a3 209 Organic Materials pH, Final Solution ? 001 M CaCl2 pH 4C1a1a4 211 Combination pH-reference electrode 4C1a2 213 Automatic Titrator 4C1a2a 213 1:1 water pH 4C1a2a1 213 Air-Dry, <2 mm 4C1a2a1a1 213 Field-Moist, <2 mm 4C1a2a1b1 213 1:2 001 M CaCl2 pH 4C1a2a2 213 Air-Dry, <2 mm 4C1a2a2a1 213 Field-Moist, <2 mm 4C1a2a2b1 213 1 M KCl pH 4C1a2a3 215 Air-Dry, <2 mm 4C1a2a3a1 215 Field-Moist, <2 mm 4C1a2a3b1 215 Soil Test Analyses 4D 217 Anion Resin Extraction 4D1 219 Two-Point Extraction 4D1a 219 1 h, 24h, 1 M KCl 4D1a1a1 219 UV-Visible Spectrophotometer, Dual-Beam 4D1a1a1a 219 Phosphorus (2 points) 4D1a1a1a1-2 219 Air-Dry, <2 mm 4D1a1a1a1-2a-b1 219 Field-Moist, <2 mm 4D1a1a1a1-2b1 219 Aqueous Extraction 4D2 223 Single-Point Extraction 4D2a 223 1:10, 30 min 4D2a1 223 UV-Visible Spectrophotometer, Dual Beam 4D2a1a 223 Phosphorus 4D2a1a1 223 Air-Dry, <2 mm 4D2a1a1a1 223 Field-Moist, <2 mm 4D2a1a1b1 223 Flow Injection, Automated Ion Analyzer 4D2a1b 226 Phosphorus 4D2a1b1 226 Air-Dry, <2 mm 4D2a1b1a1 226 Field-Moist, <2 mm 4D2a1b1b1 226 Bray P-1 Extraction 4D3 231 UV-Visible Spectrophotometer, Dual Beam 4D3a 231 Phosphorus 4D3a1 231 Air-Dry, <2 mm 4D3a1a1 231 Field-Moist, <2 mm 4D3a1b1 231 Flow Injection, Automated Ion Analyzer 4D3b 234 Phosphorus 4D3b1 234 Air-Dry, <2 mm 4D3b1a1 234 Field-Moist, <2 mm 4D3b1b1 234 Bray P-2 Extraction 4D4 239 UV-Visible Spectrophotometer, Dual-Beam 4D4a 239 Phosphorus 4D4a1 239 Air-Dry, <2 mm 4D4a1a1 239 Field-Moist, <2 mm 4D4a1b1 239 Olsen Sodium-Bicarbonate Extraction 4D5 242 UV-Visible Spectrophotometer, Dual Beam 4D5a 242 Phosphorus 4D5a1 242 Air-Dry, <2 mm 4D5a1a1 242 Field-Moist, <2 mm 4D5a1b1 242 Mehlich No 3 Extraction 4D6 246 UV-Visible Spectrophotometer, Dual Beam 4D6a 246 Phosphorus 4D6a1 246 Inductively Coupled Plasma Atomic Emission 4D6b 249 Spectrophotometer Axial Mode 4D6b1 249 Ultrasonic Nebulizer 4D6b1a 249 Aluminum, Arsenic, Barium, Calcium, Cadmium, Cobalt, 4D6b1a1-18 249 Chromium, Copper, Iron, Potassium, Magnesium, Manganese, Sodium, Nickel, Phosphorus, Lead, Selenium, and Zinc Air-Dry, <2 mm 4D6b1a1-18a1 249 Field-Moist, <2 mm 4D6b1a1-18b1 249 Citric Acid Soluble 4D7 253 UV-Visible Spectrophotometer, Dual Beam 4D7a 253 Phosphorus 4D7a1 253 Air-Dry, <2 mm 4D7a1a1 253 Field-Moist, < 2 mm 4D7a1b1 253 New Zealand P Retention 4D8 257 UV-Visible Spectrophotometer, Dual Beam 4D8a 257 Phosphorus 4D8a1 257 Air-Dry, <2 mm 4D8a1a1 257 Field-Moist, <2 mm 4D8a1b1 257 1 M KCl Extraction 4D9 260 Cadmium-Copper Reduction 4D9a 260 Sulfanilamide N-1-Naphthylethylenediamine Dihydrochloride 4D9a1 260 Flow-Injection, Automated Ion Analyzer 4D9a1a 260 Nitrate-Nitrite 4D9a1a1-2 260 Air-Dry, <2 mm 4D9a1a1-2a1 260 Field-Moist, <2 mm 4D9a1a1-2b1 260 Field-Moist, <2 mm, Fumigated and Non-fumigated 4D9a1a1-2b2-3 260 Anaerobic Incubation 4D10 265 2 M KCl Extraction 4D10a 265 Ammonia – Salicylate 4D10a1 265 Flow Injection, Automated Ion Analyzer 4D10a1a 265 N as NH3 – Mineralizable N 4D10a1a1 265 Air-Dry, <2 mm 4D10a1a1a1 265 Field-Moist, <2 mm 4D10a1a1b1 265 Carbonate and Gypsum 4E 269 3 N HCl Treatment 4E1 269 CO2 Analysis 4E1a 269 Manometer, Electronic 4E1a1 269 Carbonates 4E1a1a 269 Calcium Carbonate 4E1a1a1 269 Air-Dry, <2 mm 4E1a1a1a1 269 Air-Dry, 2 to 20 mm 4E1a1a1a2 269 Aqueous Extraction 4E2 273 Precipitation in Acetone 4E2a 273 Conductivity Bridge 4E2a1 273 Electrical Conductivity 4E2a1a 273 Gypsum, qualitative and quantitative 4E2a1a 273 Air-Dry, <2 mm 4E2a1a1a1 273 Air-Dry, 2 to 20 mm 4E2a1a1a2 273 Electrical Conductivity and Soluble Salts 4F 277 Aqueous Extraction 4F1 277 1:2 Aqueous Extraction 4F1a 277 Conductivity Bridge 4F1a1 277 Electrical Conductivity 4F1a1a 277 Salt Prediction 4F1a1a1 277 Air-Dry, <2 mm 4F1a1a1a1 277 Saturated Paste 4F2 278 Gravimetric 4F2a 282 Water Percentage 4F2a1 282 Air-Dry, <2 mm 4F2a1a1 282 Conductivity Bridge 4F2b 284 Electrical Conductivity 4F2b1 284 Air-Dry, <2 mm 4F2b1a1 284 Resistivity 4F2b2 286 Air-Dry, <2 mm 4F2b2a1 286 Saturated Paste Extraction 4F2c 289 Automatic Extractor 4F2c1 289 Atomic Absorption Spectrophotometer 4F2c1a 290 Calcium, Magnesium, Potassium, and Sodium 4F2c1a1-4 290 Air-Dry, <2 mm 4F2c1a1-4a1 290 Ion Chromatograph 4F2c1b 294 Conductivity Detector 4F2c1b1 294 Self-Regeneration Suppressor, 4F2c1b1a 294 Bromide, Acetate, Chloride, Fluoride, Nitrate, Nitrite, 4F2c1b1a1-8 294 Phosphate, and Sulfate Air-Dry, <2 mm 4F2c1b1a1-8a1 294 Automatic Titrator 4F2c1c 299 Combination pH-Reference Electrode 4F2c1c1 299 Acid Titration, H2SO4 4F2c1c1a 299 Carbonate and Bicarbonate 4F2c1c1a1-2 299 Air-Dry, <2 mm 4F2c1c1a1-2a1 299 Ratios and Estimates Related to Soluble Salts 4F3 301 Exchangeable Sodium Percentage (ESP) 4F3a 301 ESP, Calculated without Saturated Paste Extraction 4F3a1 301 ESP, Calculated with Saturated Paste Extraction 4F3a2 302 Sodium Adsorption Ratio (SAR) 4F3b 303 Estimated Total Salt 4F3c 303 Selective Dissolutions 4G 303 Dithionite-Citrate Extraction 4G1 307 Atomic Absorption Spectrophotometer 4G1a 307 Aluminum, Iron, and Manganese 4G1a1-3 307 Air-Dry, <2 mm 4G1a1-3a1 307 Field-Moist, <2 mm 4G1a1-3b1 307 Ammonium Oxalate Extraction 4G2 312 Automatic Extractor 4G2a 312 Inductively Coupled Plasma Atomic Emission 4G2a1 312 Spectrophotometer Radial Mode 4G2a1a 312 Aluminum, Iron, Manganese, Phosphorus, and Silicon 4G2a1a1-5 312 Air-Dry, <2 mm 4G2a1a1-5a1 312 Field-Moist, <2 mm 4G2a1a1-5b1 312 UV-Visible Spectrophotometer, Dual Beam 4G2a2 312 Transmittance 4G2a2a 312 Optical Density 4G2a2a1 312 Air-Dry, <2 mm 4G2a2a1a1 312 Field-Moist, <2 mm 4G2a2a1b1 312 Ratios and Estimates Related to Ammonium Oxalate Extraction 4G2b 317 Al + 1?2 Fe 4G2b1 317 Sodium Pyrophosphate Extraction 4G3 317 Atomic Absorption Spectrophotometer 4G3a 317 Aluminum, Iron, and Manganese 4G3a1-3 317 Air-Dry, <2 mm 4G3a1-3a1 317 Field-Moist, <2 mm 4G3a1-3b1 317 Acid Digestion 4G3b 317 K2Cr2O7 + (H2SO4 + H3PO4 Digestion) 4G3b1 317 Nesbitt Bulb 4G3b1 317 CO2 Evolution, Gravimetric 4G3b1a 317 Organic Carbon 4G3b1a1 317 Air-Dry, <2 mm 4G3b1a1a1 317 Field-Moist, <2 mm 4G3b1a1b1 317 Total Analysis 4H 324 Acid Digestion 4H1 324 HNO3 + HCl Digestion 4H1a 324 Microwave 4H1a1 324 Inductively Coupled Plasma Atomic Emission 4H1a1a 324 Spectrophotometer Axial Mode 4H1a1a1 324 Ultrasonic Nebulizer 4H1a1a1a 324 Silver, Arsenic, Barium, Beryllium, Cadmium, Cobalt, 4H1a1a1a1-20 324 Chromium, Copper, Manganese, Molybdenum, Nickel, Phosphorus, Lead, Antimony, Tin, Strontium, Thallium, Vanadium, Tungsten, Zinc Air-Dry, <2 mm 4H1a1a1-20a1 324 HCl Digestion 4H1a1b 331 Water Bath 4H1a1b1 331 Flow through Hydride-Generation and Atomic 4H1a1b1 331 Absorption Spectrophotometer Arsenic and Selenium 4H1a1b1a1-2 331 Air-Dry, <2 mm 4H1a1b1a1-2a1 331 Cold Vapor Atomic Absorption Spectrophotometer 4H1a1c 336 Mercury 4H1a1c1 336 Air-Dry, <2 mm 4H1a1c1a1 336 HF + HNO3 + HCl Digestion 4H1b 341 Microwave 4H1b1 341 Boric Acid 4H1b1a 341 Inductively Coupled Plasma Atomic Emission 4H1b1a1 341 Spectrophotometer Radial Mode 4H1b1a1a 341 Aluminum, Calcium, Iron, Potassium, Magnesium, Manganese, 4H1b1a1a1-11 341 Sodium, Phosphorus, Silicon, Zirconium, Titanium Air-Dry, <2 mm 4H1b1a1a1-11a1 341 Oven-Dry, <2 ?m 4H1b1a1a1-11b2 341 Dry Combustion 4H2 347 Thermal Conductivity Detector 4H2a 347 Carbon, Nitrogen, and Sulfur 4H2a1-3 347 Air-Dry, <2 mm 4H2a1-3a1 347 Ground and Surface Water Analyses 4I 352 Reaction 4I1 352 Electrode 4I1a 352 Standard Glass Body Combination 4I1a1 352 Digital pH/Ion Meter 4I1a1a 352 pH 4I1a1a1 352 Electrical Conductivity and Salts 4I2 353 Conductivity Bridge and Cup 4I2a 353 Electrical Conductivity 4I2a1 353 Atomic Absorption Spectrophotometer 4I2b 355 Calcium, Magnesium, Potassium, and Sodium 4I2b1-4 355 Ion Chromatograph 4I2c 358 Conductivity Detector 4I2c1 358 Self-Regeneration Suppressor 4I2c1a 358 Bromide, Acetate, Chloride, Fluoride, Nitrate, Nitrite, 4I2c1a1-8 358 Phosphate, and Sulfate Automatic Titrator 4I2d 363 Combination pH-reference Electrode 4I2d1 363 Acid Titration, H2SO4 4I2d1a 363 Carbonate and Bicarbonate 4I2d1a1-2 363 Total Analysis 4I3 365 Inductively Coupled Plasma Atomic Emission 4I3a 365 Spectrophotometer Radial Mode 4I3a1 365 Ultrasonic Nebulizer 4I3a1a 365 Aluminum, Iron, Manganese, Phosphorus, and Silicon 4I3a1a1-5 365 ANALYSIS OF ORGANIC SOILS OR MATERIALS 5 368 Mineral Content 5A 368 Pyrophosphate Color 5B 369 Fiber Volume 5C 371 Melanic Index 5D 374 Ratios and Estimates Related to Organic Matter 5E 375 SOIL BIOLOGICAL AND PLANT ANALYSES 6 375 Soil Analyses 6A 375 05 M K2SO4 Extraction + Heating with Disodium 6A1 376 Bicinchoninic Reagent UV-Visible Spectrophotometer, Dual Beam 6A1a 376 Hot Water Extractable Organic Carbon 6A1a1 376 Air-Dry, <2 mm 6A1a1a1 376 002 M KMnO4 Extraction 6A2 379 UV-Visible Spectrophotometer, Dual Beam 6A2a 379 Active Carbon 6A2a1 379 Air-Dry, <2 mm 6A2a1a1 379 Acid Dissolution 6A3 381 1 N HCl Dissolution + FeCl2 6A3a 381 Gas Chromatography 6A3a1 381 CO2 Analysis 6A3a1a 381 Carbonates 6A3a1a1 381 Air-Dry, <2 mm 6A3a1a1a1 381 Particulate Organic Matter and Carbon-Mineral 6A4 385 Total Analysis 6A4a 385 Dry Combustion 6A4a1 385 Thermal Conductivity Detector 6A4a1a 385 Carbon, Nitrogen, and Sulfur 6A4a1a1-3 385 Air-Dry, >53 ?m (POM) 6A4a1a1-3a1 385 Air-Dry, <53 ?m (C-Min) 6A4a1a1-3a2 385 Fumigation Incubation 6B 388 Gas Chromatography 6B1 388 CO2 Analysis 6B1a 388 Soil Microbial Biomass 6B1a1 388 Field-Moist, Whole-Soil 6B1a1a1 388 2 M KCl Extraction 6B2 388 Automatic Extractor 6B2a 388 Ammonia – Salicylate 6B2a1 388 Flow Injection, Automated Ion Analyzer 6B2a1a 388 N as NH3 – Mineralizable N 6B2a1a1 388 Field-Moist, Whole-Soil Fumigated, Whole-Soil 6B2a1a1a1-2 388 Non-Fumigated Plant Analyses 6C 394 Root Biomass 6C1 394 Plant (above-ground) Biomass 6C2 394 Plant Nutrition 6C3 394 Total Analysis 6C3a 394 Dry Combustion 6C3a1 394 Thermal Conductivity Detector 6C3a1a 394 Carbon, Nitrogen, and Sulfur 6C3a1a1-3 394 Dry (50°C), Roots 6C3a1a1-3a1 394 Dry (50°C), Plants (above-ground) 6C3a1a1-3a2 394 Ratios and Estimates Related to Biological Analyses 6E 398 MINERALOGY 7 398 Instrumental Analyses 7A 398 X-Ray Diffraction 7A1 399 Thin Film on Glass, Resin Pretreatment II 7A1a 399 Mg Room Temperature, Mg Glycerol Solvated, K 300°C, 7A1a1 399 K 500°C Thermogravimetric Analysis 7A2 410 Thermal Analyzer 7A2a 410 Differential Scanning Colorimetry 7A3 410 Thermal Analyzer 7A3a 410 Differential Thermal Analysis 7A4 415 Thermal Analyzer 7A4a 415 Surface Area 7A5 418 N2 Adsorption 7A5a 418 Brunauer, Emmett and Teller Theory 7A5a1 418 Vacuum Degassing 7A5a1a 418 Multi-Point 7A5a1a1 418 Air-Dry, <2 mm 7A5a1a1a1 418 Single Point 7A5a1a2 418 Air-Dry, <2 mm 7A5a1a2a1 418 Optical Analyses 7B 422 Grain Studies 7B1 422 Analysis and Interpretation 7B1a 422 Separation by Heavy Liquids 7B1a1 428 Grain Mounts, Epoxy 7B1a2 428 Platy Grains 7B2 434 Magnetic Separation 7B2a 434 Static Tube Separation 7B2b 437 Froth Flotation 7B2c 439 Ratios and Estimates Related to Optical Analysis 7C 442 Total Resistant Minerals 7C1 442 Mineralogy Codes 443