Laboratory Analysis Soil Fertility Nutrients Lime requirements as a result of buffer capacity high clay soils require more lime than sand soils to raise the pH by one unit Engineering Soil Tests Unified System GP Poorly graded gravel ML Inorganic silts CL Inorganic clays Plastic Index Plastic index equals Liquid limit plastic limit 1 Soil Characterization Tests Physical chemical and mineralogical tests to aid in classifying and interpreting soils Particle size analysis sand silt and clay by weight Bulk density Includes the volume occupied by particles pores and voids Bulk density BD weight of dry soil volume of soil at some specific moisture content Typical range 0 8 to 2 2 g cc g cm 3 2 Particle density Particle density PD weight of dry soil solids volume of soil solids Typically 2 65 g cc g cm 3 Water retention difference Water W 1 3 1 3 bar field capacity Water W 15 15 bar wilting point Water retention difference WRD WRD W 1 3 W 15 BD 1 3 WRD the weight of water in grams retained in 1cc of whole soil between 1 3 bar and 15 bar tension 3 WRD It can be converted to and is usually reported as inches or cm of water per inches or cm of soil Coefficient of linear extensibility COLE relates to shrink swell Thin sections Mineral grain identification Clay films Spodic horizons 4 X ray diffraction Clay mineralogy Soil Porosity Hg intrusion Thin sections Water release and bulk density methods Chemical tests Cation exchange capacity CEC Base saturation Sodium saturation Organic carbon Nitrogen Iron manganese 5 Chemical tests con t Calcium carbonate Chemical Tests con t Sulfur Gypsum Potassium Aluminum Nitrate Extractable acidity Bicarbonate Carbonate Chloride pH Sulfate Phosphorous Calcium and Magnesium 6 7
View Full Document
Unlocking...