Updated 09/03/13

Optimized Lab Protocols for Testing Soils
By Jared L. DeForest
Department of Environmental and Plant Biology
Ohio University, Athens, OH 45701
Phone: 740-593-0742

email: deforest@ohio.edu

Disclaimer: Most of these methods are modified for testing acidic, fine-texture forest soils commonly found in Eastern Deciduous forests.  Some methods may not directly apply to other soils (e.g. agricultural, calcareous, or sandy soils).  Adjustments in the amount of soil (g) used and standard range might be necessary.    

Sampling & Preparing

Soil Physical Properties
General Soil Chemistry
Soil pH
    Lime Requirement (SMP)
    Organic Carbon (wet combustion)
    Total C and N (elementar)
        CN Standard & Sample Range 
    Exchangeable Acidity & Aluminum

    Extracting for Base Cations - Volumetric
    Extracting for Bioavailable Base Cations - Gravimetric
    Phenolics (microplate)
    Ammonium Analysis (microplate)
    Nitrate Analysis (microplate)  

Soil Phosphorus
Ascorbic Acid Method

    Ascorbic Acid Method - For Anion Exchange Membranes (microplate) 

    Modified Ascorbic Acid Method

The advantage of the modified ascorbic acid method is it does not include orthophosphate derived from the hydrolysis of polyphosphates and/or acid-labile organic P.  If the research question involves just general determination of P, then both methods are fine or use an ICP.  However, if the research question involves determining specifically inorganic ortho-P (e.g. resin P) then the modified method is recommended.      

    Phosphorus Fractions (Hedley Fractionation)  
    Available Phosphorus (Bicarb Extraction, Total and Inorganic)
    Phosphorus Sorption
Microbial Phosphorus

Microbial Fuction & Community
    Phospholipid Fatty Acid (PLFA) Analysis

    Hydrolytic Enzyme Activities 
    Nitrogen Mineralization     

    Litter Fractionations

Major Analytical Equiptment: 
HP 6890 GC-FID w/ autosampler
Synergy HT Multi-Detection Microplate reader