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1.4: Soil Field Methods

  • Page ID
    15133
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    Learning Outcomes:

    Upon completion of this exercise you should be able to:

    • identify master and subordinate horizons in a field setting

    • determine soil physical properties of each horizon in the field

    • complete detailed site and profile descriptions

    Purpose:

    The purpose of this exercise is to provide you with hands-on experience in the field collecting soil profiles by bucket augering and describing site geomorphology and soil profiles.

    Background:

    Fieldwork is an integral part of any soil laboratory exercise since soils must first be collected before they can be analyzed. It is extremely important to ensure that samples are collected as carefully and precisely as possible to reduce errors and eliminate opportunities for sample contamination. It is also important to add a geographic and geomorphic context to your sampling procedures, as they are intimately linked to soil forming factors. Therefore, sample collection is but one component of the fieldwork procedures.

    Soil samples can be collected from a variety of environments using various methods to expose the soil. One common, and often preferred method, is sampling of road cuts since the work of exposing a clean face for sampling has mostly been done for you. Digging a large pit, either by hand or with backhoe, is also common but is either very labor intensive or expensive. The third common method of soil sample collection is by collection through coring. Coring allows you to collect samples for the entire soil profile (or as deep as you can core) without having to expose a face for sampling. All three methods have advantages and disadvantages that you will experience during this exercise.

    Typical Field Equipment:

    • Sturdy boots
    • Bandana
    • Water
    • Shovel
    • Field clothes
    • Camera
    • Pencil
    • Gloves
    • Pocket knife
    • Notebook
    • Hat
    • Pocket tool (i.e. Leatherman)
    • Sample containers
    • Trowel
    • GPS
    • Flagging
    • Soil survey
    • Bucket auger
    • Compass
    • Field Book for Describing and Sampling Soils (Version 3.0)
    • Topographic maps
    • Profile tray
    • Abney level
    • Munsell Color Chart
    • Tape measure
    • Acid bottle

    Exercise: 

    In groups of four you will incrementally collect a soil profile using a bucket auger. Lay samples out in a PVC tray to make a continuous profile. Once a four-foot-long profile has been collected, complete a detailed profile description. You must also complete a detailed site description.

    Use the Field Book for Describing and Sampling Soils (Version 3.0) for an example of how to complete the site and profile description forms and to look-up appropriate codes for the various sections.

     

        Site Description

           Site ID:  Describer(s):  
           Date: Current Weather:  
           Series/Map Unit Name:       Map Unit Symbol:
           Taxonomy:    
           County & State: Lat-Long:      Elevation:
           Avg Annual Temp: Max Temp & Month:      Min Temp & Month:
           Avg Annual Precip: Avg Annual Snow:      Effective Precip
           Slope Aspect: Slope Gradient:  
           Slope Complexity: Slope Shape:  
           Hillslope Profile Position: Geomorph Comp:  
           Land Cover: Parent Material:  
           Landscape/Landform: Soil Moisture Status:  
           Micro features: Another Features:   
           Misc.Notes/Sketch:    

     

        Profile Description ID: 

     

         Horizon 

    Moist Color 

        Depth            (cm)

                Structure                           (grade/size/type)

         Roots and Pores   (Quant./size/location)     Rock and Other Fragments         (kind/size/%vol./roundness)
            1            
            2            
            3            
            4            
            5            
            6            

     

     

          Horizon

      Boundary (Distinctness)

        Consistence 

      Texture

      Misc.Notes (e.g., redox features, concentrations, etc.)

            1          
            2          
            3          
            4          
            5          
            6          

     

     


    1.4: Soil Field Methods is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Mark W. Bowen via source content that was edited to conform to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.