About This calculator provides a platform to estimate the cation exchange capacity (CEC) of neutral and acid soils where direct measurement of CEC is not available from laboratory results. The CEC is calcuated from a combination of soil texture, organic carbon and pH. It can be used in conjunction with LimeMate where a lab test does not include measurement of cations.
  General White cells  in the calcualtor can be edited or changed. Calculations are not saved on exit so if a record is required, print a copy when all input fields have been filled.
  Soil pH Input the pH (CaCl2) - accuracy  of CEC estimate deteriorates for pH greater than 7 and in cracking soils.
  Soil texture Input the soil texture class from your district knowlegde or from soil test value.
  Clay type Cracking clays (2:1) generally have higher CEC tha non-cracking clays (1:1) per unit of clay. Selecting the clay type adjusts the CEC for the dominate clay type. Cracking soils can have a number of clay species present that have large differences in CEC.  More accurate determination of CEC in cracking soils would require a detailed knowledge of clay species present.
  Soil orgainc carbon % Input the soil organic carbon from your from soil test value or district knowlegde.
  Estimated CEC cmol(+)/kg The algorithm to calculate CEC has been developed from standard values for CEC for OC and clay % (texture), clay type and soil pH.  Calculated results showed reasonable agreement with laboratory values for pH<7 in non-cracking soils.
  Disclaimer The evaluation and recommendation reports provided here are a guide only, and depend on representative samples being analysed and a reasonable  estaimate by the user of other inputs. Additionally environmental and managerial factors influence performannce therefore as suppliers of this decision support we do not accept any liability whatsoever arising from the application of recommendations, for any damage, loss or injury of any nature and the user takes these evaluations and recommendations on these terms. This recommendation is made in good faith, based on the best technical information available.
© Back Paddock Company 2016
  BPC CECcalc      
  Input parameters Value    
  Soil pH (CaCl2)    
  Soil texture
  Clay type
  Soil OC %    
  Estimated Clay %    
  Estimated CEC cmol(+)/kg