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Task ID:  997  Current maximum soil C% too low for temperate soils    
Created by guest on 2009-08-13 1:35 PM, 3294 days ago
Project:  Module Code
Category:  Minor
Priority:  medium
Assigned to:  hol353  
Status:  closed
Apsim Version:7.0
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 comment 30904 posted by hol353 on 2009-09-18 10:01 AM, 3258 days ago 
I've changed the upper bound to 10 as suggested.
 comment 30756 posted by guest on 2009-08-13 1:35 PM, 3294 days ago 
The current maximum soil C% that is allows before a warning error is produced is 4% (and I think it is hard coded rather than read in).  For temperate soils this causes a warning error for almost all soils that we create – no drama in itself as the model still runs but too many warning errors that do not mean anything just cause the user not to find the real errors.

Can that maximum be increased without compromising finding the input errors the tropical soils?  From Percival etal (2000) the average C% in NZ grassland soils is 4.5% in the top 200 mm (so ‘somewhat’ higher in the top few cm).  

SoilOrder       C% as average across the soil order +1sd
Allophanic    10.3
Brown    6.8
Gley    7.3
Granular    3.7
Melanic    5.1
Oxidic    5.7
Pallic    3.5
Podzols    3.8
Pumice    6.8
Recent    3.8
Semiarid    1.8
Ultic    4.9

My suggestion is that if the upper bound was increased to 10% then most NZ soils would escape the unwanted warning error but it would still capture most AU soils where users entered the C% in g/kg rather than %.

Percival, H.J., R.L. Parfitt, and N.A. Scott, Factors controlling soil carbon levels in New Zealand grasslands: Is clay content important? Soil Science Society of America Journal, 2000. 64: p. 1623–1630.