08/1491 - MCU - Detached House [As Published] · 132008.1491

~

o

 

Chromium Suite: The acid base accounting approach used to calculate net acidity which uses the chromium reducible sulfur mathod to determine potential
sulfidic acidity. A decision tree approach based on the pHKCI result is then used to determine the other components of the acid base account.

CIN: tnorganic carbon, (CT -CTo}. It is used to estimate the carbonate content of the soil. CRS: Tha acronym often given to the Chromium Reducible Sulfur
method.

CT: Total carbon. A measure of the total carbon content of the soil, encompassing both organic and
inorganic forms.

CTo: Total organic carbon. The carbon in sample measured following a sulfurous acid digestion procedure used to remove carbonate carbon.

Existing Acidity: The acidity already present in acid sulfate soils, usually as a result of oxidation of sulfides, but which can also be from organic material or
acidic cations, it can be further sub- divided into actual and retained acidlty, ie. Existing Acidity = Actual Acidity + Retalned Acidity.

Fineness factor: A factor applied to the acid neutralising capacity resultin the acid base account to allow for the poor reactivity of coarser carbonate or other
acid neutralising material. The minimum factor Is 1.5 for flnely divided pure agricultural lime, but may be as high as 3.0 for coarser shell material.

MgA; Reacted magnesium. Tha magnesium soluble after the peroxide digest and TPA titration that was not soluble following KC1-extraction and T AA titration.
(Mgp -MgKCl. It can be used (in combination with CaA) to provide an estimate of the soil carbonate content, but may be an underestimate If the HCi-titration

eS 4 has not been performed as part of the TPA/ANC, procedure.

MgHCt: Magnesium soluble in 4 M HCl, which Includes soluble and exchangeable magnesium as wall as magnesium found in certain carbonate minerals (eg.
dolomite, magnesite).

MgKCl: Potassium chlorde extractable magnesium measured following the T AA analysis, which includes soluble and exchangeable magnesium.
MgNAS: Net acld soluble magnesium. The calcium soluble In 4 M HCI that is not soluble in 1M KC1. (MgHClI -MgKCl. It can be used (in combination with
CaNAS) to provide an estimate of the soil carbonate content, but maybe an overestimate if magnesium is dissolved from non-carbonate or non-acid-neutraltsing

minerals,

Mgp: Peroxide magnesium. Magnesium measured following the TPA analysis, which includes soluble and exchangeable magnesium, as well as magnesium
{eg. from carbonates) dissolved as a result of acid produced due to oxidation of sulfides by peroxide.

Monosulfldes: Tha term given to the highly reactive iron sulfide minerais found In ASS that have the approximate formula 'FaS' and which ara soluble In”
hydrechtoric acid (as opposed to iron disulfldes such as pyrite that aren't appreciably soluble in hydrochloric acid).

Net Acidity: The result obtained when the values for’ various components of soil acidity and acid neutralising capacity are substituted into the Acid Base
Accounting equation. Calculated as: Net Acidity = Potential sulfidie Acidity + Existing Acidity -(Acid Neutratising Capacity/Fineness Factor)

Field pH. Fleid determination of pH in a ‘Soil:water paste.

pHFox: Field peroxide pH, Field determination of pH In a soil:water mixture following reaction with hydrogen peroxide.

pHKCt: Potassium chloride pH. pH in a 1:40 (W/V) suspension of soil In a solution of 1 M potassium chloride measured prior to TAA titration.
pHox: Peroxide oxidised pH. pH in a suspension of soil In a solution after hydrogen peroxide digestion in the SPOCAS method.

POCAS: An acronym standing for Peroxtde Oxidation Combined Acidity and Sulfate method (Method Code 21.). This method has been superseded by the
SPOCAS method.

POCASm: An acronym standing for the modified Peroxide Oxidation Combined Acidity and Sulfate method. This method has been superseded by the SPOCAS
method.

Potential (sulfidic) acidity: The latent acidity in ASS that will be reteasad if the sulfide minerals they contain (eg. pyrite) are fully oxidised, It can be estimated
by titration (ia. TSA) If no acid neutralising material is present, or calculated from SPOS or SCR results.

Retained Acidity: The ‘less available’ fraction of the existing acidlty (not measured by the T AA) that may be released slowly into the environment by hydrolysis

Bio-Track Pty Ltd