ISO INTERNATIONAL STANDARD 14388-2 First edition 2014-08-01 Soil quality - Acid-base accounting procedure for acid sulfate soils Part 2: Chromium reducible sulfur (CRS) methodology Qualité de I'eau - Meéthode de comptage acide-base pour les sols sulfatés acides- Partie 2: Meéthode de sulfato réduction au chrome Reference number IS0 14388-2:2014(E) LSO @ IS0 2014 I without license from IHS Not for Resale IS0 14388-2:2014(E) COPYRIGHTPROTECTEDDOCUMENT ISO2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56:CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland @ IS0 2014 - All rights reserved No reproductic networking permited without license from IHS Not for Resale IS0 14388-2:2014(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references ...1. 3 Terms and definitions ..2 4 Principle .2 4.1 Potential sulfidic acidity. . 2 4.2 Actual acidity and retained acidity .2 4.3 Acid neutralizing capacity. .2 5 Reagents foranalysis of chromium reducible sulfur ..2 6 Apparatus ..4 7 Procedure for determining chromium reducible sulfur ..5 8 Calculation of ScR ..7 9 Reagents for determination of pHkci and TAA ..8 10 Procedure for determination of pHkc and TAA 10.1 Preparation of the suspension. .9 10.2 Measurement of pHkcl 10.3 Measurement of TAA ..10 11 Calculation of TAA .11 12 Procedure for determination of sulfur (Skcl), calcium (Cakcl), and magnesium (Mgkcl) extractable with 1 mol/l potassium chloride .11 13 Calculation of Skc, Cakcl, and Mgkcl .12 14 Reagents for determination of sulfur (SHc), calcium (CaHcI), and magnesium (MgHci) extractable with hydrochloric acid. .12 15 Procedure for determination of sulfur (SHcI), calcium (CaHcl), and magnesium (MgHcl) extractablewithhydrochloricacid 12 16 Calculation of net acid-soluble sulfur (SNAs), calcium (CaNAs), and magnesium (MgNAs)...13 17 Reagents for determining acid neutralizing capacity by back-titration (ANCBT) ..13 18 Procedure for determining acid neutralizing capacity by back-titration (ANCBT) ..14 18.1 Hotplate digestion with hydrochloric acid solution ..14 18.2 Titration of unreacted acid in digested soil suspension ..14 19 Alternatives for determination of acid neutralizing capacity ..15 20 Precision .15 21 Test report ..16 Bibliography. ..18 iii t license from IHS Not for Resale