ISO 14388-2:20 14规定了一套用于测定酸性硫酸盐土壤净酸度的方法。ISO 14388-2:20 14规定了一种在酸性氯化铬消解后，通过碘量滴定以硫化锌形式捕获的蒸馏硫化氢来测量铬可还原硫(SCR)的方法。该方法测定酸性硫酸盐土壤中的无机硫化物（如黄铁矿、白铁矿、灰铁矿、麦基纳威铁矿）和元素硫，不受有机硫和氧化形式硫（如硫酸盐）的干扰。 在土壤的单独测试部分上，测定1mol/l KCl土壤悬浮液（pHKCl）中的pH。当pHKCl<6.5时，然后测定可滴定的实际酸度(TAA)。随后，还可以测定氯化钾可萃取硫(SKCl)、钙(CaKCl)和镁(MgKCl)。如果在土壤中发现黄钾铁矾（或pHKCl<4,5），则通过盐酸可提取硫（SHCl）和氯化钾可提取硫之间的差异来确定净酸溶硫（SNAS）。在pHKCl<6.5的样品上，酸中和能力通过通过燃烧炉测量无机碳(CIN)或ANCBT(通过酸消化后剩余酸的反滴定测量的ANC)来确定。

ISO 14388-2:2014 specifies a suite of methods used to determine the net acidity in acid sulfate soils. ISO 14388-2:2014 specifies a method for measuring chromium reducible sulfur (S_CR) by iodimetric titration of distilled hydrogen sulfide trapped as zinc sulfide, following acidic chromous chloride digestion. This method determines inorganic sulfides (e.g. pyrite, marcasite, greigite, mackinawite) and elemental sulfur in acid sulfate soil without interferences from organic sulfur and oxidized forms of sulfur such as sulfate. On a separate test portion of soil, the pH in a 1 mol/l KCl soil suspension (pH_KCl) is determined. When pH_KCl is < 6,5, titratable actual acidity (TAA) is then determined. Subsequently, potassium chloride extractable sulfur (S_KCl), calcium (Ca_KCl), and magnesium (Mg_KCl) can also be determined. Where jarosite is identified in the soil (or where pH_KCl is < 4,5), net acid-soluble sulfur (S_NAS) is determined by the difference between hydrochloric acid extractable sulfur (S_HCl) and potassium chloride extractable sulfur. On samples where pH_KCl is < 6,5, acid neutralizing capacity is determined by measuring either inorganic carbon (C_IN) by combustion furnace, or ANC_BT (ANC measured by back-titration of acid remaining following an acid digest).