Soil organic carbon 2008-07-17T00:15:14Z 2008-09-05T01:47:44Z Soil organic carbon Indicator protocols for soil condition National Land and Water Resources Audit National Land and Water Resources Audit <p>Soil organic matter is a key soil component and plays a critical role in a range of physical, chemical and biological soils processes (Baldock 2007).<br /> Soil organic matter:</p> <ul> <li>provides energy for biological processes (Fontaine et al. 2003) and nutrients N, P, S</li> <li>improves the structural stability, influences water retention properties and alters thermal properties</li> <li>contributes to cation exchange capacity, enhances pH buffering and complexes cations.</li> </ul> <p>Soil organic carbon is relatively easy to measure. Its concentration is a useful indicator of soil condition and the quantity of soil organic carbon is emerging as a key factor in greenhouse gas mitigation. For these reasons soil organic carbon is a &lsquo;headline&rsquo; soil condition indicator both nationally and internationally.</p> <p>The recommended measures of soil organic carbon are:</p> <ul> <li>baseline SOC expressed as a percentage and as density (tonnes per hectare)</li> <li>change in SOC over time.</li> </ul> PN21222 PN21222