ABSTRACT
Soil organic matter together with physical properties have been proposed as indicators of soil quality. The chapter presents a conceptual multidisciplinary soil environmental model to support the use of indicators in relation to agroecological functions. The basis for the conceptual model is supported with published information and data obtained from long-term crop rotation plots and soil quality benchmark monitoring sites in western and eastern Canada, respectively. Organic carbon dynamics represented an indicator to assess the impact of land use scenarios on carbon sequestration in Canada. Defining functional soil quality indicators helps identify horizontal links between the three facets of sustainable agriculture, and vertical links with policy makers and decision making authorities. Data show that oxygen-nitrogen sources, rate of nitrogen mineralization and the number of nitrifiers were components of the nitrogen cycle that responded to management. These three indicators can be used to evaluate nitrogen mineralization in sustainable agriculture.
