Data and methods to assess soil organic matter at regional scales

Abstract : Spatial studies on soil organic matter assessment have recently moved from plot and field scale approaches to larger scales, to tackle new issues linked to soil carbon sequestration and landscape planning. Our objective is to present an overview of existing data and methodological approaches to modelling SOM at landscape and regional scales. We briefly review the methods developed to model SOM at the plot scale. Then we consider existing data and modelling approaches at larger spatial scales and discuss several emerging issues at those scales such as representation of soil and farming practices variability, landscape features and, validation processes. Finally, we discuss the interest and limits of the current modelling approaches and outline a framework for modelling SOM and related functions at the landscape scale.