A survey of the clay fraction at the surface of 86 loam and silt loam agricultural soils from the Central United States was undertaken to observe the possible influences of climate and parent material (dominantly phyllosilicates in this study) on the clay mineralogy of the upper portions of the soils, for the most part in Mollisol–Alfisol order soils.

Decomposed X-ray diffraction spectra show that the most abundant clay minerals are two disordered illite-smectite (I-S) minerals, one with ∼50% smectite layers and another, less abundant, disordered I-S phase with 20% smectite. These minerals usually co-exist in the same samples. The charge site in both of these I-S minerals is both beidellitic and montmorillonitic in the expanding layers. A relatively large proportion of these smectite layers (up to 20%) are of high charge.

There seems to be a convergence in mineralogy towards mixed-layer phases formed under a range of mid-Continent climates from a range of phyllosilicate parent materials.

Rural, natural and peri-urban areas seem nowadays to become the object of conflicts and tensions because of their multi-functional nature. If these conflicts issue from opposing views about the use of land, they are also determined by the spatial parameters that characterize the pieces of land affected by the projects of land-use transformation, and by the antagonistic relationship between two or several units of action (farmers and local planners, for example). Therefore, there is a need for a new management of rural (and peri-urban) areas, and this is the role of territorial governance, which is the engine of local development, and the tool for better local compromises, involving periods of opposition and streams of negotiation. Territorial governance has to take into account not only negotiations but conflict relations as well and to include both interaction schemes into its framework. Our study assesses the role played by conflicts in land use within a peri-urban context, based on studies on the Greater Paris region, and a case study on the use of agricultural soils on the urban fringe.