Microwave heating of soil offers the potential to enhance infrared signatures of buried objects such as landmines. In uniform soil, with no vegetation and a flat surface, images can be obtained showing the shape of the objects, to aid in their identification. Combined with other subsurface imaging modalities, this promises a reduced false alarm rate, leading to more effective demining operations. However, in the presence of rough ground, non-uniform soil, vegetation, and solar heating, the signatures become much more complicated. In this work, we examine some of these issues, based on outdoor experiments and a two-dimensional model.