This paper presents a comparison between solid and resisitively loaded bowtie antennas in GPR applications for the purpose of finding buried landmines. The resistively-loaded antennas were first evaluated over dry sand in a laboratory-based experiment with a landmine surrogate. Further testing, comparing the performance of the loaded antennas to that of solid bowtie antennas, was performed over real soil, with a real landmine. Using the loaded bowtie antennas, the system got a response from the target in the indoor experiment but not in the outdoor experiment. The system did detect the buried landmine in the outdoor experiment when using the solid bowtie antennas. It is likely that the losses in the real soil were too high compared to the losses in dry sand for the system to be able to get a response using loaded antennas. The GPR system tested in this paper forms part of a dual-modality system for humanitarian demining applications.