The aim of the approach proposed in this paper is to determine a potential crop extent prior to the crop season, by determining regions that might change in time vs. those that surely do not change. We use multi-annual PALSAR-1 data since in dry conditions, L-band HH/HV data have a potential of distinguishing between bare soil and other classes. In addition, a more accurate map can be reached with multitemporal data than using a single date. We work on HH and HV data sets separately and analyze the two outputs using ground-truth information. In a final phase, we combine these two outputs and compare the result with the ground-truth too, to test the usefulness of fusing the HH/HV information. This approach is the first step in our three-step procedure for estimation of cultivated area in small plot agriculture in Malawi. Validation results show that the proposed approach is promising.