There aren’t any requirements to have specific adjustments and it’s quite typical to have the information you described in a land only appraisal. Unless there are some type of improvements to the land (buildings, irrigation system, roads, etc) there isn’t a good way to specify adjustments based on just the land. The note that one was weighted more heavily probably indicates that the appraiser deemed this property most similar to the subject property. The appraiser may an have included an addendum to the appraisal that gives more information.