Impact of farmland fragmentation on rainfed crop allocation in Mediterranean landscapes: A case study of the Lebna watershed in Cap Bon, Tunisia

•We quantified the impact of crop sequences and neighboring crops on crop allocation.•We addressed this issue within a highly fragmented Mediterranean rainfed landscape.•For isolated fields, both crop sequences and neighboring crops drive crop allocation.•For non-isolated fields, crop allocation is mainly driven by crop sequences.•Farmers rely on collective rules of crop allocation to address common constraints.