Limekiln services soil enrichment and water retention of an Early Islamic Plot-and-Berm groundwater-harvesting agroecosystem in coastal dunes near Caesarea, Israel

Limekilns, common throughout the southern Levant in carbonate rock highlands, were rare in aeolian sand terrains. This study presents for the first time a limekiln within an archaeological landscape of an Early Islamic groundwater harvesting Plot-and-Berm agroecosystem, in an anthropogenically modified Mediterranean coastal dunefield near the ancient town of Caesarea. The agroecosystem consists of a checkerboard landscape pattern of human-made rectangular depressions used as agricultural plots possessing a distinct dark gray anthrosol. The anthrosols made of sand mixed with domestic refuse transported from Caesarea are hypothesized to retain physical agricultural utilities. The plots are confined by anthropogenically designed, sand-based berms, coated by anthrosediments. Applying archaeological, minerological (FTIR), microarchaeological (thin section analysis), portable OSL reconnaissance profiling, and OSL dating, coupled with similar data from nearby anthrosols and anthrosediments of the agroecosystem, we demonstrate that the limekiln produced pyrogenic lime. The lime additives, in combination with the refuse, enrichened and stabilized the aeolian sand substrate and probably improved its water retention capacity. These actions demonstrate an additional technological innovation regarding water harvesting in “dead” lands that, in turn, supported for a defined timespan extensive agricultural practice whose crop types/species remain a mystery. The limekiln possibly functioned for a couple hundred years, contemporary and imbricated with the P&B agroecosystem. It is the first evidence of such an endeavor to improve sandy soil properties for a novel and ancient agricultural practice.