Plot-and-berm agroecosystems in aeolian sand hinterlands around the Mediterranean basin: A case of regional agri-cultural connectivity? Dr. Joel Roskin Analytical Laboratory, The Artifacts Treatment, Conservation and Laboratories Dept., Israel Antiquities Authority, Israel

Overcoming the agricultural liabilities of loose sand such as scarce nutrients and low water retention remains a challenge for increasing global food production. Several historical societies have attempted agriculture in dunefields but these efforts are poorly recognized.

“Plot-and-berm” (P&B) agroecosystems consists of sophisticated agricultural utilization of a high-water table within loose, aeolian sand sheets. Sunken agricultural plots between 1-5 m high sand berms characterize P&B agroecosystems, situated in agricultural hinterlands (Taxel et al., 2018). Berms are often coated with anthropogenic refuse/fines to protect them from erosion. The agricultural plots, which lie slightly above the 1-4 m deep groundwater table, usually enable easy access to the water for crop roots and/or human water extraction. Refuse and organic material enrich the sandy soil in plots. The agroecosystems require significant resources for construction and maintenance, thus making their construction motivations intriguing.

The earliest recognized Mediterranean agroecosystems are Early Islamic (9th-early 12th centuries A.D.) ones along 3-4 coastal sand bodies of Israel that were abandoned by an unclear reason. Though Arabic literature reviews have not found descriptions of P&Bs, this effort may be an original type of mawāt (Arabic: “dead”) land reclamation, an important issue in Islamic economic history. Known from Early Islamic juristic documents, mawāt refers to unowned wastelands. Islamic jurists prescribed rules for mawāt vivification and acquisition, typically cultivated with irrigation systems, such as qanats.

Some of the P&B agroecosystems around the Mediterranean basin date back to the Middle Ages. Ghout with multi-layered organization of palms and fruit trees, and herbaceous crops (since the 15th century A.D.) in Saharan Algeria (Boualem & Rabah, 2011), masseira or gamela in the northern coast of Portugal, Navazo in southern Spain (since the 18th century A.D.) (Sánchez & Cuellar, 2016), and pre-modern mawasi in the southeastern Mediterranean coast are still active. One arid inland dunefield margin in northern Iran also contains hundreds of P&Bs. Ghout and mawasi agriculture practice use mechanized water drilling and modifications of the berms and soil surface level in response to fluctuating shallow groundwater levels.

The modern agroecosystems may be an inherited or revived manifestation of the hypothesized original Early Islamic effort in coastal Israel. Such biocultural knowledge may have been slowly transmitted across the (mainly Islamic) Mediterranean populations. The past P&B agroecosystems in arid and marginal zones are also a reminder that such environments may hold challenging potential for future agricultural exploitation.