Israeli archeologists were successful in unlocking another secret of 1,500-year-old Byzantine agriculture in the Negev, using an innovative approach that led to surprising results.
The inhabitants of the Byzantine Negev used sheep manure to fertilize the green fields. However, with the transition to the Islamic period and the beginning of the collapse of the cities of the Negev, sheep droppings were no longer used for fertilization and were piled up in such large quantities that it was necessary to burn them.
A new study conducted at the University of Haifa together with researchers from the Israel Antiquities Authority (IAA) revealed additional, microscopic evidence that educates on the rise and decline of the Negev cities.
Halutza, Shivta, Nitzana, and Avdat were part of the Negev cities that flourished from the 4th century in the Byzantine period, relying on green and prosperous agriculture in the hot and dry Negev.
However, with the transition to the Islamic period in the 7th century, these settlements began to decline and were finally abandoned in the 10th century.
The decline of the Byzantine Negev settlements has preoccupied many researchers over the years. The various explanations refer to the political change caused by the transition from Byzantine rule to Islamic rule, or possibly climate change or economic changes that could explain the decline.
In recent years, Professor Guy Bar-Oz of the University of Haifa has been leading a series of studies that attempt to trace the processes and causes of the historical transition, with a new general approach at the center of the study – examining piles of garbage that were found at the outskirts of the settlements, rather than a traditional excavation within the settlements.
In previous studies, the researchers focused on macroscopic findings, those that can be seen by the naked eye, such as animal bones and plant remains that formed the economic base of the residents of the Negev.
The remains of the plant documented the extent of agricultural activity that reached its peak in the Byzantine period with the establishment of the wine production industry and its decline in the early Islamic period.
These and other findings testified to intensive agricultural activity in the Byzantine period versus limited agriculture in the Islamic period.
Now, for the first time, researchers have also decided to examine microscopic finds found in the dirt from which the garbage piles were composed.
The researchers were surprised to find that there was a significant difference in the materials from which the dirt in the garbage was composed between the Byzantine and Early Islamic periods.
In the Byzantine period, waste from construction materials such as clay and stones, and residues related to daily life such as ash from cooking and baking ovens, livestock bones, and pottery, were dumped. In the Islamic period, it was found that the soil consists mainly of farm animal manure that had lost its characteristic shape and now looks like dirt.
“Apparently, in the Byzantine period, manure was an important commodity used to fertilize agricultural fields, while in the early Islamic period this source of fertilizer was less and less used and therefore its excess had to be dumped in garbage dumps,” said Prof. Ruth Shahak-Gross, of the Department of Marine Civilizations and the School of Marine Sciences at the University of Haifa, one of the leaders in the research.
“We have a number of laboratory methods by which we can detect the remains of dung that have decayed over time, chiefly identifying microscopic pellets that form in the intestines of animals, especially sheep and goats, and because they are composed of inorganic material they are preserved at archeological sites,” Shachak-Gross explained.
In addition, investigators identified evidence of the burning of the garbage during the early Islamic-era using an infrared spectroscopy method.
“To the best of our knowledge, this is the first time we have identified the management of an ancient garbage site. To our understanding, such large surpluses of manure accumulated in the early Islamic period, due to declining agricultural activity in the fields and rising grazing activity, until the waste was needed to be treated, and this was done by burning it. We are witnessing a huge perceptual change regarding manure in both periods, from an expensive commodity as an important fertilizer source for agriculture to a useless nuisance thrown in the trash and burned there,” added Shahak-Gross.
“The picture emerging is that in both periods there is sustainable planning and management of resources, so while in the Byzantine period the population was based on economic adaptation, mainly agriculture combined with herds, in the early Islamic period the population underwent a process of adaptation to a herd-based economy, which is reflected in excess manure in the piles of garbage,” concluded Bar-Oz.