A thousand years ago, farmers in the inhospitable Negev developed a unique method of sustainably farming the terrible land, which that would be adopted throughout the region. The remnants of their agricultural innovation dots the sand dunes around Yavneh.
An oddity in these dunes had been pits roughly two meters in depth and measuring 10 by 10 meters. In summer, they fill with weeds. But in winter, a little water accumulates in them.
The first to identify this as method, rather than geological weirdness, was the archaeologist Sefi Porat, who excavated in Caesarea in the 1970s and found sunken plots of formerly cultivated land among the dunes. Now the archaeological survey led by Prof. Moshe Fischer of Tel Aviv University, and the archaeologist who actually found the pits, Dr. Itamar Taxel of the Israel Antiquities Authority, noticed the similarity in Yavneh.
Pottery bits found in the pits date to the early Islamic period, which runs from the 10th to the 12th century C.E.
“At first, we thought these were parking spots for caravans, or the sites of small communities,” Taxel said. But when Dr. Yoel Raskin, a geomorphologist from the University of Haifa, examined the pits, he suggested that they were like the system discovered in the earlier study of the Caesarea dunes. Additional excavations confirmed this hypothesis.
The return on investment in this system is not terrific. The farmer had to dig up a large amount of sand and then plant trees whose roots would be able to draw water from the groundwater lying 1.5 to two meters below the surface.
Yet they did it, and the discovery of the pits and what they were explain why nobody found wells or irrigation systems in this desert farming sites. “This was a major investment, but apparently it paid," says Taxel.
Given the enormous investment, though, the archaeologists suspect that it was run by a regional administration, not individual farmers. Specifically, the researchers believe the pit farms were associated a military citadel located in Yavne-Yam at the time. “The citadel had an interest in having a friendly civilian population around it, and therefore, would promote this,” Taxel suggests.
The Crusader effect
Just how did the pits survive a thousand years? They were lined with a mixture of earth and pottery fragments that somwhat protected the pits from the elements and helped trap the rainwater, says Raskin. Large sand embankments could also be discerned around the pits.
The researchers dug up the fertile layer and dated it with optically stimulated luminescence, a method that enables archaeologists to determine when land was tilled by determining when the quartz crystals in it were last exposed to the sun. This method, like the potsherds, dated the pits to somewhere in the 10th to 12th centuries. The dunes are believed to have built up higher after this Medieval period.
This method of agriculture was only used for about a century. It might have lasted longer but ceased when the Crusaders conquered the area in the 12th century.
Before the Crusaders arrived, however, it seems that as Islam spread westward, it brought this method to other places. Similar but later sites dating from the 15th to 17th centuries have been found in Algeria, Portugal and Spain. In Algeria, some 9,000 plots of land are farmed with a similar system to this day.
In the 19th century, with the arrival of mechanization, a similar system known as mawasi was employed in the Land of Israel, based on digging up large tracts of land along the coast using hvy machinery, and growing crops irrigated by groundwater. This method was used so extensively in the southern Gaza Strip that the area is now called Al-Mawasi. And under the British Mandate, Arab farmers planted small orchards in natural depressions between the dunes that were close enough to the groundwater for the trees to survive.
Unrelated studies had found other secrets of richly farming the desert. One was the cultivation of midget pigeons relieving themselves. That is why early Christians in the region plunked their dovecotes in the middle of their fields. The prosperity of the desert farming community 1,500 years ago was deduced based on the otherwise inexplicable prevalence of a fussy rodent, the jird, which does not thrive unless grain does too.