Using Designed Terraces Systems for Sustainable Management of Degraded Arid Loess Cultivated Lands. Attir Farm, Northern Negev, a Case Study.

Loamy soils cover wide part of the arid lands. These soils characterized by high content of fine particles which enable them to absorb and conserve high amounts of nutrients and organic matter which is crucial for successive and continuant agriculture use, from the other side, the high fine particles amount made these soils highly sensitive to physical interferences as tillage and other soil processing practices used for the cultivation. In field, these areas are exposed to massive soil erosion and incision phenomena which can be spread and enlarged till massive damage to their continuant agriculture use. An example for such areas is the cultivated lands in the northern Negev that suffer from massive erosion and cover by dense gullies nets. In order to examine potential solution, which will halt the incision and enable sustainable use, chains of terraces were constructed on the streambeds of wadi Attir farmland cultivated areas at 2011. The terraces and the limans between them (The term 'Liman' refers to the area between two adjacent terraces) were differentially designed and managed and their soil fertility properties were periodically determined. Our finding indicate that planted limans (with native trees), two years after their construction and conservation, increased the soil productivity up to 6-13 fold with compare to their surrounding cultivated areas; at the fourth year, an enrichment of 75% was observed up to 4m from their edges and at the fifth year these impacts were observed without additive trees' irrigation. Based on our findings, three rehabilitation models were built for cultivated areas with constructed limans including tilled croplands, rangelands and groves even ones in severe degraded state. We assure that these models together with the acquired practical experience will enable sustainable agriculture use for similar areas all over the globe.