Located in the basalt desert of northeastern Jordan, Early Bronze Age (EBA) Jawa is regarded as one of the major settlements in the Middle East during the 4th millennium BCE. In addition to a sophisticated water storage system, the existence of three complex agricultural terrace systems based on runoff and floodwater irrigation in the close vicinity was recently revealed.This paper investigates the impact of these water management strategies on harvest yields and the scale of the ‘on-site’ crop production at Jawa by applying a crop simulation model (CropSyst). Simulations for the cultivation of winter barley, winter wheat and lentils were performed for the period from 1983 to 2014. To simulate the different runoff irrigation schemes, a curve-number-based rainfall-runoff model was applied. To estimate the number of people that could have been supplied by the local food production, simple calculations based on metabolic calorie requirements and agricultural and pastoral production rates were conducted.This study shows that the runoff farming systems of EBA Jawa are relatively effective under current rainfall conditions. Even during dryer seasons, the simulated crop yields are much higher under runoff irrigation/floodwater irrigation than under non-irrigated conditions. On average the crop yields increase by 1.5 to 6 times, depending on crop type and runoff irrigation level. Moreover, a marked decrease in crop failures could be observed. The total crop and animal production could have satisfied the nutritional requirements of about 500 to 1000 persons per year. Considering the estimated maximum population for EBA Jawa, ranging from 3400 to 5000 people (Helms, 1981), local production did not meet the basic needs of all inhabitants. This indicates that trade might have been an important branch of Jawa's economy in order to supplement food resources. Moreover, former population estimates for ancient Jawa might be overstated.

Selecting appropriate crops and applying deficit irrigation can help increase water productivity in water-limited regions such as the Mediterranean. The objective of this study was to develop water production functions of major cereal and legume crops under the same environmental and management conditions. Bread and durum wheat, faba bean, chickpea, and lentil were grown under full supplemental irrigation (FSI), two deficit irrigations levels of 2/3 of FSI (2/3SI) and 1/3 of FSI (1/3SI), and under rainfed conditions (no irrigation). In average, the actual evapotranspirations (ETs) under FSI were 549, 552, 365, 451 and 297 mm, for bread wheat, durum wheat, faba bean, chickpea and lentil, respectively. For the same crops, they were 463, 458, 330, 393 and 277 mm for the treatment 2/3SI and 357, 351, 265, 318 and 244 mm for the treatment 1/3SI, respectively. In the case of the rainfed treatment, ETs for the mentioned crops were 250, 251, 227, 237 and 215 mm, respectively. The experiment was conducted at the ICARDA experimental station at Tel Hadya, near Aleppo, Syria, over three growing seasons from 2007 to 2010.

Selecting appropriate crops and applying deficit irrigation can help increase water productivity in water-limited regions such as the Mediterranean. The objective of this study was to develop water production functions of major cereal and legume crops under the same environmental and management conditions. Bread and durum wheat, faba bean, chickpea, and lentil were grown under full supplemental irrigation (FSI), two deficit irrigations levels of 2/3 of FSI (2/3SI) and 1/3 of FSI (1/3SI), and under rainfed conditions (no irrigation). In average, the actual evapotranspirations (ETs) under FSI were 549, 552, 365, 451 and 297mm, for bread wheat, durum wheat, faba bean, chickpea and lentil, respectively. For the same crops, they were 463, 458, 330, 393 and 277mm for the treatment 2/3SI and 357, 351, 265, 318 and 244mm for the treatment 1/3SI, respectively. In the case of the rainfed treatment, ETs for the mentioned crops were 250, 251, 227, 237 and 215mm, respectively. The experiment was conducted at the ICARDA experimental station at Tel Hadya, near Aleppo, Syria, over three growing seasons from 2007 to 2010. Results showed that, in general, the treatment with 1/3 of FSI gave the highest rate of increase in grain yield and water productivity. The mean grain yield from rainfed, 1/3SI, 2/3SI, and FSI were 1.36, 3.82, 5.18, and 5.70t/ha for bread wheat; 1.24, 3.80, 5.10, and 5.75t/ha for durum wheat; 1.57, 2.35, 2.86, and 3.54t/ha for faba bean, 1.36, 2.63, 3.36, and 3.74t/ha for chickpea, and 0.64, 1.16, 1.42, and 1.58t/ha for lentil respectively. Grain yield reductions due to the application of 2/3SI were around 10, 5, 15.6, and 10.2% of FSI on average for wheat, chickpea, faba bean, and lentils, respectively. Deficit irrigation at 2/3SI increased water productivity compared to rainfed treatments, by 200, 223, 126, 148 and 190% for bread wheat, durum wheat, faba bean, chickpea, and lentils, respectively. However, differences in total water productivity of crops grown under full irrigation compared to deficit irrigation were not significant. Irrigation water productivity ranged from 25kgha⁻¹mm⁻¹ in wheat with 1/3SI to 10kgha⁻¹mm⁻¹ for legumes under the FSI treatment. Unlike legumes, maximizing wheat grain yield caused a decline in water productivity.

Selecting appropriate crops and applying deficit irrigation can help increase water productivity in waterlimited regions such as the Mediterranean. The objective of this study was to develop water production functions of major cereal and legume crops under the same environmental and management conditions. Bread and durum wheat, faba bean, chickpea, and lentil were grown under full supplemental irrigation (FSI), two deficit irrigations levels of 2/3 of FSI (2/3SI) and 1/3 of FSI (1/3SI), and under rainfed conditions (no irrigation). In average, the actual evapotranspirations (ETs) under FSI were 549, 552, 365, 451 and 297 mm, for bread wheat, durum wheat, faba bean, chickpea and lentil, respectively. For the same crops, they were 463, 458, 330, 393 and 277 mm for the treatment 2/3SI and 357, 351, 265, 318 and 244 mm for the treatment 1/3SI, respectively. In the case of the rainfed treatment, ETs for the mentioned crops were 250, 251, 227, 237 and 215 mm, respectively. The experiment was conducted at the ICARDA experimental station at Tel Hadya, near Aleppo, Syria, over three growing seasons from 2007 to 2010. Results showed that, in general, the treatment with 1/3 of FSI gave the highest rate of increase in grain yield and water productivity. The mean grain yield from rainfed, 1/3SI, 2/3SI, and FSI were 1.36, 3.82, 5.18, and 5.70 t/ha for bread wheat; 1.24, 3.80, 5.10, and 5.75 t/ha for durum wheat; 1.57, 2.35, 2.86, and 3.54 t/ha for faba bean, 1.36, 2.63, 3.36, and 3.74 t/ha for chickpea, and 0.64, 1.16, 1.42, and 1.58 t/ha for lentil respectively. Grain yield reductions due to the application of 2/3SI were around 10, 5, 15.6, and 10.2% of FSI on average for wheat, chickpea, faba bean, and lentils, respectively. Deficit irrigation at 2/3SI increased water productivity compared to rainfed treatments, by 200, 223, 126, 148 and 190% for bread wheat, durum wheat, faba bean, chickpea, and lentils, respectively. However, differences in total water productivity of crops grown under full irrigation compared to deficit irrigation were not significant. Irrigation water productivity ranged from 25 kg ha−1mm−1 in wheat with 1/3SI to 10 kg ha−1mm−1 for legumes under the FSI treatment. Unlike legumes, maximizing wheat grain yield caused a decline in water productivity.

A compromise programming based model has been developed for maximizing food production with minimum allocation of available water at watershed scale after meeting human, livestock and environmental needs under different scenarios. Agricultural water allocation in conjunction with available land resources under a set of constraints has been examined. The formulated model has the potential to analyze the implications of water availability on agricultural water allocation plans, and consequently food production. A case study in Indian Himalayan region, where despite abundant availability of water, rainfed agriculture is mostly practiced by majority of farmers with a primary objective of self-sufficiency in food production, well demonstrates the applicability of the developed model. Three distinct scenarios affecting water availability were considered. Analysis of imposition of fixed mandatory outflows of 20 to 70 % (as per water source) for satisfying environmental needs with present production mix revealed water scarcity within the study watershed ranging from 4 to 66 % across various quarters of an year, which necessitates optimum utilization of rainfed fallow land by allocating it to high value crops ginger and lentil (6 to 32 times more than existing allocation) on one hand, and drastic reduction (76 to 100 %) of area under all irrigated crops (except onion with 4–6 times increase) on the other, to achieve the conflicting objectives. The compromise plans also suggested increase (by 14 % in environmental watershed scenario) or decrease (by 29 % in degraded watershed scenario) in size of livestock population as per scenario based water availability. Overall, the compromise plans were successful in achieving a high percentage (>93 %) of ideal values of the objective functions, which were 155 to 170 % of existing food production and 71 to 85 % of existing water utilization across the scenarios. The proposed optimization model has the potential for application in identical agro-climatic settings to enhance food production in an environmental friendly manner.