Presentation on theme: "Water Use Efficiency and Water Productivity in Jordan M. Duqqah* S. Mazahreh** M. Shatanawi* A. Fardous** * Faculty of Agriculture, University of Jordan."— Presentation transcript:
Water Use Efficiency and Water Productivity in Jordan M. Duqqah* S. Mazahreh** M. Shatanawi* A. Fardous** * Faculty of Agriculture, University of Jordan ** NCART, Ministry of Agriculture
Introduction Jordan is considered to be one of the 10 poorest countries worldwide in water resources, and has a population growth rate of about 2.9% ( ), the 9th highest in the world. The available renewable water resources are dropping drastically to an annual per capita share of 160 m3 in recent years, compared to 3600 m3/cap/a in 1946.
Introduction Factors prompting such a decrease include, aside from the most prominent one of steep population growth, sudden influx of refugees due to political instability in the region. Currently irrigated agriculture is the largest consumer constituting around 64% of the overall uses compared to only 36 % for municipal, industrial and tourism (MIT) purposes
Irrigation Sector Irrigation in Jordan occurs mainly in three distinct areas: 1.The Jordan Rift Valley. 2.The North-eastern Desert and Azraq region. 3.The Southern Desert in the Disi and Mudawwara areas.
Irrigation Sector The Jordan Valley Authority (JVA) supplies irrigation water in the Jordan Rift Valley (JRV), using surface water from Yarmouk River and the side wadis, in addition to treated wastewater. Groundwater is used to a lesser extent in the Valley mostly by farmers in the Southern part of the Valley
Irrigation Sector In the uplands, irrigation water is pumped from licensed or unlicensed private wells, tapping both renewable and non- renewable groundwater, and to a lesser extent form surface water.
Historical Water Consumption in Irrigation Sector The irrigation share of the total water uses demonstrates significant decrease during the period (78% in 1985 to 64% in the year 2002). In absolute figures irrigation water use has also been reduced from its peak in 1993 (726 MCM/a) to 511 MCM in the year 2002.
Historical Water Consumption in Irrigation Sector Factors contributing to such decrease may be: 1.Restrictions on well drilling. 2.Equipping private wells with water meters. 3.Reduction in irrigated areas due to water shortages ensuing from the persistent drought throughout 1998 – 2002.
Historical Water Consumption in Irrigation Sector The use of surface water for irrigation in Jordan has declined in both absolute and relative terms from 249 MCM (42%) of total irrigation use in 1996, to 157 MCM (31%) in Groundwater use decreased from 290 MCM in 1996 to 216 MCM in 2002, with a steady relative portion of 48% of total uses.
Historical Water Consumption in Irrigation Sector The amount of treated wastewater used in irrigation rose from 59 MCM (10%) in 1996 to 70 MCM in 2002 (16%) nationwide. Due to the progressive replacement of fresh water with treated wastewater originating at the highlands, mostly from Amman-Zarqa urban area, the use of treated wastewater for irrigation in the JRV has been increasing steadily and is currently estimated at some 60 MCM; about 84% of the total effluent reuse nationwide.
Water Efficiency and Productivity Water Efficiency One of the most extensively used terms to evaluate the performance of an irrigation system is “water efficiency”. Efficiency is generally understood to be a measure of the output obtainable from a given input.
Water Efficiency In irrigation, the delivery of water from water sources to field crops depends on the efficiency in three main levels of an irrigation system: a)conveyance, b)distribution, and c)field (on farm) application.
Conveyance Efficiency Conveyance is the movement of water from its sources (reservoirs, river diversions, wells or pumping stations) through main and secondary canals to the tertiary off take of a distribution system.
Distribution Efficiency Distribution is the movement of water from tertiary and distribution canals, channels or pipes to individual field inlets.
Network Efficiency Often, the combined efficiency of a conveyance and distribution system is described as irrigation network efficiency. It is defined as the water delivered to farm field inlets divided by the water diverted from the prime source.
Field application Field application is the movement of water from field inlets to crops. The field (or on- farm) efficiency is defined as net volume needed to maintain the soil moisture, which is equal to the amount consumptively needed for evapo-transpiration.
Overall or Project Efficiency Another concept widely used in irrigation is the overall or project efficiency. It is the ratio between the quantity of water consumptively used by crops and the total water diverted from the sources to a project area. It encompasses seepage and evaporation losses incurred in physically conveying water to crops, as well as losses due to deep percolation through the root zone to groundwater and field runoff.
Irrigation Sector Efficiency Finally, irrigation sector efficiency is defined as the amount of water actually consumed by the sector divided by the amount of water made available for the sector of a country.
Table 1: Irrigation Water Use Efficiencies at Various Levels Level(%)Specification Network Level75Open canals with manual control, on-farm sprinkler/drip storage & On-farm Level70Open canals with manual control, on-farm storage & sprinkler/drip Overall Level53Open canals with manual control, on-farm storage & sprinkler/drip Sector Level4238 % for surface distribution and 70% for direct pipe distribution Source: Le Moigne, G., S. Barghouti, M. Xie, et. al. 1992a
Water Productivity Historically, farm productivity was measured in yield per hectare, since land was the constraining resource. But as the twenty-first century begins, policymakers are beginning to look at water as the limiting factor for food production. The common measure that is emerging to measure water productivity is kilograms of grain produced per ton of water.
Water Productivity Oweis, et al. (1999) define water productivity as the ratio of the physical yield of a crop and the amount of water consumed, including both rainfall and supplemental irrigation. Yield is expressed as a mass (kg or ton), and the amount of water as a volume (m3).
Water Productivity The efficiency concept provides little information on the amount of food that can be produced with an amount of available water. In this respect, water productivity, defined as the amount of food produced per unit volume of water used is more useful. Because the water used may have various components (evaporation, transpiration, gross inflow, net inflow, etc.), it is important to specify which components are included when calculating water productivity
Case Study: GHORS, JORDAN The sample farms in the Ghors area of Jordan comprised 70 producers, distributed among 23 villages. The villages are clustered into two districts (North Ghors and Deir Alla Ghors) with most of the producers located in the North Ghors district (63 per cent). The rest of the producers, 37 per cent are located in the Deir Alla Ghors.
Table 2: Descriptive Statistics for Sample Farms in the GHORS Area Crops Citrus Cauliflower CucumberPepperSquash Potatoes TomatoesTotal farm Item Number of farms Area (ha) Mean SD ¥ N.A b/ N.A b/ Crop yield (kg/ha) Mean SD ¥ Water applied (m3) Mean SD ¥ Irrigation(m 3 /ha) Experience in irrigation (year) Rain fall (mm) mean SD ¥ Total water use (irrigation-rainfall)m 3 /ha c/ N.A b/ c/ N.A b/ c/ c/ c/ Water productivity(kg/m 3 ) c/
Case Study: GHORS, JORDAN The annual rainfall for the study area during the 2000/2001 season was mm. The crop yield was the highest, for tomatoes 60.3 ton/ha, followed by cucumber, 52.2 ton/ha. The crop yields of other crops are presented in table 2.
Case Study: GHORS, JORDAN Water productivity, defined in technical terms as kg of output per m3 of water, is the highest for tomatoes and lettuce (8.48 kg/ m3 and 7.22 kg/ m3, respectively). If the amount of rainfall is excluded, the crop water productivity will change considerably. The results indicate that water yields more output in the production of tomatoes, potatoes, lettuce and beans.
Case Study: GHORS, JORDAN To better represent farm economic conditions, output prices need to be taken into account as well. Thus, water productivity will be redefined in monetary terms as Jordanian Dinars (JD) of output per m3 of water (table 3).
Table 3: Water Productivity (JD/M 3 ) Water productivity(JD/m 3 )Water productivity (kg/m3) Without rainfallWith rainfallWithout rainfallWith rainfallPrice(JD/Kg)Crop Tomatoes Potatoes Squash Cucumber Citrus Wheat Eggplant Lettuce Beans Broad beans
Case Study: GHORS, JORDAN Under this definition, the water productivity is the highest for lettuce (1.877 JD/ m3), followed by beans (1.806 JD/ m3), then broad beans (1.01 JD/ m3). These results show that changing the definition of water productivity from technical to monetary terms has important implications on the ranking of crops with respect to water productivity. Although tomatoes come in the first order under the concept of technical efficiency, they come in the fourth place when monetary concept is used.
Case Study: GHORS, JORDAN Results of the survey clearly demonstrate that water allocation among competing crops is mainly determined by the area planted in each crop. Economic conditions, according to sample farms, do not affect water allocation and application among crops. Further, the amount of water applied to each crop is mainly determined by general rules and farmers’ experience.
Case Study: GHORS, JORDAN Under these circumstances the main problem facing farmers in the Ghors area is allocation of water resource among competing crops, and this can be easily done by using the behavioural model. Survey data indicate that the amount of irrigation water applied for squash, broad beans and cabbage is fixed for all farmers producing these crops.
Case Study: GHORS, JORDAN Results of farm survey reveal that farmers behave as if their production functions follow constant returns to scale. Therefore, farmers adapt recommended input- output ratios (norms) developed by extension system. Table 4 presents estimated and actual water use, as an average of sample farms, derived from the behavioural model.
Table 4: Estimated and Actual Water Use in GHORS Area / JORDAN WUE b/ WUE a/ Required water(m 3 ) Actual water used(m 3 ) Yield (ton/ha)Irrigated area Crop Tomatoes Potatoes N.A c/ Squash N.A0.65Peppers Cucumber N.A0.39Cauliflower Citrus N.A0.37Melons Wheat Eggplant Lettuce Beans N.A c/ Broad beans N.A c/ Cabbage Onions
Case Study: GHORS, JORDAN In fact potatoes, peppers, lettuce and onions require more water than actual water applied to produce the achieved yield levels by sample farms. Above-average yields and a very efficient use of irrigation can explain these estimates of very high ratios of WUE for all crops.
Case Study: GHORS, JORDAN If the amount of rainfall is taken into consideration in the calculation of WUE, the efficiency of irrigation water will drop sharply, implying that producers over- irrigate their crops. The percentage of over-irrigation ranged from a minimum of 23 per cent in the production of citrus crops to a maximum of 70 per cent in the production of wheat.
Case Study: GHORS, JORDAN If Citrus and eggplant productions are relatively more efficient with a WUE of 0.77 per cent and 0.66 per cent, respectively. Farmers of potatoes, cauliflower, melons, wheat, lettuce, beans and onions are less efficient as they exceed water requirements by more than 50 per cent. Producers of tomatoes, peppers and cucumbers achieved medium level of water use efficiency as they exceed water requirements by less than 50 per cent.
Case Study: GHORS, JORDAN The low ratios of water use efficiency in potatoes, cauliflower, melons, wheat, lettuce, beans and onion production suggest that a wide technology gap exists between the recommended irrigation in the study area. This result has important policy implications, since Jordan is classified as a water-scarce country. Therefore, improving water use efficiency for these crops can contribute to the overall water use efficiency for the agricultural sector.
Case Study: GHORS, JORDAN Rainfall in Jordan is often not distributed adequately and timely in line with plant needs. Large gaps between rainfall periods negatively affect the plant. Therefore farmers should always irrigate when necessary in line with the plant requirements due to the irregularities of rainfall. WUE estimations then can be misleading when rainfall is considered.