CANADA

This report is presented as received by IDRC from project recipient(s). It has not been subjected to peer review or other review processes. This work is used with the permission of Elias Salameh. © 2000, Elias Salameh.

INTERNATIONAL DEVELOPMENT RESEARCH CENTER (IDRC) CENTRE DE RECHERCHES POUR LE DÉVELOPPEMENT INTERNATIONAL (CRDI)

CANADA

PROJECT TITLE Analysis and Review of the Prospects of Implementing a Differential Irrigation Water Pricing/Tariff System in the Jordan Rift Valley CENTRE FILE WDMRN 060025

TECHNICAL REPORT

PREPARED BY: Elias Salameh Hydrology Department University of Jordan

Raed Daoud EnviroConsult Office Amman, Jordan June 2000

1.

EXECUTIVE SUMMARY

Different water supplies with different qualities are used for irrigation in the Jordan Valley. Historically, fresh water resources were developed from the Yarmouk River and side wadis. Expansion of agriculture and reallocation of fresh water resources to high water uses, i.e. municipal and industrial, has pushed the system to adapt to water shortages by using treated wastewater and other marginal water sources in the valley. Irrigation water supplies in the Valley vary based on various quality parameters: physical, chemical, and biological. These quality parameters have varying impacts on agriculture and production in the valley. To price water based on quality differences only, one would assume that other farming factors are neutralized. However, agriculture productivity is a combined function of several faming factors: soils, on-farm management, climate conditions, and others. For example, soil quality might prevail and be the determining factor, even if the chemistry of irrigation water is the same. The third factor, which affects crop productivity, is the climate that imparts different rates of rainfall and different evaporation potentials, for the different parts of the Jordan Valley, which by the same irrigation water chemistry and soil properties result in different productivities. To reach an equitable and fair precondition for farmers the effects of the natural factors of water, soil and climate on productivity have to be reflected in pricing the different water sources. The different parameters included in the elements of water chemistry, soil characteristics and climate in the Jordan Valley area such as the salinity of water, its content of calcium, sodium, magnesium, chloride… etc., soil salt content, soil texture, drainability etc, and the average amount of annual rainfall and the potential evaporation rates were considered as the basis for crop productivity and hence for pricing water. In the context of water chemistry, water in the Jordan Valley was categorized for water pricing policies as follows: In addition to the general properties of water soil and climate mentioned above, some other specific parameters have to be taken into water pricing policies, of these; microbiology, nitrate and phosphate content, trace elements, suspended solids, boron, soil-SAR, are of particular interest. For the pricing policy, and in order to reach equity among farmers the present study concluded that the following equation should be worked out in terms of defining the magnitudes of the general factors “a” to “g” through a field study in order to set fair water prices. Water Price = +

a Salinity

+

b SAR

+

c * nutrient content + d * rainfall

e + f + g * amount of water use Soil Salinity Soil - SAR planted area

i

The study concludes also that monitoring programs for the natural factors in the Jordan Valley area should be initiated and implemented. In addition, the ability and willingness of farmers to pay for irrigation water have to be studied in detail taking the socio-economic aspects of farmers in due consideration. Given the nature of irrigation tariff structures based on water quality variations, the following policy-related issues need to be revisited continuously: •

Water quality parameters that should be used for tariff setting. Salinity, pathogens, and chloride are recommended for initial consideration in irrigation tariff setting. However, due to potential future changes in water resources and their qualities additional parameters might need to be considered in tariff setting;

•

Monitoring programs needed in the Jordan Valley. Monitoring of water, soils, and plants in the Jordan Valley are essential for tariff setting. The parameters that should be monitored and monitoring frequency have to be determined based on clear objectives for tariff setting purposes;

•

Other policy issues that affect farming, water quality, and tariffs. Given the increasing contribution of treated wastewater into the JVA irrigation water budgets and the reallocation of fresh water to urban uses, the viability of wastewater mixing polices versus isolation for different farming practices and crops should be investigated. Other government policies related to marketing, tax protection of certain crops and subsidies among urban and agriculture uses among other factors should also be assessed; and

•

Willingness and ability of farmers to pay for irrigation water. The Jordan Valley farms structure contains different sized farms, technologies, cropping patterns, water qualities, marketing processes, etc. In lieu of these factors, the ability and willingness of various farmers in the Jordan Valley to pay for irrigation water should be studied.

ii

TECHNICAL REPORT Analysis and Review of the Prospects of Implementing a Differential Irrigation Water Pricing/Tariff System in the Jordan Rift Valley

TABLE OF CONTENTS 1. EXECUTIVE SUMMARY .............................................................................................I 2. INTRODUCTION ........................................................................................................1 2.1. 2.2. 2.3. 2.4.

BACKGROUND & PROBLEM ANALYSIS ..............................................................1 OBJECTIVES .......................................................................................................1 METHODOLOGY AND MATERIALS ......................................................................2 SUMMARY OF ACTIVITIES UNDERTAKEN...........................................................3 A. Data Review ..................................................................................................3 B. Literature Review ..........................................................................................3 C. Conclusions & Recommendations.................................................................3

3. RESULTS ..................................................................................................................4 D. Water Quality Parameters and Yields...........................................................4 Salinity ......................................................................................................................................... 6 Calcium........................................................................................................................................ 9 Magnesium................................................................................................................................. 9 Sodium ......................................................................................................................................... 9 Potassium .................................................................................................................................. 10 Chloride ..................................................................................................................................... 10 Nitrates ....................................................................................................................................... 11 Sulfates ...................................................................................................................................... 11 Boron .......................................................................................................................................... 11 Copper ........................................................................................................................................ 12 Iron............................................................................................................................................... 12 Zink ............................................................................................................................................. 12 Manganese ............................................................................................................................... 12 E. Water Quality and Economic Returns.........................................................12 F. Water Quality and Public Health................................................................13 G. Water Quality and Marketing......................................................................13 H. Water Quality and System Maintenance .....................................................13 I. Soils .............................................................................................................14 Soil Chemical Data .............................................................................................................. 14 Soil Physical Data................................................................................................................. 15 J. Cropping Data.............................................................................................15 K. Plant Tissue Analysis...................................................................................16

iii

L. Climate ........................................................................................................16 M. Water Policies .............................................................................................16 4. DISCUSSION OF RESULTS.......................................................................................17 5. CONCLUSIONS & RECOMMENDATIONS ................................................................18 5.1. SUMMARY OF FINDINGS ..................................................................................18 5.2. WATER QUALITY PARAMETERS RECOMMENDED FOR TARIFF SETTING PURPOSES .................................................................................................................20 Salinity ....................................................................................................................................... 20 Microbiological Parameters ............................................................................................. 20 Chloride ..................................................................................................................................... 21 Nitrate and Phosphorus ...................................................................................................... 21 Trace Elements....................................................................................................................... 21 Suspended Solids .................................................................................................................. 21 pH and Bicarbonate ............................................................................................................. 21 Boron .......................................................................................................................................... 22 Sodium ....................................................................................................................................... 22 SAR ............................................................................................................................................. 22 5.3. ADDITIONAL ASSESSMENT PROJECTS AND MONITORING PROGRAMS .............22 Salinity ....................................................................................................................................... 22 Pathogens .................................................................................................................................. 23 Trace Elements....................................................................................................................... 23 Other Parameters................................................................................................................... 24 5.4. PROPOSED DIFFERENTIAL PRICING/TARIFF SYSTEM ACCORDING TO WATER QUALITY 24 5.5. PROPOSED WATER TARIFF EQUATION .............................................................25 5.6. INSTITUTIONAL AND POLICY REQUIREMENTS .................................................25 6. REFERENCES..........................................................................................................26 7. ADMINISTRATIVE ASPECTS ...................................................................................29

iv

2.

INTRODUCTION

The research carried out during this study aims at analyzing and reviewing the prospects for implementing a differential pricing/tariff system for irrigation water in the Jordan Rift Valley (JRV). The review and analysis results in recommendations for future study, monitoring and policy requirements that would pave the way to the successful implementation of an equitable tariff/pricing system. 2.1.

BACKGROUND & PROBLEM ANALYSIS

Agricultural water supplies in the Jordan Rift Valley (JRV) are limited and highly variable in quality. Population growth is resulting in re-allocation of these limited water supplies from agriculture to satisfy urban, commercial, and industrial demands in the highlands outside the JRV. However, most of the wastewater generated in the high lands is brought back to the JRV through the King Talal Reservoir (KTR), a major irrigation supply source. By 2025 it is expected that over 75% of KTR inflow will be of wastewater origin. Ultimately, parts of the JRV receiving pure KTR and blended KTR water will shift to reclaimed wastewater irrigated agriculture. Furthermore, in other parts of the JRV, waters of marginal quality are already being used and, similarly, their usage and associated deterioration is expected to continue. The use of treated wastewater and of other marginal water qualities in the JRV will have evident impacts on agriculture production and sustainability. Over the years, water quality deterioration in agricultural supplies would affect farmers’ ability to produce certain crops, market them, and sustain the productivity of their soils. The variability in quality of water supplies throughout the JRV without a pricing system that takes into account water quality variations is curtailing equity among farmers. Farmers receiving marginal water qualities reject the current pricing system and complain of additional costs incurred as a result of poor water quality. Such costs, at the farm level, include raised management levels, changing cropping patterns, increased irrigation system maintenance, marketing problems, and lost yield potential. 2.2.

OBJECTIVES

The main objectives of this research initiative are to: 1. Investigate the factors, at the policy and technical level, that should be considered for a differential water pricing/tariff system that is sensitive to water quality variations in the JRV; 2. Identify the data bases required to design an irrigation water tariff that is sensitive to water quality variations; 3. Identify additional monitoring programs in the JRV that are essential to implementing such a tariff (time series water quality monitoring, soil salinization and build-up of trace elements, plant toxicity, etc.);and 4. Define the required institutional tools to carry out and implement such a tariff program.

1

2.3.

METHODOLOGY AND MATERIALS

This study is based on available information and statistical data on water, soil and climate in addition to previous assessments and studies on water quality and its affect on agriculture. The assessments on how water quality, as a factor in production, can be considered in water pricing is mainly based on the effect of using water with impaired quality on agricultural production. Defining the price of different waters in the JRV according to their quality and hence productivity requires adequate knowledge about other natural resources (i.e. soils and climate) that also affect productivity. Rigorous field studies are required to accurately address the impacts of water quality on productivity and the interrelation between water quality, soils and climate. The natural factors affecting agriculture in the JRV (water, soil and climate) are reviewed and addressed in terms of their impacts on crop productivity in general terms as can be deduced from available literature on the subject. Local, regional and international literature is referenced at the end of this report. The factors affecting the agricultural productivity can be subdivided into two main categories: • Artificial: amount of applied water; frequency of irrigation; ploughing depths; fertilizer applications; biocides; cropping patterns; etc.; and • Natural: soil type/depth/structure/texture; climate; precipitation; land use history; and irrigation water biological/chemical and physical properties. In addition to considering the effect of water quality on productivity, soil productivity should also be considered in pricing water. Artificial or management related factors of productivity should remain out of consideration due to the variability and controllability of such factors. The two main factors of productivity that should be considered in developing waterquality based pricing systems and policies can therefore be limited to irrigation water quality, soils, and climate. These factors and how they impact yields, economic returns, public health, marketing, irrigation system maintenance and crop productivity in general should be assessed. A data review of available water, soil, and crop databases has been conducted. The validity and correctness of the data has been reviewed and data gaps identified. A literature review of previous studies on water qualities and its impacts in the JRV has also been conducted. Based on this work, conclusions and recommendations have been determined. With respect to the JRV, none of the numerous studies mention water quality as a parameter in defining differential water prices (Dietz, 1987; Dietz et al., 1993; PRIDE, 1992; NCARTT, 1993; MOA, 1996). Most of these studies discuss market liberalization for agricultural products and charging water prices to cover costs. Water costs as suggested by Dietz et al. (1993) and at present are still below 2% of the net farm income. Deloitte & Touche (1994) emphasize achieving optimum utilization and conservation of water resources through a set of action plans with the following issues being of relevance to this study: •

Assessing quantity and quality of brackish water;

2

•

Developing programs for groundwater utilization that would ensure its nondepletion; and

•

Setting water pricing policies which will ensure rational use of the commodity.

These statements indicate that water with impaired quality in the JRV should be dealt with in a different manner than “good” quality water when setting prices or when preparing water policies. 2.4.

SUMMARY OF ACTIVITIES UNDERTAKEN A.

DATA REVIEW

a) Review of available water, soil, and crop databases: •

Water quality parameters, soil chemical/physical data, cropping data, and plant tissue analyses.

b) Determine data validity and correctness: •

The data have been reviewed by experts for validity and correctness as representative data for the JRV.

c) Identify data gaps: Data gaps identified include areas where: •

Data seem invalid or non-representative of the location;

•

Monitoring and sampling frequency is insufficient to deduce representative data; and/or

•

There is a lack of data, either at an already sampled location or at a location that is thought to be important and that should be sampled.

B.

LITERATURE REVIEW

Previous studies on water qualities and its impacts in the JRV have been reviewed: •

The data used and potential impacts of different water qualities in the JRV that have been determined on yields, farmers’ economic returns, public health and marketing have been reviewed; and

•

The relationship between water quality and agricultural resources (irrigation systems, soils, etc.) in the JRV have been studied.

C.

CONCLUSIONS & RECOMMENDATIONS

a) The most important water quality parameters for tariff settings have been selected based on: •

The Literature Review (conclusions and recommendations of previous studies), the availability of data, and on what is thought to be vital and viable for inclusion into an equitable tariff structure.

3

•

The ability to spatially isolate water quality variations and the ability to identify water quality as the source of impact; and

•

The ability to determine and quantify potential impacts as a result of water quality and not of management practices, indigenous soil properties, external marketing factors, etc.;

b) Identify additional assessment projects and monitoring programs: •

This part is based on the data review and recommendations put forth in previous studies as determined from the literature review; and

•

The identification of the most important water quality parameters, will determine where and how monitoring is deficient and the parameters that need further investigation in terms of potential impact and viability for inclusion in an equitable tariff structure.

c) Recommend (if possible - depending on available data and analyses) a differential pricing for different water quality based on agreed scenarios: •

The impacts that can be inferred need to be quantified and translated into costs that can be related to concentrations of selected water quality parameters;

•

Points of water quality variations or areas that can be grouped according to water quality parameters and their associated impacts will be determined and water will be priced accordingly;

•

Coefficients or factors will also need to be determined for each water quality parameter in order to allow for adjustment of the tariffs with variations in water quality parameters over time.

d) Assess the institutional and policy tools required for implementation of such a tariff systems:

3.

•

The institution(s) designated for implementing such a tariff structure will likely require new or adjusted policies, training, sampling and analysis equipment, etc.;

•

Farmer education and awareness will also need to be addressed, another responsibility of the implementing institution(s).

RESULTS D.

WATER QUALITY PARAMETERS AND YIELDS

The Jordan Valley Authority (JVA) has collected data from various points along the King Abdullah Canal (KAC), wadis, and reservoirs that make up the irrigation system of the JRV. The JVA tests various physical and chemical water quality parameters that are of concern with agricultural supplies. The Water Authority of Jordan (WAJ) has collected water quality data at points where water is taken from the JRV irrigation system for municipal purposes in Amman and other areas. WAJ focuses on microbiological parameters that are of more concern

4

with municipal supplies but should also be considered for agricultural supplies with respect to public health, marketing and irrigation system maintenance. Laboratory analyses were carried out on a monthly and sometimes even on a daily basis for parameters such as EC and pH, and twice a year (during October and November) for most other parameters. The data collected have mainly been sampled and analyzed from 1990 through to 1997. WAJ and JVA have sampled and tested a number of water quality parameters including: • Calcium (Ca) • Boron (B) • Calcium & Magnesium • Chloride (Cl) (Ca+Mg) • Bicarbonate (HCO3) • Electrical Conductivity (EC) • pH • Sulphate (SO4) • Sodium Adsorption Ratio • Nitrate (NO3) (SAR) • Sodium (Na) • Total Heterotrophic Bacteria • Magnesium (Mg) • Total Coliforms • Potassium (K) • Fecal Coliforms Data on Total Heterotrophic Bacteria, Total and Fecal Coliforms are lacking for most areas of the JRV. Since WAJ only conducts monitoring for these parameters, they are only monitored at sites where water is destined for municipal purposes and not at sites where water is destined for irrigated agriculture. Irrigation water in the Jordan Valley originates from different sources such as the Yarmouk River, the side wadis, dams on side wadis, groundwater and spring water. According to the history of the water in these sources their qualities differ from good quality irrigation water to brackish or polluted water with high organic or specific components contents. Water chemistry affects the crop productivity of land. Hence the price of water should somehow reflect its agricultural productivity. In addition, good quality water resources in the Jordan Valley area are fully utilized; additional irrigation water can only come from sources with some quality constraints. Also the presently utilized water sources are becoming gradually more loaded with substances which may affect productivity. Therefore, it is necessary to assign different values (prices) for the different water sources according to their irrigation qualities as related to productivity. Following are the details of the effects of the different water quality parameters on agricultural productivity in areas with similar natural conditions as related to soils and climate. Several water quality parameters have been assessed for impacts on various crops worldwide. Some of these international assessments have been adapted and applied to the JRV. Research that is specific to the JRV on the effect of water quality on yield potentials has only been conducted for salinity. Yield potential calculations were based on the Maas-Hoffman salinity-coefficients (Maas and Grattan 1998). The calculations are also based on the relationship between ECw (electrical conductivity in the irrigation water) and ECe (average root zone salinity expressed as the EC of the saturated soil extract) assuming steady-state conditions and leaching fractions of 10%, 15-20% and 30% (Ayers and Westcot 1985). Yield potentials were determined for the major crops as well as non-traditional crops that have export potential by the method described above.

5

These yield-potential calculations for major crops, along with estimates of irrigation water requirements for crops in different regions, were used as components for economic analysis and crop budgets in an evaluation of grower’s economic returns. It was found that the yield potential for major crops varied considerably with irrigation water salinity, leaching fraction, and overall crop tolerance to salinity. Effects of Water Chemical Parameters on Crop Productivity Salinity Salinity in soils is caused by a variety of factors, such as irrigation water salinity, soil salinity, evaporation, soil texture, etc. Accumulation of salinity in the root zone area results in the inability of plants to extract the needed water amounts from the salty soil solution. As the salinity of irrigation water increases, the availability of water to plants decreases and the result is lowered productivity. The tables that follow (Table 1) gives general salinity tolerance ranges for different crops planted in the JRV (adopted from Maas and Hoffmann 1977, and Maas 1984). Table 1 Crop tolerance and yield potential of selected crops as influenced by irrigation water salinity (ECW) or soil salinity (ECe) FORAGE CROPS Wheatgrass, tall (Agropyron elongatum) Wheatgrass, fairway crested (Agropyron cristatum) Bermuda grass (Cynodon dactylon) Barley (forage) (Hordewn vulgare) Ryegrass, perennial (Lolium perenne) Trefoil, narrowleaf birdsfoo (Lotus corniculatus tenuifolium) Harding grass (Phalaris tuberosa) Fescue, tall (Festuca elatior) Wheatgrass, standard crested (Agropyron sibiricum) Vetch, common (Vicia angustifolia) Sudan grass (Sorghum sudanense) Wildrye, beardless (Elymus triticoides) Cowpea (forage) (Vigna unguiculata)

100%

90%

75%

0%

50%

“maximum”

ECe

ECw

ECe

ECw

ECe

ECw

ECe

ECw

ECe

ECw

7.5

5.0

9.9

6.6

13

9.0

19

13

31

21

7.5

5.0

9.0

6.0

11

7.4

15

9.8

22

15

6.9

4.6

8.5

5.6

11

7.2

15

9.8

23

15

6.0

4.0

7.4

4.9

9.5

6.4

13

8.7

20

13

5.6

3.7

6.9

4.6

8.9

5.9

12

8.1

19

13

5.0

3.3

6.0

4.0

7.5

5.0

10

6.7

15

10

4.6

3.1

5.9

3.9

7.9

5.3

11

7.4

18

12

3.9

2.6

5.5

3.6

7.8

5.2

12

7.8

20

13

3.5

2.3

6.0

4.0

9.8

6.5

16

11

28

19

3.0

2.0

3.9

2.6

5.3

3.5

7.6

5.0

12

8.1

2.8

1.9

5.1

3.4

8.6

5.7

14

9.6

26

17

2.7

1.8

4.4

2.9

6.9

4.6

11

7.4

19

13

2.5

1.7

3.4

2.3

4.8

3.2

7.1

4.8

12

7.8

6

Trefoil, big (Lotus uliginosus) Sesbania (Sesbania exaltata) Sphaerophysa (Sphaerophysa salsula) Alfalfa (Medicago sativa) Lovegrass (Eragrostis sp.) Corn (forage) (maize) (Zea mays) Clover,berseem (Trifoluimalexandrinum) Orchard grass (Dactylis glomerata) Foxtail, meadow (Alopecurus pratensis) Clover, red (Trifolium pratense) Clover, alsike (Trifolium hybridum) Clover, ladino (Trifolium repens) Clover,strawberry (Trifoluim fragiferu1)

2.3

1.5

2.8

1.9

3.6

2.4

4.9

3.3

7.6

5.0

2.3

1.5

3.7

2.5

5.9

3.9

9.4

6.3

17

11

2.2

1.5

3.6

2.4

5.8

3.8

9.3

6.2

16

11

2.0

1.3

3.4

2.2

5.4

3.6

8.8

5.9

16

10

2.0

1.3

3.2

2.1

5.0

3.3

8.0

5.3

14

9.3

1.8

1.2

3.2

2.1

5.2

3.5

8.6

5.7

15

10

1.5

1.0

3.2

2.2

5.9

3.9

10

6.8

19

13

1.5

1.0

3.1

2.1

5.5

3.7

9.6

6.4

18

12

1.5

1.0

2.5

1.7

4.1

2.7

6.7

4.5

12

7.9

1.5

1.0

2.3

1.6

3.6

2.4

5.7

3.8

9.8

6.6

1.5

1.0

2.3

1.6

3.6

2.4

5.7

3.8

9.8

6.6

1.5

1.0

2.3

1.6

3.6

2.4

5.7

3.8

9.8

6.6

1.5

1.0

2.3

1.6

3.6

2.4

5.7

3.8

9.8

6.6

100%

FIELD CROPS

90%

75%

50%

0% “maximum”

ECe

ECw

ECe

ECw

ECe

ECw

ECe

ECw

ECe

ECw

Barley (Hordeum vulgare)

8.0

5.3

10

6.7

13

8.7

18

12

28

19

Cotton (Gossypium hirsutum)

7.7

5.1

9.6

6.4

13

8.4

17

12

27

18

Sugarbeet (Beta vulgaris)

7.0

4.7

8.7

5.8

11

7.5

15

10

24

16

Sorghum (Sorghum bicolor)

6.8

4.5

7.4

5.0

8.4

5.6

9.9

6.7

13

8.7

Wheat (Tritticum aestivum)

6.0

4.0

7.4

4.9

9.5

6.3

13

8.7

20

13

Wheat, durum (Triticum turgidum)

5.7

3.8

7.6

5.0

10

6.9

15

10

24

16

Soybean (Glycine max)

5.0

3.3

5.5

3.7

6.3

4.2

7.5

5.0

10

6.7

Cowpea (Vigna unguiculata) Groundnut (Peanut) (Arachis hypogaea) Rice (paddy) (Oriza sativa)

4.9

3.3

5.7

3.8

7.0

4.7

9.1

6.0

13

8.8

3.2

2.1

3.5

2.4

4.1

2.7

4.9

3.3

6.6

4.4

3.0

2.0

3.8

2.6

5.1

3.4

7.2

4.8

11

7.6

Sugarcane (Saccharum officinarum)

1.7

1.1

3.4

2.3

5.9

4.0

10

6.8

19

12

Corn (maize) (Zea mays)

1.7

1.1

2.5

1.7

3.8

2.5

5.9

3.9

10

6.7

Flax (Linum usitatissimum)

1.7

1.1

2.5

1.7

3.8

2.5

5.9

3.9

10

6.7

Broadbean (Vicia faba)

1.5

1.1

2.6

1.8

4.2

2.0

6.8

4.5

12

8.0

Bean (Phaseolus vulgaris)

1.0

0.7

1.5

1.0

2.3

1.5

3.6

2.4

6.3

4.2

7

100%

VEGETABLE CROPS

90%

75%

50%

0% “maximum”

ECe

ECw

ECe

ECw

ECe

ECw

ECe

ECw

ECe

ECw

Squash, zucchini (courgette) (Cucurbita pepo melopepp)

4.7

3.1

5.8

3.8

7.4

4.9

10

6.7

15

10

Beet, red (Beta vulgaris)

4.0

2.7

5.1

3.4

6.8

4.5

9.6

6.4

15

10

Squash, scallop (Cucurbita peop melopepo)

3.2

2.1

3.8

2.6

4.8

3.2

6.3

4.2

9.4

6.3

Broccoli (Brussica cleracea botrytis)

2.8

1.9

3.9

2.6

5.5

3.7

8.2

5.5

14

9.1

Tomato (Lycopersicon esculentum)

2.5

1.7

3.5

2.3

5.0

3.4

7.6

5.0

13

8.4

Cucumber (Cucumis sativus)

2.5

1.7

3.3

2.2

4.4

2.9

6.3

4.2

10

6.8

Spinach (Spinacia oleracea)

2.0

1.3

3.3

2.2

5.3

3.5

8.6

5.7

15

10

Celery (Apium graveolens)

1.8

1.2

3.4

2.3

5.8

3.9

9.9

6.6

18

12

Cabbage (Brassica oleracea capitata)

1.8

1.2

2.8

1.9

4.4

2.9

7.0

4.6

12

8.1

Potato (Solanum tuberosum)

1.7

1.1

2.5

1.7

3.8

2.5

5.9

3.9

10

6.7

Corn, sweet (maize) (Zea mays)

1.7

1.1

2.5

1.7

3.8

2.5

5.9

3.9

10

6.7

Sweet potato (Ipomoea batatas)

1.5

1.0

2.4

1.6

3.8

2.5

6.0

4.0

11

7.1

Pepper (Capsicum annuum)

1.5

1.0

2.2

1.5

3.3

2.2

5.1

3.4

8.6

5.8

Lettuce (Lactuca sativa)

1.3

0.9

2.1

1.4

3.2

2.1

5.1

3.4

9.0

6.0

Radish (Raphanus sativus)

1.2

0.8

2.0

1.3

3.1

2.1

5.0

3.4

8.9

5.9

Onion (Allium cepa)

1.2

0.8

2.0

1.3

3.1

2.1

5.0

3.4

7.4

5.0

Carrot (Daucus carota)

1.0

0.7

1.7

1.1

2.8

1.9

4.6

3.0

8.1

5.4

Bean (Phaseolus vulgaris)

1.0

0.7

1.5

1.0

2.3

1.5

3.6

2.4

6.3

4.2

Turnip (Brassica rapa)

0.9

0.6

2.0

1.3

3.7

2.5

6.5

4.3

12

8.0

100%

FRUIT CROPS

90%

75%

50%

0% “maximum”

ECe

ECw

ECe

ECw

ECe

ECw

ECe

ECw

ECe

ECw

Date Palm (Phoenix dactylifera)

4.0

2.7

6.8

4.5

11

7.3

18

12

32

21

Grapefruit (Citrus paradisi)

1.8

1.2

2.4

1.6

3.4

2.2

4.9

3.3

8.0

5.4

Orange (Citrus sinensis)

1.7

1.1

2.3

1.

3.3

2.2

4.8

3.2

8.0

5.3

Peach (Prunus persica)

1.7

1.1

2.2

1.5

2.9

1.9

4.1

2.7

6.5

4.3

Apricot (Prunus armeniaca)

1.6

1.1

2.0

1.3

2.6

1.8

3.7

2.5

5.8

3.8

Grape (Vitus sp.)

1.5

1.0

2.5

1.7

4.1

2.7

6.7

4.5

12

7.9

Almond (Prunus domestica)

1.5

1.0

2.0

1.4

2.8

1.9

4.1

2.8

6.8

4.5

Plum, prune (Prunus domestica)

1.5

1.0

2.1

1.4

2.9

1.9

4.3

2.9

7.1

4.7

Blackberry (Rubus sp.)

1.5

1.0

2.0

1.3

2.6

1.8

3.8

2.5

6.0

4.0

Boysenberry (Rubus ursinus)

1.5

1.0

2.0

1.3

2.6

1.8

3.8

2.5

6.0

4.0

8

Strawberry (Fragaria sp.)

1.0

0.7

1.3

0.9

1.8

1.2

2.5

1.7

4.0

2.7

Calcium Usual Concentrations in irrigation water ranges from 0 - 20 meq/l (Ayers & Westcot 1985). Calcium deficiency causes disordered fruit and leaves. Calcium surplus results in lower productivity, but in decreased sodium hazards. Magnesium Usual concentrations in irrigation water ranges from 0 - 5 meq/l. Magnesium deficiency causes the green areas of leaves to form arrowheads and also decreasing productivity, surplus of magnesium results in lower productivity of plants, but at the same time it decreases sodium toxicity. Sodium Usual concentrations in irrigation water ranges from 0 – 40 meq/l. Severe restrictions for use in surface irrigation of more than 9 meq/l, moderate restriction for sprinkles of more than 3 meq/l. High concentrations of sodium are toxic to woody plants, such as stone fruits, citrus, vines and others, and result in declining productivity (its concentration is reflected in the water salinity). Excessive sodium in irrigation water leads to structural breakdown of soils and blockage of pore spaces, which in turn leads to root diseases and plant injury. The Sodium Absorption Ration (SAR) is used as a measure to predict the infiltration problems in soils. It is defined as: SAR Na (all in meq/l) 1/2 (Ca + Mg) 2 The recommended SAR values for irrigation water should be brought in a relationship to the salinity of the water (Table 2). Table 2 SAR and Restrictions on Irrigation in Relation to Water Salinity (ECw)

SAR 0–3 3–6 6 – 12 12 – 20 20 - 40

ECw (µS/cm) No Restrictions > 0.7 > 1.2 > 1.9 > 2.9 > 5.5

Slight

Severe

0.7 – 0.2 1.2 – 0.3 1.9 – 0.5 2.9 – 1.3 5.0 – 2.9

< 0.2 < 0.3 < 0.5 < 1.3 < 2.9

9

Potassium Usual range in irrigation water is 0 – 2 meq/l. Potassium deficiency cause marginal burns to leaves and reduce productivity. Potassium excess inhabits some crops from taking magnesium and calcium and hence reduces productivity. Chloride Usual range in irrigation water is 0 – 30 meq/l. Chloride is generally found in association with sodium in irrigation water. It is one of the major water components, which determine the salinity of the water. Excess concentrations of chloride cause injury to plants; Chlorosis (yellow leaves) progressing gradual to leaf burns and drying of tissues and to decreasing productivity (Table 3). Table 3 Chloride Tolerance of Some Fruit Crop Cultivars and Rootstocks (Maas, 1984) Crop

Avocado

Citrus (Citrus spp.)

Grape (Vitis spp.) Stone Fruits (Prunus spp.) Berries (Rubus spp.) Grape (Vitis spp.)

Rootstock or Cultivar

Maximum Permissible Cl-without Leaf Injury Root Zone (Cle) (meq/l) Irrigation Water (Cle) (meq/l)

West Indian Guatemalan Mexican Sunki mandarin Grapefruit Cleopatra mandarin Rangpur lime

7.5 6.0 5.0 25.0 25.0 25.0 25.0

5.0 4.0 3.3 16.6 16.6 16.6 16.6

Sampson tangelo Rough lemon Sour orange Ponkan mandarin

15.0 15.0 15.0 15.0

10.0 10.0 10.0 10.0

Citrumelo 4475 Trifoliate orange Cuban shaddock Calamondin Sweet orange Savage citrange Rusk citrange Troyer citrange Salt Creek, 1613-3 Dog Ridge Marianna Lovell, Shalil Yunnan Boysenberry Olallie blackberry Indian Summer Raspberry Thompson seedless Perlette Gardinal Black Rose

10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 40.0 30.0 25.0 10.0 7.5 10.0 10.0 5.0 20.0 20.0 10.0 10.0

6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 27.0 20.0 17.0 6.7 5.0 6.7 6.7 3.3 13.3 13.3 6.7 6.7

10

Lassen Shasta

Strawberry (Fragaria spp.)

7.5 5.0

5.0 3.3

Nitrates Nitrate is a plant nutrient, which stimulates crop growth. It is generally a positive addition to water used in irrigation. Excess quantities may lead to over stimulation of growth and to delay maturity or to bad quality of crops. The restriction on use may start by 30 mg/l (NO3 – N). Sulfates Generally found or precipitates from water as gypsum. Small concentrations of SO4 in water are beneficial to plants and soils up to 400 mg/l. Beyond that concentration, it becomes harmful and toxic to plants. However, the effects depend on other species in the water such as K, Mg and Carbonates. High gypsum contents may cause clogging of soil porosity. Boron Boron is an essential element for plant growth. The range of concentrations between the toxic level of boron and the nutrition needs is narrow. For the majority of plants the harmful concentration starts with 1mg/l. Concentrations of more than 2 mg/l in soil solutes are toxic to plants. Citrus plants, avocado and artichoke are very sensitive to boron (Table 4). Table 4 Relative Boron Tolerance of Agricultural Crops (Maas, 1984) Very Sensitive (< 0.5 mg/l)

Lemon Blackberry

Citrus Rubus spp.

Sensitive ( 0.5 – 0.75 mg/l)

Avocado Grapefruit Orange Apricot Peach Cherry Plum Persimmon Fig, Kadota Grape Walnut Pecan Cowpea Onion

Persea americana Citrus X paradisi Citrus sinensis Prunus americana Prunus persica Prunus avium Prunus domestica Diospyros kaki Ficus carica Vitis vinifera Juglans regia Carya illioniensis Vigna unguiculata Allium cepa

Moderately Sensitive (1.0 – 2.0 mg/l) Pepper, red Pea Carrot Radish Potato Cucumber

Capsicum annuum Pisum sativa Daucus carota Raphanus sativus Solanum tuberosum Cucumis sativus

Moderately Tolerant (2.0 – 4.0 mg/l)

Lettuce Cabbage Celery Turnip Bluegrass, Kentucky Oats Maize Artichocke Tobacco Mustard Clover, sweet Squash Muskmelon

Lactuca sativa Brassica oleracea capitata Apium graveolens Brassica rapa Poa pratensis Avena sativa Zea mays Cynara scolymus Nicotiana tabacum Brassica juncea Melilotus indica Curcubita pepo Cucumis melo

11

Sensitive (0.75 – 1.0 mg/l) Garlic Sweet potato Wheat Barley Sunflower Bean, mung Sesame Lupine Strawberry Artichoke, Jerusalem Bean, Kidney Bean, lima Groundnut/Peanut

Allium sativum Ipomoea batatas Triticum eastivum Hordeum vulgare Helianthus annuus Vigna radiata Sesamum indicum Lupinus hartwegii Fragaria spp. Helianthus tuberosus Phaseolus vulgaris Phaseolus lunatus Arachis hypogaea

Tolerant (4.0 – 6.0 mg/l) Sorghum Tomato Alfalfa Vetch, purple Parsley Beet, red Sugarbeet

Sorghum bicolor Lycopersicon lycopersicum Medicago sativa Vicia benghalensis Petroselinum crispum Beta vulgaris Beta vulgaris

Very Tolerant ( 6.0 – 15.0 mg/l) Cotton Asparagus

Gossypium hirsutum Asparagus officinalis

Trace elements Copper Sensitive plants are negatively affected by a concentration of 25-30 mg/l of copper, but most plants tolerate 150 mg/l. With copper deficiency leaves may die off fertilization may fail and fruits may be strongly deformed. Iron Toxicity to plants depends on soil aeration. If oxygen is available in irrigation water no harmful effects are to be found. If the SAR of the water is high > 6, high iron concentration > 3 mg/l may be harmful to some plants. Zinc Zinc is an essential micronutrient to plants. Too high a concentration may be harmful to fruit trees. Manganese Only at high concentrations (> 1 mg/l), manganese can become harmful to plants. Well-aerated soils and normal water pH values do not cause manganese toxicity. E.

WATER QUALITY AND ECONOMIC RETURNS

FORWARD (1999) has evaluated water quality impacts on yield potentials according to agreed approaches to calculate yield potentials, the percentage leaching fractions, assumed irrigation efficiencies; and crop water use figures. The impact of salinity on the profitability or growers’ economic returns from selected crops at the ten stage 12

offices in the JRV has been assessed and is available in a simple spreadsheet model format. The quantitative assessment looks at four salinity levels as delineated according to salinity variations. Four areas of water quality were used for various reasons including irrigation supply sources, water quality data and the irrigation network among others. Salt sensitive high-value crops such as grapes, cucumbers and bananas are most affected, while more salt tolerant crops such as wheat show almost no loss in income upon substitutions to more saline waters. F.

WATER QUALITY AND PUBLIC HEALTH

The primary constraint to any project proposing to use wastewater is public health. The threat to human health can come from four pathogen groups: viruses, protozoa, bacteria, and helminthes. Wastewater, especially domestic wastewater, contains pathogens that can spread disease when managed improperly. FORWARD (1999) has looked at the limited data that are available and suggests sources of contamination. Also reviewed, against internationally accepted guidelines, are several Jordanian Standards regarding these water quality parameters. Recommendations for monitoring and remediation are also given. G.

WATER QUALITY AND MARKETING

Water quality and marketing has been looked at in terms of yields and public health (consumer confidence). Yields have been assessed to determine potential losses in market windows or marketing potential as a result of water quality. Public health aspects are reviewed, with examples of losses that have resulted from a loss in consumer confidence and markets as a result of certain policies. The study also showed that Jordan has an exceptional competitive advantage in producing off-season high-value crops that require high quality water. This advantage would be lost if water quality deteriorates and consumer confidence is lost. In 1995, the Government of Saudi Arabia stopped the import of vegetables from Jordan claiming that they are irrigated with untreated wastewater. The decision was based on an analysis of water samples from KTR that confirmed the existence of several pollutants in the irrigation water. The accrued losses were estimated at JD 23.2 million. The actual losses are expected to be even higher than this estimate.

H.

WATER QUALITY AND SYSTEM MAINTENANCE

The data available on the water quality parameters that were assessed in terms of irrigation system maintenance include pH, bicarbonate (HCO3); nitrate (NO3); and calcium (Ca). The analyses focus on drip irrigation systems at the farm level, the maintenance problems associated with suspended solids, pH and chemical clogging of emitters, and clogging that may result from nutrients and algae. The JVA delivery system is also discussed since it provides water to the systems at the farm level. The maintenance of sprinkler and other methods of irrigation are not as problematic; the use of these irrigation methods is far less popular than drip systems in the JRV.

13

I.

SOILS

Soils are generally a product of geology, climate, topography and history of use. The JRV floor is recent geological feature of the earth surface and therefore its soils are recent. They generally developed on alluvial deposits with very weak profile development, but nonetheless, they show substantial variations in their textures, thickness and humus contents along the Jordan Valley. The productivity of natural soils is a function of the following major factors: 1. Soil thickness:

0 – 20 cm 0 – 50 cm > 50 cm

2. Availability and thickness of humus layer:

Missing 5 – 10 cm 10 – 15 cm > 15 cm

3. Drainage

Well drained Drained Partly drained Not drained

4. Salt Content

Low Medium High Very high

5. Soil Texture

Sandy Loamy calcareous Permeable Depth to the marly layer…etc.

3000 µs/cm

Soil Chemical Data The JVA laboratory provides records of soil data that include chemical analyses conducted since 1985 on different farm units. Some soil samples were taken as a part of various projects from 1985 onwards. Thus, the number of soil samples taken from different areas varied from year to year. Furthermore, samples may not be taken from the same farm unit during subsequent years. Soil data has been grouped according to depth as follows: • 25 cm to represent samples taken from 0-30 cm depths; • 50 cm to represent those of 30-60 cm depth; • 75 cm represents those of 60-100 cm; • 100 cm to represent those depths more than 100 cm; and • 150 cm to represent samples deeper than 125-150 cm. Statistical analyses have been carried out for various soil parameters represented by samples at the various depths according to time series. Several records are lacking

14

either in the development area number or farm unit where sampling has been conducted. Soil Physical Data Soils vary substantially in texture, thickness, and humus contents throughout the Valley. The thickest soils occur in the northern parts of the Valley, decreasing in thickness southwards towards the Dead Sea along with decreasing precipitation rates. The soils are generally low in organic content, in some places they contain high gypsum contents and are calcareous in others. Soils have been classified for land use purposes by Tueimeh et al. (1993). However, the data and classification carried out is insufficient to incorporate variability in JRV soils into an equitable tariff system. The data required would include permeability, salt profiles, texture etc. Soil productivity would also depend highly on management practices, which are highly variable, as are the indigenous soil properties. The areas with drainage systems installed are available from the JVA. The entire irrigation system is mapped and represented schematically. The FORWARD team prepared this schematic in coordination with staff from the Ministry of Water and Irrigation (MWI), the Water Authority of Jordan (WAJ), and JVA. The schematic depicts reservoirs, stage offices, turn out assemblies, diversions, the KAC, and how irrigation water flows between them. In the framework of studying the soils of Jordan, soil surveys in the JRV were carried out. The aim of these studies was to classify the soils for land use purposes (The Soils of Jordan, Ministry of Agriculture, 1993, Tueimeh, Salameh and Rimawi, soils and irrigation water in the Jordan Valley area 1989, University of Jordan). The general classification of soils in the Jordan Valley for pricing irrigation water is available from available studies. However, the detailed information to reach at a just pricing policy is not available and must be carried out through the collection and evaluation of scattered data and reports and through acquiring new data. Man-made changes to the soil characteristics represent also a major factor in soil productivity. Such changes include water logging or drainage, flushing or accumulation of salts in soil profiles, opening or destroying of soil porosity, etc. Other parameters that are relevant to the pricing are eutrophic state of water bodies, oxygen content, saturation state of calcite gypsum, etc. Information on such parameters are available or can be worked out, although for pricing purposes more detailed analyses are required to work out the effects of such parameter concentration on land productivity. J.

CROPPING DATA

Data on cropping patterns are available from the JVA. The data are on a monthly basis for each crop in each stage office and cover the years 1995, 1996, and 1997. Data on yields are available from the Department of Statistics (DOS) for major crops in each area based on production/area. These data are available as averages for major crops. Crop specific water requirements have been determined through a review of appropriate studies on crop water requirements and were slightly adjusted to the specific conditions of the JRV using published data on crop water requirements grown 15

in similar areas. However, since soils and climate play an important role in determining crop water requirements, and these conditions, especially soils, vary considerable throughout the JRV, crop water requirements were determined separately for different areas of the JRV. Crop water requirements are therefore available for the North, Middle, and South Directorates. These levels of water requirements, for selected crops, were estimated in full collaboration between the researchers of MWI and the National Center for Agricultural Research and Technology Transfer (NCARTT). K.

PLANT TISSUE ANALYSIS

Plant analyses have been conducted for various types of crops. Sampling and analysis is not part of a systematic monitoring program, but rather sporadic or conducted for localized programs that continued for short periods. The analyses covered a wide range of plants including fruit trees and vegetables. The analyses were also conducted on various plant parts such as leafs, stem, and/or fruit. Plant analyses were distributed according to Stage Office, Development Areas, and Land Class to indicate the soil from which the plant samples were taken. L.

CLIMATE

The prevailing climatic conditions in the JRV allow it to be classified as hot semiarid, but there are still some variations between its different parts in the context of agricultural productivity: The northern part with an annual average precipitation of 300-400 mm/yr, and a potential evaporation of 200-2200 mm/yr. The middle part with an annual average precipitation of 200-300 mm/yr and a potential evaporation of 2200-2350 mm/yr. The southern part with an annual average precipitation of 100-200 mm/yr and a potential evaporation of 2350-2450 mm/yr. Precipitation water is of excellent quality for soils and hence for soil productivity. Therefore, it should be taken into consideration when assigning prices for supplementary irrigation water. M.

WATER POLICIES

The Government of Jordan has expressed concern over continuing degradation of water quality in the Kingdom and the impact of variations in irrigation water quality in the JRV. MWI has recently changed its water policy to state that wastewater treatment should allow for “unrestricted agriculture” and that considerations shall be given to blending treated effluents with fresher water for appropriate reuse. Blending is an alternative that gives all users the same economic advantage as they all start with the same water supply. An equally good alternative is to consider water pricing or water subsidies to make it economically attractive for farmers to utilize poorer water qualities for their main supplies. The MWI Irrigation Policy recognizes the impact of marginal water quality and calls for informing farmers of the potential quality of irrigation water so that their choice of crops and farm management is made with the appropriate background information 16

and knowledge. The Irrigation Policy also states “differential prices can be applied to irrigation water to account for its quality.” The Wastewater Management Policy addresses crop selection based on irrigation water, soil types and chemistry, and the economics of reuse operations. Water allocation and reallocation remain the responsibility of MWI. In recent years, JVA water has been reallocated from agricultural use to urban uses under WAJ based on social, economic, and environmental considerations. Because tariffs are not based on actual costs, little attention is given to matching the costs of producing water for particular uses to the authority responsible for supplying that use. The Jordan Water Strategy also gives first priority to the allocation of water to the basic human needs; as such first priority is given to domestic water supplies (Article 16). To accomplish this in Jordan, a water short country, a proposal has been implemented to: transfer good quality water from the agricultural sector to urban uses; and return treated wastewater to the agricultural sector to replace the water transferred to the urban sector. The Jordan Water Strategy allows treated wastewater to be used as an irrigation resource (Article 12) but stipulates that the treated wastewater should allow sustainability of irrigated agriculture (Article 17). Article 12 stresses that the treated wastewater diverted to the agriculture sector allow unrestricted agriculture and that appropriate treatment technologies be used to achieve this. Because of an emphasis on ensuring that water quality does not limit agriculture, Article 12 also calls for blending of the treated wastewater with fresher water, if needed, to accomplish this goal.

4.

DISCUSSION OF RESULTS

The study considers the different water, soil and climatic parameters as natural agricultural inputs, which affect productivity of crops in the JRV and hence the differential price policies there. Assigning a price for water according only to water quality will be neither fair nor appropriate because the other natural input parameters; soil and climate have to be considered, because they greatly influence productivity. For example, the northern part of the Jordan Valley area receives an average amount of rainfall of 300-400 mm/yr, compared to the southern part that receives only about 100 mm/yr. This fact indicates that lands in the southern part require not only a larger amount of water per unit land to produce the same amount of product but also a better quality irrigation water to compensate for the lager amount of “salt free” rain water falling over the northern part. These same two areas have also different soil types and indigenous salinity. In the northern part soils are composed of limestone and basalt residues which are flushed of salts and do not show any signs of salinization. Contrary to that are the soils of the southern parts composed of salty marl residues (Lisan Formation) and which show accumulation of salts due to poor irrigation and drainage provisions. By considering the input resources parameters, which affect crop productivity an equation can be developed for water, pricing that accounts for quality constraints. Since land productivity is inversely related to irrigation water salinity, sodium 17

adsorption ratio and soil extract salinity; and directly proportional to oxygen content, porosity, good soil texture and rainfall an equation governing water pricing should follow a similar form. The parameters of such an equation still have to be worked out in a detailed study to fill the gaps of information, and to produce the necessary maps with these parameters as natural inputs into the production system. The agricultural policy charter (MOA, 1993) identified that irrigation water in the JRV as the most serious constraint to agricultural growth. There is increasing realization that despite improvements in the productivity of irrigated agriculture, input resources allocation efficiency is still lagging considerably behind technological adaptation (MOA 1993, PRIDE 1992, Dietz et al. 1993). The survival of much of the Jordan Valley crops will certainly depend on the availability of irrigation water, its efficient use and pricing according to its cost, but while also taking into consideration among other parameters its quality as a major parameter affecting productivity. Efficient use requires the detailed knowledge of the water, soil and climate parameters, which affect crop productivity. The development and utilization of these production resources for efficiency and optimality should be based on quantity, quality, and equity among farmers. This then should lead to maximize economic returns as well as to sustainability and conservation of the environment. Putting different prices to the different waters, as a natural input parameter in irrigated agriculture will allow JRV farmers to compete with each other in a fair way. Such price setting in the JRV area is also inflicted with problems, such as water subsides (still the norm), cost of conveyer systems (capital, and operation) and dictation of cropping patterns. Under any circumstances, pricing systems should aim at equity among farmers and should serve as incentive for production and not as a punishment.

5.

CONCLUSIONS & RECOMMENDATIONS

5.1.

SUMMARY OF FINDINGS

Natural productivity of land is a function of rainfall, evaporation, soil thickness humus content, drainage, soil salt content, soil texture, water salinity, SAR, boron concentration, and specific water chemical parameters. In the context of water chemistry water in the JRV can be categorized as follows: •

Water with a salinity of up to 1500µs/cm and SAR of less than 6; Water from the Yarmouk River, Ziglab, Wadi Arab Dams, Kafrain Dam, some groundwater wells and the side wadis (best category).

•

Water with a salinity of 1500-2500µs/cm and SAR of less than 6; King Talal Dam water, Shueib Dam, groundwater in the southern and western parts of the Jordan Valley, including some of Kafrain deep wells and all Zara springs.

•

Water with a salinity range of 2000 – 3000µs/cm with a SAR of more than 6; These include some of Rama Kafrain deep wells and all Zarqa Main springs.

18

•

Water with a salinity of more than 3000µs/cm and a SAR of more than 6; some of Karain, Rama Hisban deep wells, a few wells in the area of Karama, Wadi Mallaha springs and Deir Alla, Abu Ziegan springs.

•

Treated wastewater: generally, this type is mixed with other water sources in different ratios. This type shows salinity range of 1800-3000µs/cm is rich in organic matter and has a SAR of less than 6; King Tala Dam water, Kufranja effluents, Wadi Shueib and Shueib Dam water, Wadi Kafrain and the diverted effluent of Wadi Arab wastewater treatment plant.

Table 5 Summary of Irrigation Water Parameter Guidelines (University of California, Committee of Consultants 1974) Potential irrigation Problem

Units

Degree of Restriction on Use None Slight to Moderance

Severe

Salinity (affects crop water availability) ECw (or) TDS

ds/m

< 0.7

0.7 – 3.0

> 3.0

mg/l

< 450

450 – 2000

>2000

> 0.7 > 1.2 > 1.9 > 2.9 > 5.0

0.7 – 0.2 1.2 – 0.3 1.9 – 0.5 2.9 – 1.3 5.0 – 2.9

< 0.2 < 0.3 < 0.5 < 1.3 < 2.9

SAR

9

Chloride (Cl) Surface irrigation Sprinkler irrigation

me/l me/l

10

Boron (B)

mg/l

< 0.7

0.7 – 3.0

> 3.0

mg/l

30

mg/l

< 1.5

1.5 – 8.5

> 8.5

Infiltration (affects infiltration rate of water into the soil. Evaluate using ECw and SAR together) SAR 0 – 3 and ECw 3– 6 6 – 12 - 12 – 20 - 20 – 40 Specific Ion Toxicity (affects sensitive crops) Sodium (Na) Surface irrigation Sprinkler irrigation

Miscellaneous Effects (affects susceptible crops) Nitrogen (NO3 – N) Bicarbonate (HCO3) (overhead sprinkling only) pH

Normal Range 6.5 – 8.4

19

Concerning rainfall the Jordan Valley can be subdivided in three sub-areas: • 100-200 mm/yr. • 200-300 mm/yr. • 300-400 mm/yr. Concerning evaporation area subdivisions, the same areas of precipitation can be used, where evaporation in areas I>II and >III. Concerning soils, thickness humus content, drainage, soil texture and soil salt contents, the Jordan Valley area can be subdivided into three sub-areas which somehow correspond to the rainfall/evaporation sub-areas: •

The area extending from the Yarmouk River to Deir Alla (best category).

•

The area extending from Deir Alla to Rama-Kafrain in a north-south direction and from the mountain foothills in the east to a line 3-4km east of the Jordan River course (intermediate category).

•

The area extending from Deir Alla to the Dead Sea, between the Jordan River course and a line 3-4 km further east (worst category).

5.2.

WATER QUALITY PARAMETERS RECOMMENDED PURPOSES

FOR

TARIFF SETTING

Salinity Irrigation water salinity, or ECW, should be incorporated into a water quality-sensitive tariff system. ECW varies significantly throughout the JRV and the impact on yields and consequently on growers’ economic returns has been demonstrated quantitatively. ECW also plays a role in determining cropping patterns and other aspects of farm management. The long-term impact of ECW on soil salinization is not as explicit due to the highly variable nature of soils and management practices that affect leaching and drainage. However, ECW should be taken into consideration in the restructured tariff. Microbiological Parameters Although, based on available data and FAO/WHO guidelines, it seems that KTR water can be used for unrestricted irrigation most of the time, the present conditions produce water of marginal quality that raises concerns for public health and safety. This concern can quickly grow to a lack of public confidence, both nationally and internationally. In addition the vulnerability of the irrigation supply will increase in the future as larger portions of that supply will be made up of wastewater. There are also signs of secondary contamination in other portions of the KAC, making this parameter a concern throughout the whole JRV as well as areas irrigated with pure and blended KTR water. A very high risk is associated with pathogens, which makes this water quality parameter essential for consideration in a restructured tariff system. In addition, there are many methods for alleviating the risk associated with microbiological

20

contamination, including, monitoring and regulating water applications, enforcing wastewater discharge standards and correcting sources of contamination among others. Chloride Chloride and its associated toxicity problems vary from area to area and is associated with high risk due to its potential impact on trees and vines, which make up considerable portions of the cropping patterns in the JRV. The variations in irrigation supplies are explicit enough for viable consideration into a water quality-sensitive tariff structure. Chloride levels also limit the use of sprinkler irrigation. However, by the time chloride injury is evident in certain crops, these plants are already experiencing severe salinity stress. Nitrate and Phosphorus In almost all natural water supplies, nitrogen, mostly present in the nitrate form, supplied by irrigation water is an insignificant portion of the total nitrogen requirement of the crop. Data on nitrates in KTR water are insufficient to conclude that nitrogen availability in these waters is a valuable resource. Furthermore the nitrogen and phosphorus content in irrigation waters is not constant and would require continuous monitoring and adjustments if incorporated into a water pricing/tariff structure. It is also difficult to control the timing and quantity of nutrient availability in water supplies (late season nitrogen applications could result in yield losses or delayed maturity). The farmer may also doubt the availability of these nutrients in irrigation supplies, and if for any reason there are losses in yields, the irrigation water will be the focus of dispute. Nitrogen and phosphorus can also incur maintenance costs due to weed growth and system clogging. In light of the above, it is recommended that nitrate and phosphorus not be considered at this stage into a restructured tariff system. Trace Elements Trace elements potentially pose a high risk, but the levels in the JRV are low to medium. The present levels of trace elements in KTR water do not present a potential to limit crop production or limit short or long term soil productivity as a result of accumulation. Therefore it is not recommended that this water quality parameter be considered for tariffs at this stage. Suspended Solids It is not recommended that suspended solids be considered in a restructured tariff since this parameters impact on irrigation system maintenance can be easily controlled, either centrally or at the farm gate. Furthermore, the variations in sediment loads in the irrigation waters and the associated maintenance problems do not vary significantly from area to area within the JRV. pH and Bicarbonate pH is low in risk, however, it may be seen to cause system maintenance problems, especially when KTR water is used. In addition, variations in pH and bicarbonate 21

levels do not vary significantly from area to area within the JRV. Until an evaluation of pH and the extent of problems and costs related to pH, and chemical clogging, as a result of calcium carbonate precipitation, these parameters should not be used to determine water pricing structures in the JRV. Boron Although Boron is likely to be problematic for most fruit trees and vines, especially with poorer quality water, it is not likely to be as restricting as salinity and chloride. In general, the Boron concentrations in all of the irrigation water supplies have been reduced over the years to low levels as a result of certain policy implementations. Boron availability to plants may also be more related to organic loads rather than water supplies or indigenous soil properties. Based on this information and the relatively low Boron concentrations found in the natural water supplies used to irrigate the Jordan Valley, it is not recommended that this parameter be considered in developing water pricing. Sodium Sodium often produces specific ion toxicity in addition to causing potential problems related to soil structure. There are, however, no clear cut guidelines indicating sodium concentrations in irrigation waters that produce injury to crops, except for when sprinkler irrigation is used, as a result of numerous factors that can affect this water quality parameter’s availability. Based on this information, it is not recommended that sodium be considered in developing water pricing. Should sprinkler irrigation become a dominant practice in the future, this recommendation may have to be modified. SAR The Sodium Adsorption Ratio (SAR) is the primary indicator of a Sodicity hazard or a permeability hazard, but this hazard can also be influenced by the salinity of the water supply. The SAR for most irrigation waters in the JRV are low. The combined effect of high calcium in water supplies and in soils as a result of indigenous soil properties works further to reduce the SAR and associated hazards. The effects of SAR on soil salinization are highly variable and depend on farm management practices as well as on ECw. Based on this information, it is not recommended that SAR be considered in determining water pricing in the Jordan Valley. 5.3.

ADDITIONAL ASSESSMENT PROJECTS AND MONITORING PROGRAMS Salinity

Salinity has the highest potential to impact crop production and economic viability within the JRV. There are numerous methods to manage a salinity problem at the farm level, but the JVA needs to take steps to ensure that farm level techniques will succeed. Therefore the JVA should consider assessment projects that look at: •

Upgrading the irrigation delivery system to increase the ability to provide water on demand for leaching purposes;

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•

Analyzing the need to develop system management and cropping patterns that more closely fit the wastewater flows expected in the future;

•

Studying how it can upgrade its system reliability, including real time management of salinity and flow, since the farmers need to know the level of salinity in the water received;

•

Studying the need to consider newer salinity control techniques, including cyclic irrigation of higher and lower salinity waters;

•

Ensuring that subsurface drainage is considered as part of any salinity management plan; and

•

Studying the long-term impacts of salts on groundwater quality. Pathogens

The risk from pathogens associated with public health presents a great threat to longterm agricultural production in the JRV. Wastewater can be safely used, provided that it complies with international standards and regulations, but it must be done in a way that results in a high level of public/consumer confidence. JVA and WAJ will be asked in the future to consider crop and worker safety with the water supplies they deliver. To begin this process, the following steps should be considered: •

Develop wastewater treatment capabilities that provide a consistently safe wastewater supply that is acceptable for unrestricted irrigation use.

•

Focus on fecal coliforms as the evaluation parameter.

•

Conduct a thorough sanitary survey of the JVA distribution system and remove all sources of secondary contamination.

•

Debate the merits of a national policy of isolating wastewater to selected areas vs. the present policy of dispersion of the wastewater (mixing with fresh waters) throughout the irrigation delivery system.

•

Develop agricultural extension service’s capacity to manage the reuse areas, including consideration of using cropping restrictions and incentive programs to promote safe production areas. Trace Elements

As no evaluations of trace elements accumulation have been conducted in the JRV, a long term monitoring program is recommended. To ensure that the potential high relative risk remains low the following should be considered: •

Policies that declare that the soil in wastewater reuse areas is a resource to the country and trace element concentrations should be kept at a level that ensures that the soil resource do not suffer from irreversible damage;

•

Monitor the KTR discharge on a periodic basis with special consideration to lead, copper, molybdenum, nickel, and zinc since each showed elevated levels, although, within acceptable limits. Soil should be monitored periodically for boron accumulation in areas where the irrigation water supply approaches or exceeds the 0.7 mg/l threshold. This is particularly important in areas planted with trees and vines.

•

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Other Parameters In the future when KTR water is expected to make up a significant portion of the total flows, the nutrient levels, especially nitrogen, will increase in importance calling for a monitoring program that focuses on total nitrogen to be implemented. The extent of problems and costs related to pH and chemical clogging, as a result of calcium carbonate precipitation, in emitters needs to be determined and evaluated for the KAC as well as KTR waters. 5.4.

PROPOSED DIFFERENTIAL PRICING/TARIFF SYSTEM ACCORDING WATER QUALITY

TO

Based on the available data and analyses carried out in the JRV a potential pricing/tariff system that is sensitive to water quality can only include salinity, chloride and pathogens. Soil productivity factors and other water quality parameters could be included at a later stage once more data and analyses become available. Ultimately a water pricing structure should be developed that takes into account the following parameters and their associated impacts. Some of these parameters have been assessed in terms of their impacts however, others are lacking in data availability, spatially and temporally, in addition to a lack of hazard or impact assessment. Upon subsequent assessments and provision of data, it may prove difficult or non-viable to incorporate all of these parameters and their associated impacts: Water Quality Parameters

Potential Impact and Hazard

Physical and Chemical Salinity/electrical conductivity

Yield reduction, growers’ economic returns, marketability, soil salinization, permeability hazard

Sodium

Crop toxicity, permeability hazard

Sodium Adsorption Ratio

Permeability hazard

Nitrate

Nutrient availability, irrigation system maintenance, on-farm management

Phosphorus

Nutrient availability, irrigation system maintenance, on-farm management

Bicarbonate

Irrigation system maintenance

Boron

Crop toxicity, soil accumulation

Chloride

Crop toxicity, soil accumulation

pH

Irrigation system maintenance

Trace elements (and special attention to Zn, Mo, Cu, Pb & Ni)

Crop toxicity, public health, soil accumulation, consumer confidence

Suspended solids

Irrigation system maintenance

Microbiological Total/fecal coliforms

Public health, consumer confidence

Heterotrophic bacteria

Public health, consumer confidence

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Nematodes

Public health, consumer confidence

Factors that depend highly on management practices, both at the farm level and entire irrigation network level, should not be incorporated into a tariff structure. Rather equity should be achieved, when taking into account such factors, through other methods including, rehabilitation, policies, training, and farmer extension education. 5.5.

PROPOSED WATER TARIFF EQUATION

If the different natural parameters are to be considered in setting the tariff in order to reach equity among farmers then the proposed equation should follow: Water Price =

+

a Salinity

+

b SAR

+

c * nutrient content + d * rainfall

e + f + g * amount of water use Soil Salinity Soil - SAR planted area

Where the factors (a) to (g) need to be worked out in more detailed studies and comprehensive farm analyses. 5.6.

INSTITUTIONAL AND POLICY REQUIREMENTS

Some of the fresh water resources in the Jordan Valley are being reallocated to meet the municipal and industrial demands in the Jordan Valley and in the highlands. Moreover, additional marginal waters including wastewater are being used for agriculture. Such a shift in water quality in some areas in the valley has caused difficulties to the farmers and the supplier (Jordan Valley Authority). Recent variations in water quality parameters were not carefully anticipated in the past; the supply of water was mainly driven by quantity considerations. The increasing amounts of wastewater into the system were not planned for reuse in a manner that integrally considers soils, crops, water, and climate. Historical farming patterns that started with fresh water sometime ago cannot survive changes in quantity and quality parameters. Extension services that are based in the Ministry of Agriculture were insufficient to cope also with the changes. “Business as Usual” in farming in the valley can lead to national losses at many levels. Farmers may witness sever losses if current practices continue and the water utilities might not be able to cover their costs from farmers. Soils degradation might also intensify and spatially extend to other areas, and farming systems in general might be affected. Given the nature of irrigation tariff structures based on water quality variations, the following policy-related issues need to be revisited continuously: •

Water quality parameters that should be used for tariff setting. Salinity, pathogens, and chloride are recommended for initial consideration in irrigation tariff setting. However, due to potential future changes in water resources and their qualities additional parameters might need to be considered in tariff setting;

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6.

•

Monitoring programs needed in the Jordan Valley. Monitoring of water, soils, and plants in the Jordan Valley are essential for tariff setting. The parameters that should be monitored and monitoring frequency have to be determined based on clear objectives for tariff setting purposes;

•

Other policy issues that affect farming, water quality, and tariffs. Given the increasing contribution of treated wastewater into the JVA irrigation water budgets and the reallocation of fresh water to urban uses, the viability of wastewater mixing polices versus isolation for different farming practices and crops should be investigated. Other government policies related to marketing, tax protection of certain crops and subsidies among urban and agriculture uses among other factors should also be assessed; and

•

Willingness and ability of farmers to pay for irrigation water. The Jordan Valley farms structure contains different sized farms, technologies, cropping patterns, water qualities, marketing processes, etc. In lieu of these factors, the ability and willingness of various farmers in the Jordan Valley to pay for irrigation water should be studied.

REFERENCES

The list of references below include some of the reports and studies reviewed. Additional references are given that may also prove helpful in future studies or assessments related to the work carried out. • • • • • • • • •

Ayers, R. S. and D.W. Westcot. 1985. Water Quality for Agriculture. FAO Irrigation and Drainage Paper #29, Rev 1. Food and Agricultural Organization. Rome. 174pp. Bahri, A. 1997. Reclaimed Water Reuse for Irrigation in the Amman-Zarqa Area of the Jordan Valley. Report to the World Bank. Washington, D. C. Delloitte & Touche (1994): Structural adjustment and policy support project, CIDA and MOWI, Amman. Dietz, M. (1987). A report on a short term secondment to The Jordan Valley Authority for the collection and use farm data economics. Dietz, M., W. Hannover, & G. Lindauer (1993). Assessment of the potential impact of agricultural adjustment measures as proposed by ASAL on farmers income, Amman , Frankfurt (BMZ). Dietz, H. M. 1996. Development of a Quality Assurance System for Fruit and Vegetable Production in Jordan. Report to the Agricultural Marketing Organization, Amman. FAO. 1993. Control de Aguas de Riego Destinadas a la Produccion Hortofruticola: Chile. Technical Report of Project TCP/CHI/2251(A). FAO. Rome. FORWARD 1999. Assessment of Water Quality Variations in the Jordan Valley. Volumes 1-5 GIBB. 1997. Feasibility Study for Storage Facilities in the Wadi Mallaha, Karamah Dam Project. 1997 Review. Sir Alexander GIBB & Partners. The Hashemite Kingdom of Jordan.

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•

• • • • • • •

• •

• • • • • •

Grattan, S.R. and J. D. Rhoades. 1990. Irrigation with Saline Ground Water and Drainage Water. In: Agricultural Salinity Assessment and Management. K.K Tanji (ed.). Prepared by the Water Quality Technical Committee of the Irrigation and Drainage Division of the American Society of Civil Engineers. ASCE Manuals and Reports on Engineering Practices 71, ASCE, New York, pp 432449. GTZ. 1995. Appraisal Report: Sustainable Use of Brackish Water for Irrigated Agriculture in the Southern Jordan Valley. Hagan, R. E. and Taha, S. S. 1997. Irrigated Agriculture in Jordan: Background Paper. Water Quality Improvement and Conservation Project. Report 3114-973b-19. Hanson, B.R., L.J. Schwankl, S.R. Grattan, and T. Prichard. 1994. Drip Irrigation of Row Crops. University of California Irrigation Program. University of California, Davis, CA 175pp. Harza. 1996. Master Plan and Feasibility Study for Rehabilitation, Expansion and Development of Existing Wastewater Systems in Amman-Zarqa River Basin Area. Prepared for the Ministry of Water and Irrigation, Amman, Jordan. IRCWD. 1985. Health Aspects of Wastewater and Excreta Use in Agriculture and Aquaculture: The Engleberg Report. International Reference Center for Waste Disposal (IRCWD) News 23:11-18. JVA. 1998. Soil Classification Map, prepared by BWP, Amman. Lauchli, A and E. Epstein, 1990. Plant Responses to Saline and Sodic Conditions In: Agricultural Salinity Assessment and Management. K.K Tanji (ed.). Prepared by the Water Quality Technical Committee of the Irrigation and Drainage Division of the American Society of Civil Engineers. ASCE Manuals and Reports on Engineering Practices 71, ASCE, New York, pp 113-137. Maas, E.V 1984. Salt tolerance of plants in Christie, B. R. (ed): The handbook of plant science in agriculture, CRC Press Boca Raton, Florida. Maas, E. V. 1990. Crop Salt Tolerance. In: Agricultural Salinity Assessment and Management Manual. K. K. Tanji (ed). Prepared by the Water Quality Technical Committee of the Irrigation and Drainage Division of the American Society of Civil Engineers. ASCE Manuals and Reports on Engineering Practices 71, ASCE, New York/ pp 262-304. Maas, E. V. and G. J Hoffman,. 1977. Crop Salt Tolerance – Current Assessment, Irrigation and Drainage Division ASCE 103 (TRZ):115-134; Proceeding Paper 12933. Maas, E. V. and S. R. Grattan. 1998. Crop Yields as Affect by Salinity. In: Agricultural Drainage. ASA Monograph ___. W. Skaggs and J. van Schilfgaarde (eds). American Society of Agronomy, Madison, WI (In Press) Mara, D. and S. Cairncross. 1989. Guidelines for the Safe Use of Wastewater and Excreta in Agriculture and Aquaculture: Measures for Public Health Protection. World Health Organization, Geneva. Meier, B. 1996. Is it Possible to Manage Future Agriculture in the Jordan Valley by Utilizing Saline Water? Occident and Orient 1(2):9. MOA: Ministry of Agriculture 1993, the agricultural policy charter, Amman National Water Strategy. 1997. Jordan’s Water Strategy. Ministry of Water and Irrigation. Jordan. 27

• • • •

• • • • • • • • • • • • •

NCARTT: National Center for Agricultural Research and Technology Transfer (1993), prospects of regaining sustainable growth in the Jordanian Agriculture, Amman Pastemak, D. and Y. De Malach, 1994. Crop Irrigation with Saline Water, Handbook of Plant and Crop Stress 599-622, Marcel Dekker Inc. N.Y. Pescod, M. B. 1992. Wastewater Treatment and Use in Agriculture. FAO Irrigation and Drainage Paper #47. Food and Agricultural Organization. Rome. 125pp Pescod, M. B. and A. Arar. (eds). 1988. Treatment and Use of Sewage Effluent for Irrigation. Proceeding of the FAO Regional Seminar on the Treatment and Use of Sewage Effluent for Irrigation. Nicosia, Cyprus. 7-9 October 1985. Butterworths, London. Pettygrove, G. S. and T. Asano (eds). 1985. Irrigation with Reclaimed Municipal Wastewater- A Guidance Manual. Lewis Publishers, Chelsea, MI PRIDE: Technical Report no. 4 (1992): A water management study for Jordan, MOWI, Amman Rhoades, J. D., A. Kandiah. and A.M. Mashali. 1992. The Use of Saline Waters for Crop Production. FAO Irrigation and Drainage Paper #48. Food and Agricultural Organization. Rome 133pp RSS. 1995. Monitoring Data for King Talal Reservoir. Royal Scientific Society (RSS), Amman, Jordan. Shehevet, G. 1996. Leaching to Hold Down Salinity, International Water and Irrigation Review, 16 (2):24-26. Shuval, H. I. 1993. Investigation of Typhoid Fever and Cholera Transmission by Raw Wastewater Irrigation in Santiago, Chile. Water Science and Technology 27 (3/4): 167-174. Shuval, H. I., P. Yekutiel, and B. Fattal. 1986. An Epidemiological Model of the Potential Health Risk Associated with Various Pathogens in Wastewater Irrigation. Water Science and Technology 18(10): 191-198. Tuiemeh, A. 1998. Water Quality of the Jordan Valley. Report to the FORWARD Project of Jordan. Tuiemeh, Salameh & Rimawi. 1993. The Soils of Jordan. Ministry of Agriculture. Tuiemeh, Salameh & Rimawi. 1989. Soils and Irrigation Water in The Jordan Valley area. University of Jordan, Amman. University of California Committee of Consultants 1974: Guidelines for interpretations of water quality for irrigation. University of California, Davis, USA. USBR. 1995. Final Preliminary Assessment of King Talal Reservoir Sedimentation and Water Quality. Report to USAID and the Ministry of Water and Irrigation. Amman, Jordan. Westcot, D. W. 1997. Quality Control of Wastewater for Irrigated Crop Production. Water Report #10. Food and Agricultural Organization of the United Nations. Rome.

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•

7.

WHO. 1989. Health Guidelines for the Use of Wastewater in Agriculture and Aquaculture: Report of a WHO Scientific Group. WHO Technical Report Series 778. World Health Organization, Geneva.

ADMINISTRATIVE ASPECTS

There have been no changes in staff nor in the organization of the institutions involved in this research initiative. The project was undertaken between October 1999 and March 2000.

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