Issam daghari - Academia.edu (original) (raw)
Papers by Issam daghari
Water, Jun 3, 2020
In Tunisia, water used for irrigation is often saline, increasing the risk of salinization for so... more In Tunisia, water used for irrigation is often saline, increasing the risk of salinization for soils and crops. In this study, an experiment was conducted on a tomato crop cultivated on a silty-clay soil irrigated with three different water qualities: 0, 3.5, and 7 dS•m −1. Experimental data were then used to calibrate and validate the Hydrus-1D model, which simulates water flow and salt transfer in soils. The successfully-calibrated and validated model was then used to study the combined effects of the soil osmotic and soil matrix potentials on root water uptake. The values of the root mean square error (RMSE), the coefficient of determination (CD), the modeling efficiency (EF), and the coefficient of residual mass (CRM) were close to their optimal values for both soil water content and soil electrical conductivity profiles, indicating the reliability of the model to reproduce water and salt dynamics. Relative yields (Y r), indirectly estimated using actual and potential root water uptake (transpiration), indicated that the multiplicative stress response model (using the S-shape model) satisfactorily simulates measured yields and reproduces the effects of irrigation with saline waters on crop yields. An alternative scenario using a reduction of water requirements by 50% was investigated to assess an irrigation method with considerable water savings. As the results show that relative yields, Y r , were only slightly reduced, the crop water requirements estimated by CROPWAT 8.0 must have been overestimated. The variation of the soil salinity in the root zone highlighted a high salinization risk in the short-term when water of 7 dS•m −1 is used for irrigation.
Asian journal of agriculture, Aug 22, 2022
Environmental Science and Pollution Research, Jul 10, 2021
In Diyar-Al-Hujjej irrigated area, aquifer's over-exploitation, sea intrusion and abandonment of ... more In Diyar-Al-Hujjej irrigated area, aquifer's over-exploitation, sea intrusion and abandonment of irrigated areas and wells were took place. A yield decrease for all crops was observed. Average aquifer water electrical conductivity (EC) jumps from 4 dS/m to 6.6 dS/m between 1969 and 2017. A fresh surface water transfer over more than 100 km was launched in 1998 to safeguard this irrigated area but this fresh water supply is not stable, it varies from one year to another (about 1,900,000 m 3 in 2015 and only 60,000 m 3 in 2018) while annual cops water requirements of the perimeter is about 2,500,000 m 3. An adaptation by farmers to this new situation of saline and water stress was observed. The follow-up surveys of the farmer's practices showed that: (i) new crops with high added-value grown during the rainy season were introduced in association with dry season crops (strawberry-pepper association), (ii) rainfed crops, fallow and water blending are common practices, and (iii) growing of rainy season crops in the aim to reduce water supply. The instability of fresh surface water volume transferred constitutes the main threat for this perimeter. The use of aquifer salt water must be stopped; it is the cause of the large quantities of salts supplied (over 13,000 kg / ha) and also of the low annual net income achieved. Net revenue was less than 2,000 US /haundersaltwaterandreachedeven8,000US/ha under salt water and reached even 8,000 US /haundersaltwaterandreachedeven8,000US/ha when su cient surface water is available. An agrarian reform policy must be applied for this perimeter; only crops whose water requirements are partially met by rain should be grown. Introduction of another more sustainable water source should be initiated (as desalination) even at private farm level.
Editions universitaires europeennes eBooks, Sep 9, 2019
L'irrigation localisee est la technique d'irrigation la plus econome en eau. Elle est rec... more L'irrigation localisee est la technique d'irrigation la plus econome en eau. Elle est recommandee pour les cultures arboricoles et les cultures maraicheres mais dans l'avenir elle sera etendue aux grandes cultures. Elle se presente sous plusieurs variantes et elle constitue un moyen efficace d’apport des elements fertilisants. L'irrigation a la tasse n'est rien d'autres qu'une irrigation localisee : chaque plante ou chaque arbre recoit une tasse de 5 a 10 litres d'eau tous les jours ou tous les 2 a 3 jours. Aussi, l'irrigation a la jarre a concue pour la premiere fois Djerba en Tunisie est un autre exemple
DESALINATION AND WATER TREATMENT, 2021
Several areas are experiencing local water shortages and are now using desalination devices to mi... more Several areas are experiencing local water shortages and are now using desalination devices to mitigate its effect. In this study, an equation is proposed to estimate the production unit cost of reverse osmosis (RO) powered by a photovoltaic (PV) system based on current PV-RO module prices used to determine the economic feasibility of the system. PV-RO for agriculture in the coastal area of Dyiar-Al-Hujjej. This study area suffers from seawater intrusion and is also threatened by the salinization of the soil due to irrigation. The results show as expected that the price increases from 1.02 to 2.12 US $/m 3 for 3,000 and 9,000 ppm respectively, as the salinity of the feed water increases. For crop selection, high-value crops and crops with low water requirements are the two main criteria to consider. Strawberry is the best choice with a positive return on investment of 237%, 120%, and 60%, respectively, for 3,000, 6,000 and 9,000 ppm, unlike other crops that still have a negative return on investment. Increasing needs to meet the demand for water in agriculture harms the economy of the PV-RO system.
Irrigation and Drainage, Mar 2, 2020
In the irrigated area of Korba, aquifer high electrical conductivity exceeding 28 dS m‾¹ was meas... more In the irrigated area of Korba, aquifer high electrical conductivity exceeding 28 dS m‾¹ was measured. Increasing soil electrical conductivity has led to an abandonment of farms and a reduction of the area devoted to some crops, such as tomatoes, which fell from 450 to 210 ha, between 1998 and 2011. Some new practices such water blending, crop rotation and crop association have been introduced. The most important crop combination of strawberry-pepper is widespread throughout the area. The two crops were grown simultaneously in the same plots for two successive years during the first years of the project; this new combination reached 130 ha. During recent years, this combination has been maintained for only one year due to the observed yield decrease during the second year. In order to evaluate this crop combination and with the aim of understanding why farmers grow only one year of this combination, trials were conducted from July 2011 to August 2013. Soil electrical conductivity (EC) distribution and irrigation uniformity were analysed. During irrigation seasons, soil EC was 1.45 dS m‾¹ at the beginning (July 2011) and reached 3.3 and 5.52 dS m‾¹ respectively in August 2012 and August 2013. These soil EC values were high for strawberry. This explains why farmers choose rainfed crops, and salt-tolerant crops during the second year. A survey concerning irrigation uniformity gave an acceptable figure of almost 90%. Even if the gross margin shows that it is not worthwhile to blend fresh and saline water, farmers opt for water blending.
Water Science & Technology: Water Supply, Sep 10, 2020
Irrigation in Tunisia is threatened all over the country. The irrigated coastal area of Dyiar-Al-... more Irrigation in Tunisia is threatened all over the country. The irrigated coastal area of Dyiar-Al-Hujjej has observed a drop in agricultural activity following a seawater intrusion. Thus, yields have become disrupted in direct relation to the quantities of fresh water supplied and transferred over a distance of 100 km. For the sustainability of this area, the feasibility of using desalinated water to stabilize the irrigation water supply was analyzed. When all crop water requirements are to be met with desalinated water, the net income is negative for crops currently grown, except strawberry. All the open-field crops remain unprofitable even in the case of agro-industrial development, except tomatoes. A blending between desalinated seawater and aquifer saltwater also leads to a negative income for the main crops. The introduction of greenhouses to replace the same open-season crops is beneficial when desalinated water is used. The use of desalinated water in irrigation faces the high cost of desalination (0.
Environmental Science and Pollution Research, Jul 6, 2020
Korba is a coastal region and the main production area for strawberries, tomatoes, and peppers in... more Korba is a coastal region and the main production area for strawberries, tomatoes, and peppers in Tunisia. Due to the use of saline groundwater in irrigation, soil salinization increases in the area. Farmers are therefore forced to reduce the salinity in the soil by adopting a suitable water management strategy "blended water," with the appropriate irrigation system "drip irrigation," and new farming techniques "crop combinations and crop rotations" to achieve sustainability. Based on the electrical conductivity (EC) of the groundwater (5.05 dS/m) and freshwater (1.7 dS/m), in our pilot plot, we determine that the blended water used in irrigation must contain 28.55% of groundwater with 71.45% freshwater to have a 50%strawberry yield potential because strawberry is the most salt-sensitive crop produced in the region. The strawberry-pepper's combination is a way to improve farmers' incomes with a 200% intensification rate, taking advantage of the rains and the availability of surface water during the wet season. However, the soil salinity used to increase under these crops from 1.28 dS/m in November 2018 to 3.04 dS/m of soil EC in September 2019. This is beyond the strawberry salt tolerance threshold (1 dS/m). Even after planting summer crops, tomatoes, and peppers, the rate of evolution of soil salinity exceeds 200% (~4.5 dS/m) and 122% (~3 dS/m), respectively. Therefore, the rotation becomes necessary to reduce the soil salinity and thus prepare the soil for the next planting of tomatoes, peppers, and strawberry-pepper's combination. The introduction of rainfed crops or fallow in the agricultural rotation system helped farmers to reduce soil salinity with about 56% and 67.2% for crop rotations including summer crops and the strawberry-pepper's combination, respectively, with a return period of 1 year.
IntechOpen eBooks, Jun 1, 2022
In arid countries like Tunisia, the need to find new sources of water for irrigation has become i... more In arid countries like Tunisia, the need to find new sources of water for irrigation has become imminent. Desalination of seawater can be an alternative to irrigation. Water desalination is a process that makes it possible to obtain freshwater (drinking water or, more rarely, due to the cost, usable for irrigation) from brackish or saltwater (seawater in particular). In this article, we take a look at the leading food companies specializing in desalination of irrigation around the world and the prospects for the solar energy desalination potential for irrigation in Tunisia. We have noticed that several companies invest money to desalinate water for agricultural purposes. However, the cost of a cubic meter of water sometimes remains high to go forward with this new technology.
OAlib, 2021
The problem of water scarcity and salinity in North Africa is one of the main important constrain... more The problem of water scarcity and salinity in North Africa is one of the main important constraints to any development. Libya is considered a Saharan country more than 90% of its area. Average annual rain is about 100 mm while evapotranspiration is more than 2000 mm. The Al-Hira study area belongs to the Al Djfara plain in northwestern Libya, which is one of the most important pastoral areas of the region and it was until the 90s considered a good grazing area. The study area covers an area of approximately 269,938 hectares. The study carried out in the Al Hira area belonging to the Djfara plain showed an advanced state of degradation of natural resources: 1) decrease in irrigated areas and shrub vegetation; 2) increase in bare land areas; 3) fair water management (poor irrigation uniformity, bad irrigation scheduling). The irrigated areas were decreased from 18,000 to 12,000 ha between 1996 and 2008; an increase in bare soil was observed (23,000 ha to about 35,000 ha) between 1988 and 2009. The uniformity of localized irrigation under olive trees is often less than 50%, indicating the need to replace all the irrigation networks. In the case of sprinkler irrigation, irrigation equipment appears to meet the standards but the uniformity coefficient obtained at field level is very low (63%). The study on natural resources management in this area is imperative. Also an integrated water resources scheme is necessary for a better use of transferred saline water and aquifer fresh water.
Water Science & Technology: Water Supply, Feb 22, 2021
The project 'Research and Training on Irrigation with Saline Water in Tunisia', with the project ... more The project 'Research and Training on Irrigation with Saline Water in Tunisia', with the project report published by UNESCO in 1970, was set up to specify Tunisian standards for the use of saline water and to mitigate their effects on crop yields. The objective of this study is to assess the risk of longterm soil salinization by considering the agricultural practices mentioned in the project for the 'Water Quality' experiment in the semi-arid region of Cherfech (Tunisia). A Hydrus-1D model was used to simulate the movement of water and the transfer of salts. Soil hydraulic and solute transport parameters were estimated using inverse modeling. Calibration and validation of the model were made for the water and salt profiles carried out with four irrigation qualities QA, QB, QC and QD. Four scenarios over 50 years were studied: (i) S1 with rainfall (400 mm) only; (ii) S2 with rainfall and irrigation (1,400 mm); (iii) S3 with a 2 C increase in temperature; (iv) S4 with the addition of 100 mm•d À1 of rainfall. The four scenarios highlighted the high risk of soil salinization, especially for the QB, QC and QD qualities after 20 years of irrigation and the deep dynamics of water and salts beyond the root zone which increases the risk of groundwater salinization.
Irrigated agriculture faces serious problems of soil salinization in the arid and semi-arid regio... more Irrigated agriculture faces serious problems of soil salinization in the arid and semi-arid regions of the world. Tunisian saline soils occupy about 25% of the total irrigated area. In this study, the irrigated area of "Diyar El Hujjaj" in Tunisia was considered when sea water intrusion and a salinisation of the aquifer were observed. As a result, many pumping wells and farms have been abandoned. An expensive surface fresh water transfer from more than 100 Km was done and a mixture between aquifer salty water and surface water is common practice. In this paper, SaltMod model was used to simulate and analyze the soil salinity evolution under several water management scenarios. The first one was a new practice (simultaneously growth of strawberry and pepper). The others concerned the soil salinity evolution under crops rotation compounded by irrigated high value crops, fallow and rainfed crops using an alternative water supply options: groundwater, surface water and a mixture of surface water and groundwater. Results show that in using only groundwater, simulated soil salinity reaches its peak of about 12 dS m-1 when average salinity as high as 9 dS m-1 was recorded, and then decreases significantly to a level of 2 dS/m when surface water is applied. However these conditions are not usually met in the study area conditions as the crop water requirement is fairly difficult to be satisfied by surface water irrigation. The new farming practices option using mixture of surface and groundwater could be sufficient to keep soil within an acceptable range of salinity level of about 2.5 dS/m and 5 dS/m during the first and the second year respectively. Under the case study conditions, using the mixture of groundwater and surface water could be a viable alternative for irrigation with an agriculture practices including crops rotation, fallow and/or rainfed crops. Thus, to assure the agricultural success in areas at high risk of salinity, it appears indispensable to control the economical factors relating to the interaction between land attribution and irrigated area management and study the feasibility of the water desalination for agriculture particularly for crops of high added value.
International journal of advanced research, Jul 31, 2016
The wetted volume of root area is one of the most important parameters for irrigation efficiency ... more The wetted volume of root area is one of the most important parameters for irrigation efficiency in the drip irrigation. Three durations (shortmoderatelong duration) were compared with supplied 40, 60 and 80 L respectively. Three discharges (8, 16, and 32 l/h) were used and four treatments were tested for each discharge: one dripper, two drippers, four drippers with a looping of 20 cm and 40 cm around the trunk. The case of discharge 8 L/h with irrigation duration (10 h) in the treatment four drippers with a looping 40 cm around the trunk was superior and given the best percentage of root wetted area, 100% of the effective root area, as well as, an average volumetric water content and a coefficient of uniformity were 26% and 87%, respectively. Also, the saved water was 65.5 % compared to surface irrigation.
Journal of New Sciences, 2020
Asian journal of agriculture, Aug 22, 2022
Journal of New Sciences, 2017
Pathways and Challenges for Efficient Desalination
In arid countries like Tunisia, the need to find new sources of water for irrigation has become i... more In arid countries like Tunisia, the need to find new sources of water for irrigation has become imminent. Desalination of seawater can be an alternative to irrigation. Water desalination is a process that makes it possible to obtain freshwater (drinking water or, more rarely, due to the cost, usable for irrigation) from brackish or saltwater (seawater in particular). In this article, we take a look at the leading food companies specializing in desalination of irrigation around the world and the prospects for the solar energy desalination potential for irrigation in Tunisia. We have noticed that several companies invest money to desalinate water for agricultural purposes. However, the cost of a cubic meter of water sometimes remains high to go forward with this new technology.
International Journal of Advanced Research, 2016
The wetted volume of root area is one of the most important parameters for irrigation efficiency ... more The wetted volume of root area is one of the most important parameters for irrigation efficiency in the drip irrigation. Three durations (shortmoderatelong duration) were compared with supplied 40, 60 and 80 L respectively. Three discharges (8, 16, and 32 l/h) were used and four treatments were tested for each discharge: one dripper, two drippers, four drippers with a looping of 20 cm and 40 cm around the trunk. The case of discharge 8 L/h with irrigation duration (10 h) in the treatment four drippers with a looping 40 cm around the trunk was superior and given the best percentage of root wetted area, 100% of the effective root area, as well as, an average volumetric water content and a coefficient of uniformity were 26% and 87%, respectively. Also, the saved water was 65.5 % compared to surface irrigation.
Water, Jun 3, 2020
In Tunisia, water used for irrigation is often saline, increasing the risk of salinization for so... more In Tunisia, water used for irrigation is often saline, increasing the risk of salinization for soils and crops. In this study, an experiment was conducted on a tomato crop cultivated on a silty-clay soil irrigated with three different water qualities: 0, 3.5, and 7 dS•m −1. Experimental data were then used to calibrate and validate the Hydrus-1D model, which simulates water flow and salt transfer in soils. The successfully-calibrated and validated model was then used to study the combined effects of the soil osmotic and soil matrix potentials on root water uptake. The values of the root mean square error (RMSE), the coefficient of determination (CD), the modeling efficiency (EF), and the coefficient of residual mass (CRM) were close to their optimal values for both soil water content and soil electrical conductivity profiles, indicating the reliability of the model to reproduce water and salt dynamics. Relative yields (Y r), indirectly estimated using actual and potential root water uptake (transpiration), indicated that the multiplicative stress response model (using the S-shape model) satisfactorily simulates measured yields and reproduces the effects of irrigation with saline waters on crop yields. An alternative scenario using a reduction of water requirements by 50% was investigated to assess an irrigation method with considerable water savings. As the results show that relative yields, Y r , were only slightly reduced, the crop water requirements estimated by CROPWAT 8.0 must have been overestimated. The variation of the soil salinity in the root zone highlighted a high salinization risk in the short-term when water of 7 dS•m −1 is used for irrigation.
Asian journal of agriculture, Aug 22, 2022
Environmental Science and Pollution Research, Jul 10, 2021
In Diyar-Al-Hujjej irrigated area, aquifer's over-exploitation, sea intrusion and abandonment of ... more In Diyar-Al-Hujjej irrigated area, aquifer's over-exploitation, sea intrusion and abandonment of irrigated areas and wells were took place. A yield decrease for all crops was observed. Average aquifer water electrical conductivity (EC) jumps from 4 dS/m to 6.6 dS/m between 1969 and 2017. A fresh surface water transfer over more than 100 km was launched in 1998 to safeguard this irrigated area but this fresh water supply is not stable, it varies from one year to another (about 1,900,000 m 3 in 2015 and only 60,000 m 3 in 2018) while annual cops water requirements of the perimeter is about 2,500,000 m 3. An adaptation by farmers to this new situation of saline and water stress was observed. The follow-up surveys of the farmer's practices showed that: (i) new crops with high added-value grown during the rainy season were introduced in association with dry season crops (strawberry-pepper association), (ii) rainfed crops, fallow and water blending are common practices, and (iii) growing of rainy season crops in the aim to reduce water supply. The instability of fresh surface water volume transferred constitutes the main threat for this perimeter. The use of aquifer salt water must be stopped; it is the cause of the large quantities of salts supplied (over 13,000 kg / ha) and also of the low annual net income achieved. Net revenue was less than 2,000 US /haundersaltwaterandreachedeven8,000US/ha under salt water and reached even 8,000 US /haundersaltwaterandreachedeven8,000US/ha when su cient surface water is available. An agrarian reform policy must be applied for this perimeter; only crops whose water requirements are partially met by rain should be grown. Introduction of another more sustainable water source should be initiated (as desalination) even at private farm level.
Editions universitaires europeennes eBooks, Sep 9, 2019
L'irrigation localisee est la technique d'irrigation la plus econome en eau. Elle est rec... more L'irrigation localisee est la technique d'irrigation la plus econome en eau. Elle est recommandee pour les cultures arboricoles et les cultures maraicheres mais dans l'avenir elle sera etendue aux grandes cultures. Elle se presente sous plusieurs variantes et elle constitue un moyen efficace d’apport des elements fertilisants. L'irrigation a la tasse n'est rien d'autres qu'une irrigation localisee : chaque plante ou chaque arbre recoit une tasse de 5 a 10 litres d'eau tous les jours ou tous les 2 a 3 jours. Aussi, l'irrigation a la jarre a concue pour la premiere fois Djerba en Tunisie est un autre exemple
DESALINATION AND WATER TREATMENT, 2021
Several areas are experiencing local water shortages and are now using desalination devices to mi... more Several areas are experiencing local water shortages and are now using desalination devices to mitigate its effect. In this study, an equation is proposed to estimate the production unit cost of reverse osmosis (RO) powered by a photovoltaic (PV) system based on current PV-RO module prices used to determine the economic feasibility of the system. PV-RO for agriculture in the coastal area of Dyiar-Al-Hujjej. This study area suffers from seawater intrusion and is also threatened by the salinization of the soil due to irrigation. The results show as expected that the price increases from 1.02 to 2.12 US $/m 3 for 3,000 and 9,000 ppm respectively, as the salinity of the feed water increases. For crop selection, high-value crops and crops with low water requirements are the two main criteria to consider. Strawberry is the best choice with a positive return on investment of 237%, 120%, and 60%, respectively, for 3,000, 6,000 and 9,000 ppm, unlike other crops that still have a negative return on investment. Increasing needs to meet the demand for water in agriculture harms the economy of the PV-RO system.
Irrigation and Drainage, Mar 2, 2020
In the irrigated area of Korba, aquifer high electrical conductivity exceeding 28 dS m‾¹ was meas... more In the irrigated area of Korba, aquifer high electrical conductivity exceeding 28 dS m‾¹ was measured. Increasing soil electrical conductivity has led to an abandonment of farms and a reduction of the area devoted to some crops, such as tomatoes, which fell from 450 to 210 ha, between 1998 and 2011. Some new practices such water blending, crop rotation and crop association have been introduced. The most important crop combination of strawberry-pepper is widespread throughout the area. The two crops were grown simultaneously in the same plots for two successive years during the first years of the project; this new combination reached 130 ha. During recent years, this combination has been maintained for only one year due to the observed yield decrease during the second year. In order to evaluate this crop combination and with the aim of understanding why farmers grow only one year of this combination, trials were conducted from July 2011 to August 2013. Soil electrical conductivity (EC) distribution and irrigation uniformity were analysed. During irrigation seasons, soil EC was 1.45 dS m‾¹ at the beginning (July 2011) and reached 3.3 and 5.52 dS m‾¹ respectively in August 2012 and August 2013. These soil EC values were high for strawberry. This explains why farmers choose rainfed crops, and salt-tolerant crops during the second year. A survey concerning irrigation uniformity gave an acceptable figure of almost 90%. Even if the gross margin shows that it is not worthwhile to blend fresh and saline water, farmers opt for water blending.
Water Science & Technology: Water Supply, Sep 10, 2020
Irrigation in Tunisia is threatened all over the country. The irrigated coastal area of Dyiar-Al-... more Irrigation in Tunisia is threatened all over the country. The irrigated coastal area of Dyiar-Al-Hujjej has observed a drop in agricultural activity following a seawater intrusion. Thus, yields have become disrupted in direct relation to the quantities of fresh water supplied and transferred over a distance of 100 km. For the sustainability of this area, the feasibility of using desalinated water to stabilize the irrigation water supply was analyzed. When all crop water requirements are to be met with desalinated water, the net income is negative for crops currently grown, except strawberry. All the open-field crops remain unprofitable even in the case of agro-industrial development, except tomatoes. A blending between desalinated seawater and aquifer saltwater also leads to a negative income for the main crops. The introduction of greenhouses to replace the same open-season crops is beneficial when desalinated water is used. The use of desalinated water in irrigation faces the high cost of desalination (0.
Environmental Science and Pollution Research, Jul 6, 2020
Korba is a coastal region and the main production area for strawberries, tomatoes, and peppers in... more Korba is a coastal region and the main production area for strawberries, tomatoes, and peppers in Tunisia. Due to the use of saline groundwater in irrigation, soil salinization increases in the area. Farmers are therefore forced to reduce the salinity in the soil by adopting a suitable water management strategy "blended water," with the appropriate irrigation system "drip irrigation," and new farming techniques "crop combinations and crop rotations" to achieve sustainability. Based on the electrical conductivity (EC) of the groundwater (5.05 dS/m) and freshwater (1.7 dS/m), in our pilot plot, we determine that the blended water used in irrigation must contain 28.55% of groundwater with 71.45% freshwater to have a 50%strawberry yield potential because strawberry is the most salt-sensitive crop produced in the region. The strawberry-pepper's combination is a way to improve farmers' incomes with a 200% intensification rate, taking advantage of the rains and the availability of surface water during the wet season. However, the soil salinity used to increase under these crops from 1.28 dS/m in November 2018 to 3.04 dS/m of soil EC in September 2019. This is beyond the strawberry salt tolerance threshold (1 dS/m). Even after planting summer crops, tomatoes, and peppers, the rate of evolution of soil salinity exceeds 200% (~4.5 dS/m) and 122% (~3 dS/m), respectively. Therefore, the rotation becomes necessary to reduce the soil salinity and thus prepare the soil for the next planting of tomatoes, peppers, and strawberry-pepper's combination. The introduction of rainfed crops or fallow in the agricultural rotation system helped farmers to reduce soil salinity with about 56% and 67.2% for crop rotations including summer crops and the strawberry-pepper's combination, respectively, with a return period of 1 year.
IntechOpen eBooks, Jun 1, 2022
In arid countries like Tunisia, the need to find new sources of water for irrigation has become i... more In arid countries like Tunisia, the need to find new sources of water for irrigation has become imminent. Desalination of seawater can be an alternative to irrigation. Water desalination is a process that makes it possible to obtain freshwater (drinking water or, more rarely, due to the cost, usable for irrigation) from brackish or saltwater (seawater in particular). In this article, we take a look at the leading food companies specializing in desalination of irrigation around the world and the prospects for the solar energy desalination potential for irrigation in Tunisia. We have noticed that several companies invest money to desalinate water for agricultural purposes. However, the cost of a cubic meter of water sometimes remains high to go forward with this new technology.
OAlib, 2021
The problem of water scarcity and salinity in North Africa is one of the main important constrain... more The problem of water scarcity and salinity in North Africa is one of the main important constraints to any development. Libya is considered a Saharan country more than 90% of its area. Average annual rain is about 100 mm while evapotranspiration is more than 2000 mm. The Al-Hira study area belongs to the Al Djfara plain in northwestern Libya, which is one of the most important pastoral areas of the region and it was until the 90s considered a good grazing area. The study area covers an area of approximately 269,938 hectares. The study carried out in the Al Hira area belonging to the Djfara plain showed an advanced state of degradation of natural resources: 1) decrease in irrigated areas and shrub vegetation; 2) increase in bare land areas; 3) fair water management (poor irrigation uniformity, bad irrigation scheduling). The irrigated areas were decreased from 18,000 to 12,000 ha between 1996 and 2008; an increase in bare soil was observed (23,000 ha to about 35,000 ha) between 1988 and 2009. The uniformity of localized irrigation under olive trees is often less than 50%, indicating the need to replace all the irrigation networks. In the case of sprinkler irrigation, irrigation equipment appears to meet the standards but the uniformity coefficient obtained at field level is very low (63%). The study on natural resources management in this area is imperative. Also an integrated water resources scheme is necessary for a better use of transferred saline water and aquifer fresh water.
Water Science & Technology: Water Supply, Feb 22, 2021
The project 'Research and Training on Irrigation with Saline Water in Tunisia', with the project ... more The project 'Research and Training on Irrigation with Saline Water in Tunisia', with the project report published by UNESCO in 1970, was set up to specify Tunisian standards for the use of saline water and to mitigate their effects on crop yields. The objective of this study is to assess the risk of longterm soil salinization by considering the agricultural practices mentioned in the project for the 'Water Quality' experiment in the semi-arid region of Cherfech (Tunisia). A Hydrus-1D model was used to simulate the movement of water and the transfer of salts. Soil hydraulic and solute transport parameters were estimated using inverse modeling. Calibration and validation of the model were made for the water and salt profiles carried out with four irrigation qualities QA, QB, QC and QD. Four scenarios over 50 years were studied: (i) S1 with rainfall (400 mm) only; (ii) S2 with rainfall and irrigation (1,400 mm); (iii) S3 with a 2 C increase in temperature; (iv) S4 with the addition of 100 mm•d À1 of rainfall. The four scenarios highlighted the high risk of soil salinization, especially for the QB, QC and QD qualities after 20 years of irrigation and the deep dynamics of water and salts beyond the root zone which increases the risk of groundwater salinization.
Irrigated agriculture faces serious problems of soil salinization in the arid and semi-arid regio... more Irrigated agriculture faces serious problems of soil salinization in the arid and semi-arid regions of the world. Tunisian saline soils occupy about 25% of the total irrigated area. In this study, the irrigated area of "Diyar El Hujjaj" in Tunisia was considered when sea water intrusion and a salinisation of the aquifer were observed. As a result, many pumping wells and farms have been abandoned. An expensive surface fresh water transfer from more than 100 Km was done and a mixture between aquifer salty water and surface water is common practice. In this paper, SaltMod model was used to simulate and analyze the soil salinity evolution under several water management scenarios. The first one was a new practice (simultaneously growth of strawberry and pepper). The others concerned the soil salinity evolution under crops rotation compounded by irrigated high value crops, fallow and rainfed crops using an alternative water supply options: groundwater, surface water and a mixture of surface water and groundwater. Results show that in using only groundwater, simulated soil salinity reaches its peak of about 12 dS m-1 when average salinity as high as 9 dS m-1 was recorded, and then decreases significantly to a level of 2 dS/m when surface water is applied. However these conditions are not usually met in the study area conditions as the crop water requirement is fairly difficult to be satisfied by surface water irrigation. The new farming practices option using mixture of surface and groundwater could be sufficient to keep soil within an acceptable range of salinity level of about 2.5 dS/m and 5 dS/m during the first and the second year respectively. Under the case study conditions, using the mixture of groundwater and surface water could be a viable alternative for irrigation with an agriculture practices including crops rotation, fallow and/or rainfed crops. Thus, to assure the agricultural success in areas at high risk of salinity, it appears indispensable to control the economical factors relating to the interaction between land attribution and irrigated area management and study the feasibility of the water desalination for agriculture particularly for crops of high added value.
International journal of advanced research, Jul 31, 2016
The wetted volume of root area is one of the most important parameters for irrigation efficiency ... more The wetted volume of root area is one of the most important parameters for irrigation efficiency in the drip irrigation. Three durations (shortmoderatelong duration) were compared with supplied 40, 60 and 80 L respectively. Three discharges (8, 16, and 32 l/h) were used and four treatments were tested for each discharge: one dripper, two drippers, four drippers with a looping of 20 cm and 40 cm around the trunk. The case of discharge 8 L/h with irrigation duration (10 h) in the treatment four drippers with a looping 40 cm around the trunk was superior and given the best percentage of root wetted area, 100% of the effective root area, as well as, an average volumetric water content and a coefficient of uniformity were 26% and 87%, respectively. Also, the saved water was 65.5 % compared to surface irrigation.
Journal of New Sciences, 2020
Asian journal of agriculture, Aug 22, 2022
Journal of New Sciences, 2017
Pathways and Challenges for Efficient Desalination
In arid countries like Tunisia, the need to find new sources of water for irrigation has become i... more In arid countries like Tunisia, the need to find new sources of water for irrigation has become imminent. Desalination of seawater can be an alternative to irrigation. Water desalination is a process that makes it possible to obtain freshwater (drinking water or, more rarely, due to the cost, usable for irrigation) from brackish or saltwater (seawater in particular). In this article, we take a look at the leading food companies specializing in desalination of irrigation around the world and the prospects for the solar energy desalination potential for irrigation in Tunisia. We have noticed that several companies invest money to desalinate water for agricultural purposes. However, the cost of a cubic meter of water sometimes remains high to go forward with this new technology.
International Journal of Advanced Research, 2016
The wetted volume of root area is one of the most important parameters for irrigation efficiency ... more The wetted volume of root area is one of the most important parameters for irrigation efficiency in the drip irrigation. Three durations (shortmoderatelong duration) were compared with supplied 40, 60 and 80 L respectively. Three discharges (8, 16, and 32 l/h) were used and four treatments were tested for each discharge: one dripper, two drippers, four drippers with a looping of 20 cm and 40 cm around the trunk. The case of discharge 8 L/h with irrigation duration (10 h) in the treatment four drippers with a looping 40 cm around the trunk was superior and given the best percentage of root wetted area, 100% of the effective root area, as well as, an average volumetric water content and a coefficient of uniformity were 26% and 87%, respectively. Also, the saved water was 65.5 % compared to surface irrigation.