The objective of this paper is to identify the influencing factors of farmers' willingness for ea... more The objective of this paper is to identify the influencing factors of farmers' willingness for early adoption of enhanced irrigation technologies in Tunisia. We estimate a multinomial logit model with data from 931 farmers in Central (Chebika) and Northern (Fernana) of Tunisia. Regression results reveal that early adoption is positively influenced by levels of extension service quality, trust in farmers' associations and extension agents, farmer's perception towards the innovation, credit access, and off-farm income. However, it is negatively affected by market access issues, risk aversion, and age. Risk, trust, and perception towards technology are important factors in driving early adoption decision. The findings imply that farmers training on water conservation technologies, financial support for innovation adoption, awareness of young farmers about the opportunities of agricultural innovation, incentives to farmers' associations in order to improve their market access, and inclusive participatory approaches during technology generation and transfer are all accelerators of early adoption of innovations by farmers.
Around 27% of aquifers in Tunisia are being overexploited. Groundwater extractions is mainly for ... more Around 27% of aquifers in Tunisia are being overexploited. Groundwater extractions is mainly for the irrigation sector, where more than 40% of the water used for irrigation comes from GW sources. The objective of this study is to critically review and analyze GW management instruments adopted in Tunisia during the last four decades. Evaluation of current instruments was based on a set of criteria (the impact of the instrument on increasing water productivity, reducing aquifer withdrawals, acceptability of the instrument and its implementation cost) assessed through interviews with policy makers and experts, in addition to discussions at farmers' focus groups. Results show that regulatory instruments are widely used but weakly enforced, which can explain their limited impact. To be more effective, economic instruments need a better vertical interplay between different stakeholders. Analysis of stakeholders' participation shows limited awareness by farmers and a lack of collective actions for GW management at local levels. The alignment of GW policies to other cross-sectorial policies, the enhancement of the vertical interplay between water users' associations and local and national water administrations, and the horizontal integration of different water users and managers at the local and regional levels, are among the main recommendations of this study.
African Journal of Agricultural and Resource Economics, 2011
ABSTRACT This article analyzes the potential impact of climate change on cereal productivity in t... more ABSTRACT This article analyzes the potential impact of climate change on cereal productivity in the Béja region of northwestern Tunisia. Multiple regression models were estimated for the cereal crops durum wheat, bread wheat and barley, using annual data from 1980 to 2009. The yield of each crop was used as the dependent variable, while the explanatory variables were mainly related to the climate (precipitation and temperature) and technological progress. The results show that yield variability is affected by climate and technological progress variables. The projected climate change scenarios predicted by the HadCM3 model will have a significant effect on crop yields by 2030, particularly for bread wheat. Some adaptation strategies that could alleviate climate change effects on cereal crops yields in the long run are the identification of new agricultural practices in this area, the widespread diffusion of varieties that can tolerate rainfall shortage during the critical periods, and the adoption of early maturing varieties.
Zenodo (CERN European Organization for Nuclear Research), May 22, 2023
Déclaration de divulgation : L'auteur n'a pas connaissance de quelconque financement qui pourrait... more Déclaration de divulgation : L'auteur n'a pas connaissance de quelconque financement qui pourrait affecter l'objectivité de cette étude. Conflit d'intérêts : L'auteur ne signale aucun conflit d'intérêts. Pour citer cet article : LEGHRISSI. H, CHEBIL .A, MELLAH .T, FRIJA .A (2023) « Optimisation de l'efficacité de l'utilisation de l'eau dans la Tunisie aride : une évaluation économique des périmètres publics irrigués pour le développement agricole »,
Better management of production factors, particularly water and nitrogen utilizations, is likely ... more Better management of production factors, particularly water and nitrogen utilizations, is likely to improve economic returns of cereal crops in Mediterranean countries. In the framework of the WatNitMED project, Tunisia was chosen as pilot study case where a new nitrogen management technique is tested. The main objective of this work is to compare physical and economic returns obtained using the recommended nitrogen strategy against those obtained using conventional farmers practices. During 2006-2007, a sample of 31 cereal growers was selected for the purpose of testing the nitrogen package recommended by WatNitMED partners. Statistical results show that grain yields are not significantly different at 5%. However, average straw yields obtained using the recommended strategy is significantly higher than in the conventional case. Moreover, the average gross margin difference between the two management practices is statistically significant at 5%. Hence, the recommended strategy is likely to increase the farmers' profits. Gross margins obtained using the new nitrogen management package are higher by 26% and 32% in the case of irrigated and rainfed areas respectively. Consequently, these results provide a basis for recommending the adoption of the proposed nitrogen technology.
Literature is scanty on how public agricultural investments can help reducing the impact of futur... more Literature is scanty on how public agricultural investments can help reducing the impact of future challenges such as climate change and population pressure on national economies. The objective of this study is to assess the medium and long-term effects of alternative agricultural research and development investment scenarios on male and female employment in 14 African countries. We first estimate the effects of agricultural investment scenarios on the overall GDP growth of a given country using partial and general equilibrium models. Secondly, using employment elasticities to GDP growth, we estimate the impact of GDP growth on overall employment in the economy. Results show that, increased investments in agriculture could generate higher overall employment and reduce gender disparities in labor participation. In 8 out of 14 sampled countries, female employment increased more than male employment in response to agricultural investments. Investment in infrastructure had higher impact on female employment growth compared to productivity scenarios.
El objetivo principal de esta tesis es analizar la competitividad del sector exportador horticola... more El objetivo principal de esta tesis es analizar la competitividad del sector exportador horticola espanol. La metodologia seguida consiste en la utilizacion de distintos enfoques analiticos con el fin de analizar la competitividad sectorial, tanto a nivel macro como microeconomico. Entre dichos metodos destacan los siguientes: -El Metodo de Box-Jenkins para el tratamiento cronologico de la exportaciones horticolas espanolas a los principales mercados. -El modelo de Porter para analizar los determinantes de la ventaja competitiva del sector horticola. -Competitividad-Precios(tipo de cambio efectivo real) -Competitividad estructural mediante el uso de algunos indicadores como el coeficiente de especializacion y dependencia, cuotas de exportacion e importacion, el indice de la ventaja comparativa revelada y el indice de comercio intraindustrial. -Un analisis econometrico de la funcion de exportacion, utilizando la metodologia de cointegracion. -En el analisis de datos de seccion cruzada, se han utilizado metodos estadisticos clasicos para analizar una encuesta a las empresas exportadoras horticolas y un modelo multinomial ordenado principalmente para determinar los factores determinantes de la competitividad empresarial. Finalmente, los resultados del trabajo indican, en general, una deterioracion de la competitividad del sector horticola especialmente durante los primeros anos de la adhesion de Espana a la U.E. La competitividad de las empresas exportadoras esta influenciada por la region, tamano, nivel tecnologico, organizacion comercial y diferenciacion del producto.
The aim of this paper is to estimate the water use efficiency of wheat farms in irrigated areas i... more The aim of this paper is to estimate the water use efficiency of wheat farms in irrigated areas in Chbika (Central Tunisia). Both Stochastic Frontier and Data Envelopment Analysis approaches were used for this purpose. Data were collected from 170 wheat farms during 2010-2011cropping season. The empirical results show that the average water use efficiency measured using the Data Envelopment Analysis (DEA) method was around 41% under constant returns to scale and 43% under variable returns to scale while it was 47% when calculated by the Stochastic Frontier Approach (SFA). This suggests that there is substantial scope for improving irrigation water use efficiency in the study region using the existing technology on wheat farms. Spearman's rank correlation coefficient between both methods in measuring irrigation water use efficiency, for our sample of wheat farms it is positive and significant at the 1% level. However, the average technical efficiencies obtained from the Stochastic Frontier method are higher than the ones estimated from Data Envelopment Analysis. This comparison shows that further empirical researches on sub-vectors efficiency calculation approaches are needed in order to obtain more accurate results than these estimations.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
This study employs stochastic data envelopment analysis (SDEA) approach for irrigation water effi... more This study employs stochastic data envelopment analysis (SDEA) approach for irrigation water efficiency measuring of wheat farms in an irrigated area of Chbika (Central Tunisia). Data was collected from 170 wheat farms during 2010-2011 cropping season. The empirical results show that the average water use efficiency for durum wheat irrigation, calculated using this approach was only around 41% under constant returns to scale (CRS) assumption; while it was 44% under variable returns to scale (VRS) assumption. This suggests that there is substantial scope for improving irrigation water use efficiency of wheat in the study region, using the existing technology on wheat farms. A Tobit regression was used to identify the determinants of the irrigation water use efficiency in the studied sample. Results of the Tobit analysis show a positive effect of wheat variety, irrigation source, membership in water users associations, irrigation scheduling and experience, on water use efficiency. These results are valuable for policy makers since they can be easily integrated in the national guidelines of irrigation water strategy.
More than 40% of irrigation water currently used in Tunisia is provided by groundwater aquifers, ... more More than 40% of irrigation water currently used in Tunisia is provided by groundwater aquifers, most of which are in a critical state of depletion due to its overexploitation during the last three decades. This paper provides a critical assessment of groundwater management in Tunisia based on interviews with key officials from central and regional administrations, in addition to farmers' questionnaires regarding attitudes and perceptions about different groundwater management instruments. Even though there is a consistent official groundwater management strategy in Tunisia, its enforcement is still problematic. Many regulatory and incentive instruments were adopted to manage groundwater but their effect was limited, partly due to the weak implementation capacities of the regional and local water administrations. Moreover, most farmers are not aware about the critical situation of this common pool resource and self-regulation initiatives are almost absent. From this assessment, we mainly conclude that the remaining activities for enhancing groundwater governance in Tunisia needs to rely on two main axes. The first is related to the improvement of administrative performances, particularly those for horizontal coordination of groundwater. The second is about investing in enhancing social capital supporting institutional changes; which is particularly necessary for the promotion of self-regulation initiatives.
This study is targeted to improve surface irrigation performance of durum wheat in swelling soils... more This study is targeted to improve surface irrigation performance of durum wheat in swelling soils. For this purpose, furrow and border irrigation trials were carried out and evaluated under different soil water depletion rates, furrow spacing and unitary inlet discharges. Irrigation was triggered whenever the soil water depletion rate reached a predetermined threshold. A comprehensive irrigation evaluation produced hydraulic, agronomic and economic indicators, such as application efficiency, distribution uniformity, crop yield, gross margin and water productivity. Experimental results showed that supplied water depths exceeded soil water deficits, inducing relevant vertical and lateral water losses. Although border and furrow irrigation crop yields were virtually tantamount (about 5.5 Mg/ha), furrow irrigation was the system of choice. An irrigation strategy based on a furrow spacing of 150 cm, an inlet discharge of 2 l/s/furrow and a soil water depletion rate of 30% required a gross water depth of 4300 m 3 /ha/yr and generated an optimum crop yield of 58 qx/ha. In the analyzed range of soil water depletion, the gross margin and water value amounted to 1064-1390 Tunisian Dinar per hectare (TD/ha) and 0.39-0.44 TD/m 3 , respectively, for a furrow spacing of 150 cm.
The objective of this paper is to identify the influencing factors of farmers' willingness for ea... more The objective of this paper is to identify the influencing factors of farmers' willingness for early adoption of enhanced irrigation technologies in Tunisia. We estimate a multinomial logit model with data from 931 farmers in Central (Chebika) and Northern (Fernana) of Tunisia. Regression results reveal that early adoption is positively influenced by levels of extension service quality, trust in farmers' associations and extension agents, farmer's perception towards the innovation, credit access, and off-farm income. However, it is negatively affected by market access issues, risk aversion, and age. Risk, trust, and perception towards technology are important factors in driving early adoption decision. The findings imply that farmers training on water conservation technologies, financial support for innovation adoption, awareness of young farmers about the opportunities of agricultural innovation, incentives to farmers' associations in order to improve their market access, and inclusive participatory approaches during technology generation and transfer are all accelerators of early adoption of innovations by farmers.
Around 27% of aquifers in Tunisia are being overexploited. Groundwater extractions is mainly for ... more Around 27% of aquifers in Tunisia are being overexploited. Groundwater extractions is mainly for the irrigation sector, where more than 40% of the water used for irrigation comes from GW sources. The objective of this study is to critically review and analyze GW management instruments adopted in Tunisia during the last four decades. Evaluation of current instruments was based on a set of criteria (the impact of the instrument on increasing water productivity, reducing aquifer withdrawals, acceptability of the instrument and its implementation cost) assessed through interviews with policy makers and experts, in addition to discussions at farmers' focus groups. Results show that regulatory instruments are widely used but weakly enforced, which can explain their limited impact. To be more effective, economic instruments need a better vertical interplay between different stakeholders. Analysis of stakeholders' participation shows limited awareness by farmers and a lack of collective actions for GW management at local levels. The alignment of GW policies to other cross-sectorial policies, the enhancement of the vertical interplay between water users' associations and local and national water administrations, and the horizontal integration of different water users and managers at the local and regional levels, are among the main recommendations of this study.
African Journal of Agricultural and Resource Economics, 2011
ABSTRACT This article analyzes the potential impact of climate change on cereal productivity in t... more ABSTRACT This article analyzes the potential impact of climate change on cereal productivity in the Béja region of northwestern Tunisia. Multiple regression models were estimated for the cereal crops durum wheat, bread wheat and barley, using annual data from 1980 to 2009. The yield of each crop was used as the dependent variable, while the explanatory variables were mainly related to the climate (precipitation and temperature) and technological progress. The results show that yield variability is affected by climate and technological progress variables. The projected climate change scenarios predicted by the HadCM3 model will have a significant effect on crop yields by 2030, particularly for bread wheat. Some adaptation strategies that could alleviate climate change effects on cereal crops yields in the long run are the identification of new agricultural practices in this area, the widespread diffusion of varieties that can tolerate rainfall shortage during the critical periods, and the adoption of early maturing varieties.
Zenodo (CERN European Organization for Nuclear Research), May 22, 2023
Déclaration de divulgation : L'auteur n'a pas connaissance de quelconque financement qui pourrait... more Déclaration de divulgation : L'auteur n'a pas connaissance de quelconque financement qui pourrait affecter l'objectivité de cette étude. Conflit d'intérêts : L'auteur ne signale aucun conflit d'intérêts. Pour citer cet article : LEGHRISSI. H, CHEBIL .A, MELLAH .T, FRIJA .A (2023) « Optimisation de l'efficacité de l'utilisation de l'eau dans la Tunisie aride : une évaluation économique des périmètres publics irrigués pour le développement agricole »,
Better management of production factors, particularly water and nitrogen utilizations, is likely ... more Better management of production factors, particularly water and nitrogen utilizations, is likely to improve economic returns of cereal crops in Mediterranean countries. In the framework of the WatNitMED project, Tunisia was chosen as pilot study case where a new nitrogen management technique is tested. The main objective of this work is to compare physical and economic returns obtained using the recommended nitrogen strategy against those obtained using conventional farmers practices. During 2006-2007, a sample of 31 cereal growers was selected for the purpose of testing the nitrogen package recommended by WatNitMED partners. Statistical results show that grain yields are not significantly different at 5%. However, average straw yields obtained using the recommended strategy is significantly higher than in the conventional case. Moreover, the average gross margin difference between the two management practices is statistically significant at 5%. Hence, the recommended strategy is likely to increase the farmers' profits. Gross margins obtained using the new nitrogen management package are higher by 26% and 32% in the case of irrigated and rainfed areas respectively. Consequently, these results provide a basis for recommending the adoption of the proposed nitrogen technology.
Literature is scanty on how public agricultural investments can help reducing the impact of futur... more Literature is scanty on how public agricultural investments can help reducing the impact of future challenges such as climate change and population pressure on national economies. The objective of this study is to assess the medium and long-term effects of alternative agricultural research and development investment scenarios on male and female employment in 14 African countries. We first estimate the effects of agricultural investment scenarios on the overall GDP growth of a given country using partial and general equilibrium models. Secondly, using employment elasticities to GDP growth, we estimate the impact of GDP growth on overall employment in the economy. Results show that, increased investments in agriculture could generate higher overall employment and reduce gender disparities in labor participation. In 8 out of 14 sampled countries, female employment increased more than male employment in response to agricultural investments. Investment in infrastructure had higher impact on female employment growth compared to productivity scenarios.
El objetivo principal de esta tesis es analizar la competitividad del sector exportador horticola... more El objetivo principal de esta tesis es analizar la competitividad del sector exportador horticola espanol. La metodologia seguida consiste en la utilizacion de distintos enfoques analiticos con el fin de analizar la competitividad sectorial, tanto a nivel macro como microeconomico. Entre dichos metodos destacan los siguientes: -El Metodo de Box-Jenkins para el tratamiento cronologico de la exportaciones horticolas espanolas a los principales mercados. -El modelo de Porter para analizar los determinantes de la ventaja competitiva del sector horticola. -Competitividad-Precios(tipo de cambio efectivo real) -Competitividad estructural mediante el uso de algunos indicadores como el coeficiente de especializacion y dependencia, cuotas de exportacion e importacion, el indice de la ventaja comparativa revelada y el indice de comercio intraindustrial. -Un analisis econometrico de la funcion de exportacion, utilizando la metodologia de cointegracion. -En el analisis de datos de seccion cruzada, se han utilizado metodos estadisticos clasicos para analizar una encuesta a las empresas exportadoras horticolas y un modelo multinomial ordenado principalmente para determinar los factores determinantes de la competitividad empresarial. Finalmente, los resultados del trabajo indican, en general, una deterioracion de la competitividad del sector horticola especialmente durante los primeros anos de la adhesion de Espana a la U.E. La competitividad de las empresas exportadoras esta influenciada por la region, tamano, nivel tecnologico, organizacion comercial y diferenciacion del producto.
The aim of this paper is to estimate the water use efficiency of wheat farms in irrigated areas i... more The aim of this paper is to estimate the water use efficiency of wheat farms in irrigated areas in Chbika (Central Tunisia). Both Stochastic Frontier and Data Envelopment Analysis approaches were used for this purpose. Data were collected from 170 wheat farms during 2010-2011cropping season. The empirical results show that the average water use efficiency measured using the Data Envelopment Analysis (DEA) method was around 41% under constant returns to scale and 43% under variable returns to scale while it was 47% when calculated by the Stochastic Frontier Approach (SFA). This suggests that there is substantial scope for improving irrigation water use efficiency in the study region using the existing technology on wheat farms. Spearman's rank correlation coefficient between both methods in measuring irrigation water use efficiency, for our sample of wheat farms it is positive and significant at the 1% level. However, the average technical efficiencies obtained from the Stochastic Frontier method are higher than the ones estimated from Data Envelopment Analysis. This comparison shows that further empirical researches on sub-vectors efficiency calculation approaches are needed in order to obtain more accurate results than these estimations.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
This study employs stochastic data envelopment analysis (SDEA) approach for irrigation water effi... more This study employs stochastic data envelopment analysis (SDEA) approach for irrigation water efficiency measuring of wheat farms in an irrigated area of Chbika (Central Tunisia). Data was collected from 170 wheat farms during 2010-2011 cropping season. The empirical results show that the average water use efficiency for durum wheat irrigation, calculated using this approach was only around 41% under constant returns to scale (CRS) assumption; while it was 44% under variable returns to scale (VRS) assumption. This suggests that there is substantial scope for improving irrigation water use efficiency of wheat in the study region, using the existing technology on wheat farms. A Tobit regression was used to identify the determinants of the irrigation water use efficiency in the studied sample. Results of the Tobit analysis show a positive effect of wheat variety, irrigation source, membership in water users associations, irrigation scheduling and experience, on water use efficiency. These results are valuable for policy makers since they can be easily integrated in the national guidelines of irrigation water strategy.
More than 40% of irrigation water currently used in Tunisia is provided by groundwater aquifers, ... more More than 40% of irrigation water currently used in Tunisia is provided by groundwater aquifers, most of which are in a critical state of depletion due to its overexploitation during the last three decades. This paper provides a critical assessment of groundwater management in Tunisia based on interviews with key officials from central and regional administrations, in addition to farmers' questionnaires regarding attitudes and perceptions about different groundwater management instruments. Even though there is a consistent official groundwater management strategy in Tunisia, its enforcement is still problematic. Many regulatory and incentive instruments were adopted to manage groundwater but their effect was limited, partly due to the weak implementation capacities of the regional and local water administrations. Moreover, most farmers are not aware about the critical situation of this common pool resource and self-regulation initiatives are almost absent. From this assessment, we mainly conclude that the remaining activities for enhancing groundwater governance in Tunisia needs to rely on two main axes. The first is related to the improvement of administrative performances, particularly those for horizontal coordination of groundwater. The second is about investing in enhancing social capital supporting institutional changes; which is particularly necessary for the promotion of self-regulation initiatives.
This study is targeted to improve surface irrigation performance of durum wheat in swelling soils... more This study is targeted to improve surface irrigation performance of durum wheat in swelling soils. For this purpose, furrow and border irrigation trials were carried out and evaluated under different soil water depletion rates, furrow spacing and unitary inlet discharges. Irrigation was triggered whenever the soil water depletion rate reached a predetermined threshold. A comprehensive irrigation evaluation produced hydraulic, agronomic and economic indicators, such as application efficiency, distribution uniformity, crop yield, gross margin and water productivity. Experimental results showed that supplied water depths exceeded soil water deficits, inducing relevant vertical and lateral water losses. Although border and furrow irrigation crop yields were virtually tantamount (about 5.5 Mg/ha), furrow irrigation was the system of choice. An irrigation strategy based on a furrow spacing of 150 cm, an inlet discharge of 2 l/s/furrow and a soil water depletion rate of 30% required a gross water depth of 4300 m 3 /ha/yr and generated an optimum crop yield of 58 qx/ha. In the analyzed range of soil water depletion, the gross margin and water value amounted to 1064-1390 Tunisian Dinar per hectare (TD/ha) and 0.39-0.44 TD/m 3 , respectively, for a furrow spacing of 150 cm.
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