Soil salinity related to physical soil characteristics and irrigation management in four Mediterranean irrigation districts

25 Pag., 6 Tabl., 1 Fig. The definitive version is available at: http://www.sciencedirect.com/science/journal/03783774Irrigated agriculture is threatened by soil salinity in numerous arid and semiarid areas of the Mediterranean basin. The objective of this work was to quantify soil salinity through electromagnetic induction (EMI) techniques and relate it to the physical characteristics and irrigation management of four Mediterranean irrigation districts located in Morocco, Spain, Tunisia and Turkey. The volume and salinity of the main water inputs (irrigation and precipitation) and outputs (crop evapotranspiration and drainage) were measured or estimated in each district. Soil salinity (ECe) maps were obtained through electromagnetic induction surveys (ECa readings) and district-specific ECa–ECe calibrations. Gravimetric soil water content (WC) and soil saturation percentage (SP) were also measured in the soil calibration samples. The ECa–ECe calibration equations were highly significant (P 0.1) with WC, and was only significantly correlated (P Morocco (2.2 dS m−1) > Spain (1.4 dS m−1) > Turkey (0.45 dS m−1). Soil salinity was mainly affected by irrigation water salinity and irrigation efficiency. Drainage water salinity at the exit of each district was mostly affected by soil salinity and irrigation efficiency, with values very high in Tunisia (9.0 dS m−1), high in Spain (4.6 dS m−1), moderate in Morocco (estimated at 2.6 dS m−1), and low in Turkey (1.4 dS m−1). Salt loads in drainage waters, calculated from their salinity (ECdw) and volume (Q), were highest in Tunisia (very high Q and very high ECdw), intermediate in Turkey (extremely high Q and low ECdw) and lowest in Spain (very low Q and high ECdw) (there were no Q data for Morocco). Reduction of these high drainage volumes through sound irrigation management would be the most efficient way to control the off-site salt-pollution caused by these Mediterranean irrigation districts.This study was supported by the European Commission research project INCO-CT-2005-015031.Peer reviewe

Soil salinity related to physical soil characteristics and irrigation management in four Mediterranean irrigation districts

25 Pag., 6 Tabl., 1 Fig. The definitive version is available at: http://www.sciencedirect.com/science/journal/03783774Irrigated agriculture is threatened by soil salinity in numerous arid and semiarid areas of the Mediterranean basin. The objective of this work was to quantify soil salinity through electromagnetic induction (EMI) techniques and relate it to the physical characteristics and irrigation management of four Mediterranean irrigation districts located in Morocco, Spain, Tunisia and Turkey. The volume and salinity of the main water inputs (irrigation and precipitation) and outputs (crop evapotranspiration and drainage) were measured or estimated in each district. Soil salinity (ECe) maps were obtained through electromagnetic induction surveys (ECa readings) and district-specific ECa–ECe calibrations. Gravimetric soil water content (WC) and soil saturation percentage (SP) were also measured in the soil calibration samples. The ECa–ECe calibration equations were highly significant (P 0.1) with WC, and was only significantly correlated (P Morocco (2.2 dS m−1) > Spain (1.4 dS m−1) > Turkey (0.45 dS m−1). Soil salinity was mainly affected by irrigation water salinity and irrigation efficiency. Drainage water salinity at the exit of each district was mostly affected by soil salinity and irrigation efficiency, with values very high in Tunisia (9.0 dS m−1), high in Spain (4.6 dS m−1), moderate in Morocco (estimated at 2.6 dS m−1), and low in Turkey (1.4 dS m−1). Salt loads in drainage waters, calculated from their salinity (ECdw) and volume (Q), were highest in Tunisia (very high Q and very high ECdw), intermediate in Turkey (extremely high Q and low ECdw) and lowest in Spain (very low Q and high ECdw) (there were no Q data for Morocco). Reduction of these high drainage volumes through sound irrigation management would be the most efficient way to control the off-site salt-pollution caused by these Mediterranean irrigation districts.This study was supported by the European Commission research project INCO-CT-2005-015031.Peer reviewe

Soil salinity related to physical soil characteristics and irrigation management in four Mediterranean irrigation districts

Irrigated agriculture is threatened by soil salinity in numerous arid and semiarid areas of the Mediterranean basin. The objective of this work was to quantify soil salinity through electromagnetic induction (EMI) techniques and relate it to the physical characteristics and irrigation management of four Mediterranean irrigation districts located in Morocco, Spain, Tunisia and Turkey. The volume and salinity of the main water inputs (irrigation and precipitation) and outputs (crop evapotranspiration and drainage) were measured or estimated in each district. Soil salinity (ECe) maps were obtained through electromagnetic induction surveys (ECa readings) and district-specific ECa-ECe calibrations. Gravimetric soil water content (WC) and soil saturation percentage (SP) were also measured in the soil calibration samples. The ECa-ECe calibration equations were highly significant (P   0.1) with WC, and was only significantly correlated (P   Morocco (2.2 dS m-1) > Spain (1.4 dS m-1) > Turkey (0.45 dS m-1). Soil salinity was mainly affected by irrigation water salinity and irrigation efficiency. Drainage water salinity at the exit of each district was mostly affected by soil salinity and irrigation efficiency, with values very high in Tunisia (9.0 dS m-1), high in Spain (4.6 dS m-1), moderate in Morocco (estimated at 2.6 dS m-1), and low in Turkey (1.4 dS m-1). Salt loads in drainage waters, calculated from their salinity (ECdw) and volume (Q), were highest in Tunisia (very high Q and very high ECdw), intermediate in Turkey (extremely high Q and low ECdw) and lowest in Spain (very low Q and high ECdw) (there were no Q data for Morocco). Reduction of these high drainage volumes through sound irrigation management would be the most efficient way to control the off-site salt-pollution caused by these Mediterranean irrigation districts.Electromagnetic induction (EMI) Mediterranean agriculture Irrigation management Irrigation water salinity Drainage water salinity Salt load

Proceedings of the international conference on integrated environmental Management for sustainable development. Vol. 3. Environmental and health assessment

Southern Tunisia is a region very prone to wind erosion because of its soil features, and the development of mechanized agriculture. Moreover, this region is located downwind the Sahara, which is the main source of mineral dust in the world. For these reasons, dust haze is frequently observed in this region. If some authors have already documented air quality in the northern part of Tunisia, no equivalent studies have ever been conducted for southern regions even though Dahech & Beltrando (2012) highlighted the potential negative impact of mineral dust on air quality in Sfax. This is why a ground-based station dedicated to the monitoring of mineral dust was installed at the Institut des Régions Arides (IRA) of Médenine to document the temporal variability of mineral dust concentrations in southern Tunisia. We present here the results from the two first years of measurements of meteorology, PM10 concentration, and direct solar radiation

Endogenous Starter Bacteria Associated to Chanterelle mycelia Enhance Aroma, color and growth of mycelia

Chanterelle (Cantharellus cibarius) mushroom can be cultured from its fruit body on agar medium. The present study showed that the growth rate of chanterelle mycelia in agar medium is slow whereas the pigment of the cultured mycelia was medium dependent. Different mycelia colors were detected in this study: from orange to pink and brown.This study also revealed bacterial growth near mycelia fragments, which appeared only at the initial phase of mycelia growth after which the mycelia continued to grow, blocking bacterial growth in the center of the agar plates. Therefore, we presumed that these bacteria were able to transfer the color to the chanterelle mycelia and may serve as fungal growth helper bacteria. The first step was to isolate these accompanying bacteria in pure culture and relate its phenotypical aspect to the mycelia aspect. The second step consisted of chemically treating the mycelia to suppress bacteria around and verify the myceliarsquos ability to enhance or decrease color production. As a third step, the Chanterelle mycelia were treated separately with different chemical reagents [Sodium nitrate, Potassium phosphate monobasic, Ammonium nitrate, Citric acid, Acetic acid, Boric acid (0.05 g/ml), 1% NaOH, 1% KOH and 0.5%.HCl] followed by incubation in different agar plates. We demonstrated that some treatments killed all bacteria after which the mycelia lost its growth capacity. As a final step, agar plates showing no development of mycelia were inoculated with bacteria. After this inoculation, mycelia growth resumed and obtained the color of the inoculated bacteria.nbspThe results clearly showed that endogenous bacteria present in Chanterelle mycelia serve to initiate mycelial growth and impart color to the Chanterelle mycelia. The isolated bacteria produced aromas, lecithinase, amylase and laccase as well. However, these bacteria were unable to produce oxidase, catalase or protease