No abstract

No abstract

A field experiment on the effects of drip irrigation (DI) and subsurface drip irrigation (SDI) with saline water (6.57 dS m -1 ) on three tomato cultivars (Lycopersicon esculentum Mill., cvs. Río Tinto, Río Grande and Nemador) was carried out with the purpose to quantify physiological responses. The aim was to improve irrigation water management under saline conditions of Tunisia. The trial was established in a siltclayey soil with three regimes of irrigation: 100 %, 85 % and 70 % of crop water requirement. Results evidenced a significant difference between the two irrigation systems for the three cultivars. Growth parameters such as leaf area, chlorophyll content and mineral composition of leaves, petioles, stems and roots were affected significantly by the different treatments, particularly for Río Tinto and Nemador, being Río Grande the more adapted. The fruit was the organ less affected. Strong accumulation of Na + and Cl -accompanied a reduction in Ca 2+ , K + , Mg 2+ and P content in the case of DI. The distribution of these last necessary elements for plants nutrition under a strong accumulation of Na + and Cl -depends on the cultivar and changes from one organ to another. SDI can be included as an effective option for tomato production in Tunisia.

No abstract

No abstract

Treated wastewater (TWW) may contain toxic chemical constituents that pose negative environmental and health impacts. In this study, soil samples under treated wastewater irrigation were studied. For this purpose, six plots were made in an irrigated area in north of Tunisia and treated with two water qualities: fresh water (FW) and treated wastewater (TWW). Five soil depths were used: 0-30, 30-60, 60-90, 90-120 and 120-150 cm. The TWW irrigation increased significantly (P≤0.05) the soils’ EC, Na, K, Ca, Mg, Cl, SAR, Cu, Cd and Ni and had no significant (P ≤0.05) effect on the soils’ pH, Zn, Co and Pb contents. EC, Na, Cl, SAR, Zn and Co increased significantly with soil depth. The results for K, Ca, Mg, Cd, Pb and Ni exhibited similar repartition in different layers of soil. It was also shown that the amount of different elements in soil irrigated with fresh water (FW) were less compared with the control soil.

Portable X-ray fluorescence (PXRF) technology can offer rapid and cost-effective determination of the trace elements concentrations in soils. The aim of this study was to assess the influence of soil moisture content under different condition on PXRF measurement quality. For this purpose, PXRF was used to evaluate the soil elemental concentrations for Ca, Mg, Cd, Cr, Cu, Ni, Zn, P, Fe, Mn and Pb in 60 samples in a perimeter irrigated with treated wastewater (Cebala Borj Touil, North-east Tunisia). Scanning was conducted under four moisture conditions: in-situ, dried soil at 105°C, 40% moisture content soil and saturated soil.All were then compared relatively to dried sample scans. As expected, the relationship between dried vs both in-situ and 40% moisture content elements concentrations were linear.However, PXRF readings from saturated samples were significantly underestimated compared to the measurements on dry samples. Furthermore, soil moisture content caused a significant under-reporting of elemental concentrations compared to the scanning on dry samples. PXRF acted differently for each element following the moisture content of soil. In fact, attenuation coefficient σ of Cr, Fe and Mn were the most affected by saturation of soil samples, whilst Ca, Mg and Ni were more affected for 40% moisture content while Cd, Pb, Zn, Cu and P were affected for in-situ measurements. Correction equations enhanced the error produced by the water influence moisture content and corrected PXRF measurements.

No abstract