Effects of Water Application Rate and Leaching Method on Reclamation of a Coastal Salt- Affected Soil of Harawah Region, Libya

RECLAMATION of salt-affected soils depends on many factors related to soil properties, water availability and quality, method of leaching and irrigation systems. This study aimed at investigating the effects of both water supplication rate and the leaching method in reclaiming a calcareous salt-affected coastal soil (EC= 36.76 dS m-1 ESP= 23.8% pH= 8.38) using the water of the Man-made River (EC= 1.48 dS m-1 and SAR= 3.71). Disturbed soil samples were collected from the study area to a depth of 50 cm and packed into PVC cylinders (60 cm long and 10 cm i.d.).The experiment comprised the treatments of seven water application rates expressed by the averagepore volume of the soil columns (0, 2, 4, 6, 8, 10 and 12 PV) and twoleaching methods; continuous (CL) and discontinuous (DL) using a factorial design with three replications for each treatment. Soil EC, ESP and pH were determined and their relative changes to the initial values were calculated (ECrel, ESPrel and pHrel) and plotted against the number of PV of applied water to obtain the leaching curves. Reductions in parameters were significant with increasing the number of PV of water applied. The DL method proved to be more efficient than the CL method in reducing these soil parameters to acceptable levels (EC= 2.61 dS m-1, ESP= 4.61% and pH= 7.78) when 10 PV of water was applied. This means that less water and longer time period will be required if the DL method is adopted. Further field research must be conducted to account for field soil variability, efficiency of irrigation systems and climate and crop conditions.