title: Soil salinisation and irrigation management of date palms in a Saharan environment.
abstract: The continuance of agricultural production in regions of the world with chronic water shortages depends upon understanding how soil salinity is impacted by irrigation practises such as water salinity, irrigation frequency and amount of irrigation. A two-year field study was conducted in a Saharan oasis of Tunisia (Lazala Oasis) to determine how the soil electrical conductivity was affected by irrigation of date palms with high saline water. The study area lacked a saline shallow water table. Field results indicate that, under current irrigation practises, soil electrical conductivity can build up to levels which exceed the salt tolerance of date palm trees. The effects of irrigation practises on the soil electrical conductivity were also evaluated using model simulations (HYDRUS-1D) of various irrigation regimes with different frequencies, different amounts of added water and different water salinities. The comparison between the simulated and observed results demonstrated that the model gave an acceptable estimation of water and salt dynamics in the soil profile, as indicated by the small values of root mean square error (RMSE) and the high values of the Nash-Sutcliffe model efficiency coefficient (NSE). The simulations demonstrated that, under field conditions without saline shallow groundwater, saline irrigation water can be used to maintain soil electrical conductivity and soil water content at safe levels (soil electrical conductivity <4 dS m(-1) and soil water content >0.04 cm(3) cm(-3)) if frequent irrigations with small amounts of water (90 % of the evapotranspiration requirements) were applied throughout the year.
authors.affiliation: Water, Energy and Environment Laboratory, National Engineering School of Sfax, 3038, Sfax, Tunisia. ziedhadj@yahoo.com.
authors.forename: Zied
authors.initials: Z
authors.lastname: Haj-Amor
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: Mohamed-Khaled
authors.initials: MK
authors.lastname: Ibrahimi
authors.affiliation: Environmental, Geotechnical and Civil Materials Research Unit, National Engineering School of Sfax, 3038, Sfax, Tunisia.
authors.forename: Nissma
authors.initials: N
authors.lastname: Feki
authors.affiliation: IRD (UMR LISAH), Montpellier SupAgro, 2 place Viala, 34060, Montpellier, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Lhomme
authors.affiliation: Water, Energy and Environment Laboratory, National Engineering School of Sfax, 3038, Sfax, Tunisia.
authors.forename: Salem
authors.initials: S
authors.lastname: Bouri
mesh_terms: D057914:Agricultural Irrigation / Q000379:methods*; D003198:Computer Simulation; D003889:Desert Climate; D004553:Electric Conductivity; D004784:Environmental Monitoring / Q000379:methods*; D060587:Groundwater / Q000737:chemistry*; D008962:Models, Theoretical; D065749:Phoeniceae / Q000254:growth & development*; D054712:Salinity; D055051:Salt-Tolerant Plants / Q000254:growth & development*; D012965:Sodium Chloride / Q000032:analysis; D012987:Soil / Q000737:chemistry*; D014416:Tunisia; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D012987:Soil; D014874:Water Pollutants, Chemical; D012965:Sodium Chloride
keywords: Arid lands; Irrigation practises; Saline water; Soil salinisation