Introduction. While researchers have paid considerable attention to the
effect of soil salinity on crop yield, methodological impediments remain when salinity is
combined with other growth factors, especially in farmers’ fields. A specific methodology
was adapted to assess the effect of waterlogging and salinity on date palm yield
(Phoenix dactylifera L. cv. Deglet Noor). Materials and
methods. Date palm yield, water table depth, irrigation water, groundwater and
soil salinity were measured in 167 field plots located in five irrigation sectors of the
Wargla basin (Algeria). Variance analysis and a boundary line approach were combined to
analyze actual and potential yields according to environmental stresses. Results and
discussion. High soil salinity resulted from saline irrigation water and a
shallow water table. Actual yield decreased with the increase in soil salinity, the
decrease in water table depth, and the presence of a gypsum-cemented horizon within the
soil profile. The significant effect of the interaction between water table depth and soil
salinity showed that the crop responded to the most severe stress rather than to
combinations of the individual effects. Potential yield was assessed according to classes
of water table depth, soil salinity and the occurrence of a gypsum-cemented horizon. The
relationship between soil salinity and potential yield was calibrated according to two
models. The limiting factors in order of decreasing importance were shallow water table,
high soil salinity and occurrence of a gypsum-cemented horizon for 38.3%, 16.8% and 2.4%
of the field plots, respectively; there was no limiting factor for 42.5% of the field
plots. In certain sectors, actual yields remained far below potential yields and the
additional effect of irrigation water salinity could thus be considered.