Impact de l intensification agricole sur la sodisation du sol dans les palmeraies de Ghardaia (cas de oued Sebseb)

Abstract

The assessment of the impact of agricultural production systems in the arid environment requires a quantitative study of the spatial and temporal evolution of the components of this environment. Our work in the Sebseb region (Ghardaïa) focuses on studying the impact of agricultural intensification (phylic farming) on the evolution of sodium soil, upstream, center and downstream of Oued Sebseb. The results obtained revealed that the soil analyzed was non-sodium in the soils of the three palm groves (Jedide, Cheaab and CheaabNacer), the study of the profiles of sodium adsorption ration; Of the control before and after irrigation and between the two summer and winter seasons shows the impact of agricultural intensification on the evolution of the S.A.R profile in both seasons in all the studied horizons. The results of the analysis showed that the applied irrigation water was varied at (C3-S1) and (C5-S4). These waters are characterized by a sulphate- magnesium facies for the palm grove of Jedid and sulphated soda for the other two palm groves (CheaabDaboub, CheaabNacer). The study of the evolution of sodicity in the cultivated plot of the three palm groves (Jedide, Cheaab and CheaabNacer) showed that there is a decrease in the SAR value after irrigation and an increase of these parameters before irrigation , Which is due to two phenomena: Leaching after irrigation and a capillary rise before irrigation. Analysis of sodium adsorption ration of soil solution in the uncultivated fielst showed that there was a decrease in this value, due to the phenomenon of leaching of salts by