Étude morpho-analytique du sol de la palmeraie de Zelfana (Sahara central algérien)

Abstract

The sustainability of soils is a major concern because they provide multiple functions such as agricultural production, water filtration and biotope for living organisms. The sustainability of crops in an arid environment requires the study of the components of this environment. Our study is carried out in the region of Zelfana (northern Sahara), 60 km from the wilaya of Ghardaïa, aims at diagnosing and characterizing the modifications of the soil produced by palm tree cultivation. Systematic sampling was carried out and soil data were measured on plots cultivated for 60 years, comparing them to those of an uncultivated area (control). The soil of the control plot is of low A/C type and deep, with a coarse texture with particulate structure, characterized by a very low organic matter content (traces), the soil is moderately to strongly calcareous, alkaline and slightly salty and has a very porous porosity with a low bulk density and low water content. The hydraulic conductivity is moderately high. In the cultivated plot, the soil is morphologically identical, of type A/C and deep with a sandy texture, with a particulate structure, characterized by a very low organic matter rate, the soil is moderately to strongly calcareous, alkaline and little to very salty and presents a strong porosity with an apparent density a little higher than that of control and low water content. The hydraulic conductivity is moderately low. The analytical results showed that the waters belong to two classes: class C3S1, poor quality for irrigation water and C4S2, poor for drainage water.The results of the annual rate of change showed that the agricultural management practiced after 60 years of cultivation has a significant impact on all studied soil parameters, especially the physical properties. These changes are justified by the effect of cropping years and farmers' management (i.e., addition of organic manure and flood irrigation). The sustainability of soils is a major concern because they provide multiple functions such as agricultural production, water filtration and biotope for living organisms. The sustainability of crops in an arid environment requires the study of the components of this environment. Our study is carried out in the region of Zelfana (northern Sahara), 60 km from the wilaya of Ghardaïa, aims at diagnosing and characterizing the modifications of the soil produced by palm tree cultivation. Systematic sampling was carried out and soil data were measured on plots cultivated for 60 years, comparing them to those of an uncultivated area (control). The soil of the control plot is of low A/C type and deep, with a coarse texture with particulate structure, characterized by a very low organic matter content (traces), the soil is moderately to strongly calcareous, alkaline and slightly salty and has a very porous porosity with a low bulk density and low water content. The hydraulic conductivity is moderately high. In the cultivated plot, the soil is morphologically identical, of type A/C and deep with a sandy texture, with a particulate structure, characterized by a very low organic matter rate, the soil is moderately to strongly calcareous, alkaline and little to very salty and presents a strong porosity with an apparent density a little higher than that of control and low water content. The hydraulic conductivity is moderately low. The analytical results showed that the waters belong to two classes: class C3S1, poor quality for irrigation water and C4S2, poor for drainage water.The results of the annual rate of change showed that the agricultural management practiced after 60 years of cultivation has a significant impact on all studied soil parameters, especially the physical properties. These changes are justified by the effect of cropping years and farmers' management (i.e., addition of organic manure and flood irrigation).