ANALYSE DE LA SALINITE ET DETERMINATION DE LA SENSIBILITE A LA DEGRADATION DES TERRES AGRICOLES Cas du périmètre irrigué de la Mina, Relizane

Abstract

Secondary salinization is one of the most important causes and faster degradation of irrigated areas. The contamination has already affected 15 million hectares of farmland in the only countries in North Africa and the Middle East. In Algeria the land affected by salinization represent 10-15% of the total of irrigated areas. The irrigated area of the plain of Mina (Relizane) is one of the most affected by the phenomenon of secondary salinization This study aims to characterize the state of soil salinity of a significant portion of the perimeter of Mina. The analysis focused on three parameters: - Soil Salinity - Percentage of exchangeable sodium - Structural Stability Sampling was conducted on a systematic grid with eighteen points of analysis. Treatment geostatistical data using Arc GIS software has enabled the production of maps salinity, PSE and structural stability. The superposition of the two latest cards allowed us to develop the thematic map of sensitivity to soil degradation. The study High lighted the following points: - A large part is occupied by the class very salty (43% of the area) and very salty (38%). - The class is dominant moderate alkalinity (83% of area) - The statistical analysis shows highly significant correlations between the percentage of exchangeable sodium on the one hand, the structural stability and permeability of soils on the other. The map of sensitivity to soil degradation is a tool to aid in the development of irrigated agriculture in the scope.