Physicochemical and mineralogical characterizations of soils of Saïs,Morocco [Caractérisations physico-chimiques et minéralogiques des sols du Saïs,Maroc]

The sais is an agricultural excellence by which all of the land is cultivated area,the majority of soils derived from limestone lake and called tawny sands,the latter based on tortonian marls intercalated with sandstone and conglomerate. the physico-chemical and mineralogical characterization of soils representing the region sais helped to highlight the dominance of the clay fraction in vertisols and calcimagnesic soils,while it is the sands dominate the fersialitic soils. the phyllitic minerals identified are represented by the smectite,illite,kaolinite and chlorite; such type of clay plays an essential role in plant nutrition while promoting a high cation exchange activity between the clay-humus complex and soil solution. due to low levels of organic matter in soils studied; the cation exchange capacity is strongly associated with the mineral fraction,and are clays that determine the amount of exchangeable bases in soils.