Volume 4 Article informations Effect of clay amendment on the conservation of moisture in sandy soils of South East Tunisia Nissaf Karbout a,* , Ines Gasmi a , Mohamed Moussa a , Habib Bousnina b Abstract Sandy soils in arid regions of southern Tunisia is characterized by a low clay content which leads to strong leaching minerals and fertilizers, it therefore results in decrease in fertility and the retention capacity of the water, in such a situation, our attention is directed to the use of local products to correct the problem of infiltration of sandy soil and increased the useful reserve. The bentonite clay is used with the sandy soil in three sets at different depths in the soil with different percentages: 5 %, 10 %, 15 %, and 20 % to have their effect in the water conservation and in the moisture in the soil. Bentonite is used in two types of clay gravel and powder the experience includes 3 lots: lot with clay sand mixture in different percentage and two lots when the mixed layer is included between two layer of pure sand with different thickness, the result shows that incorporation of clay in the soil increases the retention of water in the soil for gravel clay as powdered clay and preserve humidity not in the clay layer s only but also in the sandy layers overcome Key words: Sandy soil, Bentonite, Water conservation, Soil moisture.