Conservation agriculture (CA) is defined as to save the resources for agricultural crop production and it aims to achieve acceptable profits together with high and sustained production levels. Conservation tillage and mulch play a vital role in moisture conservation, water infiltration, maintaining temperature and stabilizing soil structure. In semi-arid regions, mulching has been shown to be effective in reducing the risk of crop failure at field level due to better capture and use of rainfall (Kronen, 1994). It also retards the initial evaporation of water (Bond & Willis, 1969). The capacity of the mulch to capture rain water and to retard the evaporation depends on many factors like type of mulch, biomass and rate of soil cover and physical and chemical properties. According to Findeling et al.(2007) and Coppens et al.(2007), maximum water retention of mulch particles is an important parameter in modeling the decomposition of mulch, controlling the exchanges between soil, mulch and the atmosphere and influencing the activity of soil microorganisms. In this context, the specific objectives of this study were to identify different types of mulches in the CA situations according to crop species (with pure or mixed crops), their biomass characteristics (amount, thickness) and their water retention properties.