Experimental Study of Mulch Effect on Distribution of Soil Moisture and Salt in Fallow Season

In arid and semi-arid areas during fallow seasons, saline groundwater movement toward soil surface not only leads to soil moisture loss, but also leads to accumulation of salts in the soil salinity. In this study in order to examine the effects of mulch on soil moisture and salinity in fallow season, two laboratory model with 1×1×0.5 m which underground saline water was injected by using subsurface drainage to its soil was used. Part of soil surface was covered with wheat straw. During the 122-day simulation period, moisture and salinity were measured with HH2 sensors in three locations and five depths (10, 20, 30, 40 and 50 cm), soil samples were taken from the same locations and extraction saturate was measured. The Duncan’s test and t test are used for mean comparisons. Salinity of 0-20 cm depth in the control treatment has increased two times compared to the mulch treatment. In the final twenty days, humidity of 0-10 cm depths of mulch treatment was more than control and this difference was significant at the 5% level. So using of mulch in fallow season with the high groundwater table, it prevents the salinity of the soil surface layer.