Dry drainage modeling to study the water and solutes transport in a loamy soil under barley cultivation

In recent years, researchers have considered new methods such as dry drainage, to control the soil water and salinity of the irrigated area of the fields in the arid and semi-arid regions because traditional drainage methods are expensive and need more water. Investigation of water and salts transport in these systems is essential for studying their function. In this study, effect of dry drainage on the soil water content, salinity, nitrate and chloride ion concentrations in a loamy soil was investigated using a physical model under the barley cultivation. Based on the results, dry drainage led to transport a significant part of the salts entering in the irrigated area to the non-irrigated area that accumulated on its soil surface, in addition to controlling soil moisture in the irrigated area. Based on the results, at the end of the experiment, maximum increase of salinity, nitrate and chloride concentrations on the soil surface of the irrigated area were 145, 384 and 135%, respectively, and for the soil surface of the non- irrigated area were 270, 1070 and 160 %, more than of initial values at the start of the experiment. Therefore, dry drainage system was able to control the soil salinity of the irrigated area by transporting the salutes to the non-irrigated area for proper barley growth