Published online by Cambridge University Press: 27 March 2009
In order to ascertain whether subsoil salts moved upwards under the influence of irrigation an elaborate investigation was carried out at the Gezira Kesearch Farm, Medani. It wasfound that the small apparent changes which occur under normal irrigation and cultivation are largely due to swelling and shrinking of the surface soil occasioned by changes in moisture content and to mechanical disturbance and settling which depend on cultivation. Apart from these apparent changes there may be a small downward movement of salt through the soil material; there is no upward movement.