SOIL MOISTURE DISTRIBUTION IN SANDY SOIL UNDER DRIP IRRIGATION SYSTEM USING NEUTRON SCATTERING METHOD

Abstract

This work aims to study soil moisture behavior in sandy soil under drip irrigation system in order to control the management in sandy soil using neutron scattering technique. Studying soil moisture distribution through the soil profile is important to management the irrigation water, to achieve the maximum benefit from irrigation water. To achieve this aim, an experiment was carried out at the farm of Soil and Water Department, Nuclear Research Center, Atomic Energy Authority, Inshas (latitude longitude 30˚19 N longitude 31˚27 E), during onion growing season (2008/2009). Drip irrigation system was used for applying irrigation water. The uniformity of emitters' water application was checked to judge the system. Data showed that it's possible to use the combination work between neutron scattering technique and soil moisture retention models to study the direction of soil water movement within sandy soil profile. As well as predicting some soil plant concepts (i.e., active rooting depth and depth of collective active roots for water absorption);these concepts used to determine evapotranspiration, drainage rate and active rooting zone. Detecting total hydraulic potential within the wet area around the dripper along dripper lines and between lateral lines helps to study the behavior of soil moisture values within soil profile. The obtained data show also that the actual evapotranspiration of onion plant differs from site to site in wet area according to soil moisture availability. Surfer computer program also shows soil profile can be classified into different areas after and before irrigation within the wet area around drippers. The combination work between neutron probe, soil moisture tension models and. Surfer computer program shows study the horizontal and vertical movement of soil water in the wet area around the dripper and obtaining couture lines of soil moisture within the wet area.