Impact of Changing Irrigation Patterns on Saltwater Dynamics of Soil in Farmlands and their Shelterbelts in the Irrigated Zone of Kalamiji Oasis

摘要

In this study, the effects of large-scale drip irrigation on the distribution of soil moisture and salt levels of farmlands (three cotton fields and one orchard) and their shelterbelts were investigated in Kalamiji Oasis in the lower reaches of Tarim River, north-west China. The following conclusions were drawn: (i) in Kalamiji Oasis, the groundwater level declined at a rate of 0.5 m yr(-1) as a result of the popularization of drip irrigation technology. Furthermore, the groundwater was shallower in non-irrigation than in irrigation seasons, with an average decline of groundwater level of more than 1 m being observed during irrigation seasons. This indicates that farmers take up water from the groundwater for supplemental irrigation; (ii) the soil salinity in shelterbelts was significantly higher than that in farmland (p0.01). This indicates the role of biodrainage in the salt control process; (iii) under the present drip irrigation practice, and without expecting results of more detailed studies, it is recommended to implement flood irrigation probably once a year in order to preserve the shelterbelts and to stimulate salt leaching. Copyright (c) 2015 John Wiley & Sons, Ltd.