Construction of flood protection works irrigation projects and for urban and industrial water use have resulted in less water to transport more salts and wastes. In addition, the river has been confined to a relatively narrow bed that prohibits flooding and leaching of salt of surrounding areas. Presently the river is characterized by decreasing water quality downstream and increasing areas of saline soils along the floodplain that permit extensive areas of salt cedar stands to thrive to the detriment of the native flora and fauna. For the ecological restoration and sustainable management of the 180-mile Middle Rio Grande Bosque it is absolutely necessary to maintain a favorable salt balance. Therefore, our research has been focused on the detection of spatial and temporal controls of soil salinity and the development of techniques that contribute to sustainable salinity management in the entire Middle Rio Grande Bosque.
Soil salinity is characterized by extremely high temporal and spatial variability.
We therefore introduced an efficient measuring technique, the ground conductivity meter for rapid characterization of soil salinity. This map, based on more than 20,000 measurements facilitates the identification of major processes leading to salinization such as capillary rise from the groundwater, insufficient leaching of salts introduced with irrigation water and seepage from ponds. Suitable areas can be selected for different types of management, based on the salinity map and our understanding of the controls on soil salinity. Revegetation with natural species for example, should not be done at the mapped areas that are inherently saline due to high capillary fluxes, but rather in areas with consistently low salinity. Ponds should preferably be located on low permeability soils, surrounded by areas that are not susceptible to rapid salinization.