Application of electromagnetic induction technique for soil salinity and sodicity appraisal

Salinity is a major problem affecting the sustainability of agriculture and environment in the Rio Grande river basin in Texas, USA. An accurate data on the spatial distribution of salinity is necessary for developing effective salinity management practices. However, at present information is lacking on the amount and distribution of salts within the Rio Grande river basin. Manual methods of salinity assessment at high spatial resolution are labor intensive, time consuming and involve expensive laboratory analysis. Electromagnetic induction technique (EMI) can be a relatively low cost, non-invasive and rapid alternative for measuring and mapping soil salinity. This project evaluated utility, accuracy and factors affecting the accuracy of EMI technique to delineate salt affected areas within the Rio Grande river basin in the Far West Texas, USA. Results of this project indicated that the EMI technique provided accurate data on spatial distribution of salinity within a geographical location. Furthermore, accuracy of EMI data was influenced by factors such as amount of clay and soil moisture content at the time of EMI survey. Results also indicated that the EMI technique is rapid, cheaper, and provides accurate spatial data at a much higher resolution than the conventional manual method.