Effect of irrigation water quality (salinity - sodicity) on soil infiltration and application efficiency in furrow irrigation

Irrigation water quality is one of the parameters that affect application efficiency in furrow irrigation. Application efficiency has an important role in management and irrigation scheduling. In this investigation irrigation water qualities were applied at three different levels as control with EC=0.6 dS/m and SAR=0.9, EC=2 dS/m with SAR=10 and EC=6 with SAR=30 throughout the maize growing season. Using volume balance model, Kostiakov-Lewis coefficients were determined. Also temporal infiltration throughout the season determined for maize. These findings were used for calculating application efficiency. Results showed that the basic infiltration rate decreased during the season. At the end of season, the soil basic infiltration rate in control, EC=2 and EC=6 dS/m treatments decreased about 34, 45 and 61 % respectively as compared to beginning. Also application efficiency at the end of the season in the control, EC=2 and EC=6 dS/m decreased about 27, 49 and 62% as compared to the beginning of the season respectively. Thus, it is necessary to have proper irrigation scheduling for increasing application efficiency in furrow irrigation under saline and sodic water application.