Abstract

Abstract Determination of fertigation correct indicators in new surface irrigation methods like surge irrigation is imperative. In this research, water and nitrate losses in furrow fertigation with surge and continues flow were evaluated and compared. For this purpose, Field experiments were conducted on a soil with clay loam texture at the experimental station of the College of Agriculture and Natural Resources, University of Tehran. Different fertigation managements with surge flow included injection fertilizer during all advance cycles, wetting phase and last of advance cycle plus start of wetting phase tested. Also for continues flow, injection fertilizer in second half of advance phase and wetting phase was applied. Runoff losses of water for experiments with surge and continues flow amounted to 13.8-33.4% and 9.1-15.0%, respectively and deep percolation losses of water amounted to 9.1-17.0% and 24.5.1-34.0%, respectively. Runoff losses of nitrate in experiments with surge and continues flow amounted to 7.1-58.6% and 4.1-28.5% respectively. According to average soil depth of field, water and nitrate deep percolation losses were calculated up to 80 cm soil depth for all experiments. Nitrate deep percolation losses were negligible and there was no risk of nitrate leaching in all experiments. Results indicated that the best fertigation management for decrease nitrate runoff losses is injection fertilizer during all advance cycles and second half of advance phase in furrows with surge and continues flow, respectively. Keywords: Furrow irrigation, Fertigation, Nitrate losses, Surge flow.