Impact of deficit irrigation and addition of biochar and polymer on soil salinity and tomato productivity

The aim of this study is to investigate impact of soil amendments (4% biochar, 0.4% polymer, and a combination of them) on soil moisture and salinity distribution, tomato yield, and water use efficiency (WUE). An open field experiments were conducted during two successive growing seasons in 2017 and 2018. The experiment consisted of three level of irrigation treatments 100%, 80% and 60% of ETc; and two different water qualities: fresh 0.9 dSm-1, and saline EC 3.6 dSm-1. Results revealed that at 100 % of ETc, soil water distribution (SWD) increased by 12.94 %, 37.87%, and 42.21% at depths (0-15cm), (15-130cm), and (30-45cm), with the addition of biochar, respectively compared with control at same depths control under freshwater, but the addition of polymer was increased by 6.35 %, 16.56 %, and 16.37 %, respectively. While combination treatments increase by 15.70%, 24.80%, and 41.26 %, at the depths afore- mentioned. Salt concentration was increased by 59.10 % with biochar, while decreasing by 7.19 % and 57.63 % with polymer and mixture treatments, respectively. The results also showed that biochar and mixture treatments improved yield compared to the polymer and control, while saline water decreased the yield compared to freshwater. With deficit irrigation, WUE was increased by 28.54%, 40.98%, and 68.93% at 100%, 80%, and 60% of ETc, respectively, indicating it could be used as an irrigation management strategy under arid and semiarid field conditions.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author