Effect of using subsurface drip irrigation and ET‐HS model to increase WUE in irrigation of some crops
Abstract
Increasing water use efficiency (WUE) is a fundamental remedy for food production under conditions of water scarcity. The aim of this study was to evaluate the potential for water saving and yield improvements with use of the ET-HS model and subsurface drip irrigation. For this purpose, four irrigation treatments were installed in a silty loam soil at an experimental farm near the city of Isfahan in Iran in 2000 and 2001. The treatments included: surface drip irrigation (DI), subsurface drip irrigation at 15cm depth (SDI15), subsurface drip irrigation at 30cm depth (SDI30), and furrow irrigation (FI). These treatments were repeated for two genera of potato, Marfona and Navita (traditional genus of potato in Isfahan region), tomato and eggplant. In this research, a completely randomized block design with three replications was applied to each crop. Also, in all of these treatments, crop water requirement and irrigation schedules were determined by the ET-HS model. For this purpose, maximum and minimum temperature were measured daily and filled in the model. Based on the results, SDI15 has the most efficient use of water in production and is substantially different from other treatments, which measured 7.84, 3.84, 13.15 and 11.64 kg m-3 in Marfona, Navita, tomato and eggplant, respectively. The results show that the maximum crop yield occurred in SDI15 in Marfona, Navita and eggplant and in DI and SDI15 in tomato. A part of this increase in yield in SDI15 related to better soil moisture in the root zone, less water runoff, and less surface evaporation. Additionally, the results show considerable reduction of surface evaporation in SDI treatments. Finally, it can be concluded that subsurface drip irrigation, with drippers installed at a depth of 15 cm, and implementation of the ET-HS model for estimating irrigation scheduling, is the best irrigation method for Marfona, Navita, tomato and eggplant.
keywords: subsurface drip irrigation, ET-HS model, potato; tomato, eggplant, water use efficiency