This article reports the efficacy of a research-based learning (RBL) exercise on hydropedology of arid zones, with guided and open research projects (OPR) carried out by teams of undergraduate students in Oman. A range of activities and assessments was used to support student learning during the three-month course. Assessment included monitoring of field trip and lab activities, attendance recording, scrutiny by a panel of written reports and open oral presentations. Students' feedback through teaching evaluation is compared with other courses in the Department-College, illustrating high level of students' satisfaction. OPR best fit the scaffold of RBL.