Comparison of Flooded and Furrow-Irrigated Transplanted Rice (Oryza sativa L.): Farm-Level Perspectives

Abstract

The traditional irrigation methods used in rice cultivation result in a huge quantity of water loss. Exploring ways to produce more rice with less water is essential for food security. A two-season field study was initiated to compare the effect of three different proposed techniques of continuous furrow irrigation (FI) with conventional flooded irrigation (CI) on the water use efficiency (WUE) of two rice cultivars. The FI system consisted of 5-cm-wide raised beds with irrigation furrows that were 25–3 cm wide and 15–2 cm in depth. Seedlings of two rice cultivars, early-maturing (Shaka 14) and late-maturing (Giza 178), were manually transplanted (five to six plants/hill) at the same plant density (25–27 hills m−2) in different FI configurations: (1) seedlings transplanted 15 cm apart in rows along on both sides of the raised bed (FI1), (2) seedlings transplanted 22 cm apart in a center row in the raised bed and in single rows on each side of the raised bed (FI2), and (3) seedlings transplanted 22 cm apart in rows on both sides of the raised bed and on the furrow (FI3). FI treatments were compared with conventional flooded irrigation (CI) with seedlings spaced 2 cm apart at the same plant density. To maintain a water depth of 1–15 cm in the furrow, irrigation was given for furrow only. The results showed that for both cultivars, FI was superior to CI in terms of saved water, rough rice yield and, thus, WUE. The results also indicated that the highest WUE was achieved using FI3, while the highest grain yield was reached using FI1. The improved WUE (146.44%) in the FI3 system is attributed to the significant water use reduction (56.8%). Among FI techniques, both FI1 and FI3 represent good options for growers to optimize yield while using significantly less water.