Supplementary irrigation for managing the impact of terminal dry spells on the productivity of rainfed rice (Oryza sativa L.) in Fogera Plain, Ethiopia

Abstract

A terminal dry spell is one of the main limiting factors for rice productions. Therefore, this study was conducted to assess the effect of supplemental irrigation for managing the impact of terminal dry spells on the productivity of different rice varieties grown under rainfed conditions in the Fogera Plain. The experiment was designed in a split-plot design with water regimes as main plot factors and rice varieties as a subplot factor with three replications. The water regimes were: dry planted rainfed rice (farmers practice) (FP), transplanted but not irrigated (IWOI), transplanted and irrigated to saturation (SAT), transplanted and ponding to 1 cm water (PD1), and transplanted and ponding to 3 cm water (PD2). The rice varieties were: X-Jigna (V1), Edget (V2), Hiber (V3), Fogera-1 (V4), and Nerica-4 (V5). The combined effect of PD2 with V1 had the highest grain yield (t/ha) (4.35 t/ha) while FP with V3 had the lowest grain yield (2.12 t/ha). The highest (205%) relative grain yield was obtained when V1 was grown under PD2 followed by V4 under PD2 (199%) and V5 under PD2 (192%) compared to FP with V3. Irrigation water productivity (WP IR ) varied between water regimes x varieties from as low as 1.84kg grain mm −1 ha −1 for V3 in FP to as high as the yield of 3.07kg grain mm −1 ha −1 for V1 in PD2. The highest and lowest net benefits were recorded for V1 grown under PD2 (65, 550 ETB) and for V3 grown under TWOI (33, 500 ETB ha −1 ), respectively. Hence, the combined application of 3 cm ponding depth (PD2) with X-Jigna (V1) and 1cm ponding depth with Fogera-1 (V4) rice varieties could be suggested as effective terminal stress management to increase the yield and profitability of rainfed rice in the Fogera Plain and similar agro-ecologies.

Irrigation development as a booster of the multifunctional roles of paddy rice

“…Amarasingha et al, 2015;Anshori et al, 2021). This is particularly evident in areas where a dry spell at the end of the season can hinder rice production, as noted by Molla et al (2021).…”

Long-term spatio-temporal variability and trends in rainfall and temperature extremes and their potential risk to rice production in Bangladesh

“…Any delay in transplanting from the optimum period reduces yield and exposes the crop, particularly Aman rice, to a period with lower rainfall, thus requiring supplementary irrigation [41,56,57]. Low rainfall and/or a long period with no rainfall during the wet season adversely affects the yield of both Aus and Aman rice [58,59], and the impact is mostly statistically significant [41]. Also, extreme rainfall and floods, quite often encountered, can drastically reduce Aman rice yield [60,61].…”

Effect of Supplemental Irrigation on Growth, Physio-biochemical and Yield Responses of Mothbean (L.) Genotypes under Vigna aconitifolia Rainfed Condition in Semi-arid Regions of Rajasthan

“…Irrigation scheduling, which includes providing water that matches crop evapotranspiration and providing irrigation at critical growth stages, improves field crop water use efficiency. Water conservation by using a limited amount of water during critical crop growth stages result in a significant increase in yield and an improvement in the livelihoods of smallholder farmers in dry rainfed areas (Molla et al 2021).…”

“…Ys (Yield under stress condition), Yp (Yield under irrigated condition), SSI (Stress susceptibility index), TOL (Stress Tolerance), STI (Stress tolerance index), YI (Yield index), YSI (Yield stability index), SDI (Sensitivity drought index), DI (Drought resistance index), RDI (Relative drought index), SSPI (Stress susceptibility percentage index), GMP (Geometric mean productivity) and MP (Mean productivity) reduction in seed yield and test weight under RF condition is thought to be caused by a decrease in photosynthate assimilation and poor carbohydrate partitioning to the developing grain because of drought stress (Nathawat et al 2018). Improving the status of water through irrigation at the reproductive stage helps to sustain reproductive success and the partition of assimilates for optimum yields in waterlimited conditions (Molla et al 2021). Pearson correlation matrix plot, principal component analysis and box plot: The results of the correlation analysis for the yield and different traits in mothbean genotypes under rainfed and irrigated condition revealed the variegated strengths and directions of the relationships (Fig.…”