Comparison of Conventional and Water-Saving Irrigation Methods for Improving Crop Growth, Yield, and Water-Use Efficiency

Abstract

To compare the performance of conventional and water saving irrigation methods in terms of growth, yield and water-use efficiency of rice (Oryza sativa L.), a comparative field experiment was conducted. The experiment was set up in randomized complete block design (RCBD) with three irrigation methods and four replications—conventional continuous flooding (CCF), alternate wetting and drying (AWD), and drip irrigation. Plot size was standardized and all other agronomic factors such as seed rate, fertilizer application, weed and pest control were the same within each treatment. The following data were taken: plant height, number of tillers, root length, days to maturity, biomass production, grain yield and total irrigation water applied, and water-use efficiency was calculated as grain yield/volume of water used for irrigation. Data obtained were analysed by the analysis of variance (ANOVA) and the means of the treatments were separated by Duncan's Multiple Range Test (DMRT) at 5% level of significance. The conventional continuous flood irrigation had the most significant effect on plant height, tiller number, root length, biomass and yield of grain, while consuming significantly more irrigation water than the two water-saving methods. Alternate wetting and drying yielded grain yields statistically identical to those obtained from conventional flooding, but also required 33% less total irrigation water, while drip irrigation required the least total irrigation water but with a small yield reduction compared to conventional flooding. These results suggest that alternate wetting and drying is the most water-saving technique while maintaining the yield, while drip irrigation, in case of severe water scarcity, is the most promising technique for water saving in sustainable crop production systems.