Impact of Different Concentrations of Municipal Wastewater on Rice Seed Germination and Seedling Performance

Abstract— The major challenge faced by developing countries is to produce adequate food for their growing human population under the shortage of fresh water for agricultural activities. Laboratory experiment was conducted in a completely randomized design using sand medium with municipal wastewater and MR253 rice seed with the aim to evaluate effects of municipal wastewater (treated and untreated) at different concentrations (0, 2.5, 5, 10, 25, 50 and 100%) on seed germination and seedling performance. Significant (p<0.05) difference was observed between untreated and treated municipal wastewater for seedling length (SL), root volume (RV), seedling vigour index (SVI) and root: shoot ratio (R:S) while no difference were observed between untreated and treated municipal wastewater for germination percentage (GP) and the seedling phytotoxicity. The concentrations of N, P, K, Ca, Mg, Zn, Fe, Cu and Mn were higher in the untreated municipal wastewater compare to treated municipal wastewater. Seeds imbibed with untreated municipal wastewater have high seed germination and seedling performance compare to treated municipal wastewater. Inhibitory effect on chlorophyll content was observed at concentration >50% of both untreated and treated municipal wastewater while promoting effects were observed at lower (<25%) concentrations. However, all the nutrient elements were negatively and highly correlated with quantity of different municipal wastewater concentration. The study showed that seeds imbibed with untreated municipal wastewater have high seed germination and seedling performance compare to treated municipal wastewater. Municipal wastewater of <50% concentration could be recommended as a good source of water and nutrients for rice seed germination without affecting seedling performance.