Effects of Using Treated Municipal Wastewater on Physiological Growth Indices in Maize

In order to calculate the effects of using treated municipal wastewater on some physiological growth index of maize, an experiment was conducted in 2003, on an experimental farm in Isfahan South Treatment Plant. The experimental was designed with 5 treatments and 3 replications based on Randomize Completed Blocks. The treatments were, furrow irrigation with normal water (T1), surface drip irrigation with wastewater (T2), subsurface drip irrigation with wastewater at 15 cm depth (T3), subsurface drip irrigation with wastewater at 30 cm depth (T4) and furrow irrigation with wastewater (T5). The results indicated that, T4 had maximum leaf area index and total dry weight compared to other treatments with significant difference at 5% level. In addition, T3 had a higher value of the above parameters after T4 without significant difference compared to T2 and T5. On the other hand, T1 had shown minimum leaf area index and total dry weight. But because of the higher leaf area efficiency of light usage, in the maximum leaf area index stage, T1 had the highest net assimilation rate. In conclusion, application of treated municipal wastewater caused better yield growth compared to well water. Also, because of the better soil moisture and nutrient available at the root zone, application of wastewater with subsurface drip irrigation system at 30 cm depth, showed the highest yield growth rate.