Investigating the combined effect of different amounts of irrigation water and nitrogen fertilizer on maize yield and productivity in drip irrigation

Maize is one of the most important field crops in the world and Maize production with a cultivated area of about 350000 hectares and an average grain yield of 3.5 ton. ha-1 is very important and common in Iran. The purpose of this study was to investigate the effect of different levels of water and nitrogen on maize biomass, grain yield, irrigation water productivity and nitrogen productivity and finding the best irrigation and nitrogen fertilizer practices for producing Maize. Maize (SC. 704) was planted in 2018 as three irrigation treatments (I1, I2 and I3 to provide 100, 75 and 50 percent of crop evapotranspiration respectively) and four nitrogen treatments (N1, N2, N3 and N4 to provide 200, 125, 50 and zero kg of nitrogen per hectare in total, respectively) in a randomized complete block design with three replications. The results showed a significant effect of irrigation, nitrogen and their interaction effects on maize biomass and grain yield. Maximum maize biomass and grain yield were 23.02 ton. ha-1 and 12.78 kg. ha-1 for full irrigation treatment with 200 kg. ha-1 nitrogen (I1N1) treatment, respectively. Maximum irrigation water productivity for maize biomass and grain yield were 4.93 and 2.7 kg. m-3 for I2N1 and minimum irrigation water productivity for maize biomass and grain yield were 3.37 and 1.77 kg. m-3 for I1N4 treatments, respectively.