Water and nitrogen are among the most important crop inputs for optimum production of maize (Zea mays L.). A comprehensive experiment was conducted during 2009 and 2010 under the semiarid conditions of Pakistan to evaluate the effects of water and N applications on the growth and yield of irrigated maize. | Research Article Turk J Agric For 36 (2012) 519-532 © TÜBİTAK doi: Optimizing water and nitrogen use for maize production under semiarid conditions Hafiz Mohkum HAMMAD1,*, Ashfaq AHMAD1, Farhat ABBAS2, Wajid FARHAD1 1 Agro-Climatology Laboratory, Department of Agronomy, University of Agriculture, Faisalabad-38040, Punjab - PAKISTAN 2 Department of Environmental Sciences, Government College University, Faisalabad-38000, Punjab - PAKISTAN Received: ● Accepted: Abstract: Water and nitrogen are among the most important crop inputs for optimum production of maize (Zea mays L.). A comprehensive experiment was conducted during 2009 and 2010 under the semiarid conditions of Pakistan to evaluate the effects of water and N applications on the growth and yield of irrigated maize. The objective was to formulate water and N best management practices (BMPs) for the above conditions. Three irrigation regimes (525, 450, and 375 mm ha-1) with 5 N rates (0, 75, 150, 225, and 300 kg ha-1) were tested using a split plot with a randomized complete block design. The results revealed that the irrigation and N treatments significantly affected growth and development of the crop plants. Photosynthesis and transpiration rates were influenced by the applied nutrients. The N application at 225 kg ha-1 resulted in maximum values for photosynthesis ( and μmol m-2 s-1 during 2009 and 2010, respectively) and transpiration ( and m mol m-2 s-1 during 2009 and 2010, respectively). The highest values for leaf area index () and grain yield ( t ha-1) were also recorded at this N treatment during both growing seasons. On the other hand, the mean crop growth rate ( g m-2 day-1) and biological yield ( t ha-1) were achieved with the 300 kg N ha-1 treatments in 2009 and 2010. Nitrogen use efficiency (NUE) was optimum at 75 kg N ha-1 during both seasons. The highest water use efficiency (WUE) ( and kg ha-1 mm-1
