Agriculture and Forestry
Turkish Journal of Agriculture and ForestryOptimizing water and nitrogen use for maize production under semiarid conditions
1Agro-Climatology Laboratory, Department of Agronomy, University of Agriculture,
Faisalabad-38040, Punjab - PAKISTAN
2Department of Environmental Sciences, Government College University,
Faisalabad-38000, Punjab - PAKISTAN
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 (26.90 and 27.63 Ámol m-2 s-1 during 2009 and 2010, respectively) and transpiration (5.23 and 5.43 m mol m-2 s-1 during 2009 and 2010, respectively). The highest values for leaf area index (4.93) and grain yield (8.40 t ha-1) were also recorded at this N treatment during both growing seasons. On the other hand, the mean crop growth rate (19.23 g m-2 day-1) and biological yield (16.22 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) (16.48 and 18.64 kg ha-1 mm-1 during 2009 and 2010, respectively) was achieved by application of 225 kg N ha-1 with an irrigation water depth of 525 mm during both growing seasons. Water stress at the vegetative stage reduced the grain yield by 12.2%, whereas the same treatment at the grain filling stage reduced the grain yield by 22.6%. In the semiarid environment of Pakistan, the application of water at 525 mm ha-1 with 225 kg N ha-1 gave the optimum production of the irrigated maize tested in this experiment. These crop inputs may be considered as water and N BMPs for this region or for those with similar agricultural and environmental conditions. Agricultural inputs based on these BMPs may result in similar NUE and WUE values.
Key words: Crop growth, maize yield, nitrogen use efficiency, photosynthesis, transpiration, water use efficiency
Turk. J. Agric. For., 36, (2012), 519-532.
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Other articles published in the same issue: Turk. J. Agric. For.,vol.36,iss.5.