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Effect of different levels of nitrogen and plant density on grain yield and its components and water use efficiency of maize (Zea mays L.) cv. SC. 704 under different moisture conditions in Khuzestan
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Abstract: (4281 Views) |
| In order to study the effect of different levels of nitrogen and plant density under different moisture conditions on grain yield and yield components, biological yield and economic and biological water use efficiency of a maize hybrid (Zea mays L.) cv. SC. 704 a research was conducted in 2004 and 2006 cropping seasons, in experimental field in Agriculture and Natural Resources Sciences University of Khuzestan, Ahvaz, Iran. Irrigation treatments were implemented separately in three experiment in cluding. Optimum irrigation (I1), Moderate stress (I2) and Severe stress (I3) (irrigation treatments were applied based on depletion of 30%, 40% and 50% of field capacity, respectively). Until 4 to 5 leaf stage (seedling establishment stage) irrigations carried out after depletion of 30% field capacity in all treatments and after this stage irrigation treatments were applied. A split plot arrangement in Randomized Complete Block Design with three replication was used for each experiment. In each experiment three nitrogen levels (N1=140, N2=180 and N3=220 Kg N ha-1) were applied in main plots and three plant densities (D1=6, D2=7.5 and D3=9 plants m-2) were assigned to sub-plots. Results of combined analysis of variance indicated that the effect of moisture stress, nitrogen and plant densities on grain and biological yield was significant. The maximum grain yield (1050.2 gm-2) was harvested from optimum irrigation (I1). Severe moisture stress decreased the grain yield by 35% in comparison with optimum irrigation. This reduction was mainly due to reduction of grain number per ear and 1000 kernel weight. Grain yield increased with increasing nitrogen application. The yield difference between nitrogen levels was mainly due to positive effect of nitrogen on grain number per ear. The response of grain yield to increase in plant densities was positive. All yield components except number of rows per ear were sensitive to plant densities. Harvest index decreased as severity of moisture stress and plant densities increased, but there was no significant difference between different levels of nitrogen. Decreasing irrigation intervals increased economic and biological water use efficiency. The highest means of economic (1.71 kgm-3) and biological (3.28 kgm-3) water use efficiency, belonged to optimum irrigation. Increasing nitrogen application increased economic and biological water use efficiency. The response of these efficiencies to plant densities was also positive. Results of this study, suggest that in order to increase input use efficiency and decrease the costs, nitrogen consumption rate, plant densities and available water in soil should be proportionated. Under moisture stress conditions, reduction in input levels, not only decreases the costs, but also increases the efficiency of resources used. |
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| Keywords: Maize, Moisture stress, Nitrogen, Plant density, Water use efficiency |
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Full-Text [PDF 331 kb]
(1541 Downloads)
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Type of Study: Scientific & Research |
Subject:
Special
Received: 2015/02/28 | Accepted: 2015/02/28 | Published: 2015/02/28
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