Response of Maize to Nitrogen Sources and Application Rates in a Calcareous Soil at Nubaria Region in Egypt

A field experiment was conducted at the experimental farm of Nubaria Agricultural Research Station, Agricultural Research Center (ARC), Ministry of Agriculture and Land Reclamation (MALR), El-Behiera Governorate, Egypt. The aim of the study was to evaluate the effect of different nitrogen fertilizer sources(anhydrous ammonia, Aque ammonia, Urea ammonium nitrate, Ammonium nitrate and urea) and rates (60, 90, and 120kg N/fed) on maize growth parameters (plant height, weight, and leaf area), yield components (ear weight, and 100-grain weight), stover and grain yields, NPK uptake, and N-use efficiency of maize grown in a calcareous soil. A split-plot design with three replicates were used. Five nitrogen sources represented the main plots and three N-rates represented the sub-plots. Maize SC 162 cultivar was used. The results indicated that, there were significant effects of the tested treatments on growth parameters (plant height, plant weight, and leaf area) and yield components (ear weight and 100-grain weight) parameters. These results showed no significant effect of N-sources on maize stover and grain yields. The highest grain yield of (2.98 ton/fed) was recorded for the liquid urea ammonium nitrate treatment (LUAN), while the lowest (2.76 ton/fed) was recorded for ammonium nitrate (AN) treatment. The N-rate treatments had a significant effect on maize stover and grain yields. The grain yields of 3.4, 3.1, and 2.01 ton/fed were recorded for the 120, 90, and 60 kg N/fed treatments, respectively. Results revealed also that, NPK (%), NPK uptake and total NPK uptake were significantly affected by N-sourceand N-rate treatments. There was no effect of N-sourcetreatments on N-use efficiency (NUE). The highest NUE (33.83 kg grain/kg) N was recorded for the LUAN treatment, while the lowest (30.89 kg grain/kg) N was for the urea treatment. The N-rate treatments had significant effect on NUE. and the obtained values were 34.3, 33.5 and 28.3 kg grain/kg N for 60, 90, and 120 kg N/fed treatments, respectively.