This study was conducted during 2017 and 2018 seasons on 5-year old Superior grapevines in a farm located at Minia-Abokerkas western desert road, Egypt. The aim of this investigation was to study the effect of nitrogen sources: (Calcium nitrate15.5% N as a fast fertilizer and urea form 40% N as a slow fertilizer), with two nitrogen rates (40 and 70 N units) on the growth and yield of Superior grapevines. The results showed that, the leaf N content was significantly affected by nitrogen applications. The highest value of leaf N content was 2.68-8.83% with 70 units calcium nitrate (F-70) treatment after both seasons. Leaf P content ranged from 0.11 to 0.41% in both seasons. Leaf K content was un-significantly affected by either the tested N sources or their rates, comparing to control (C) treatment. Leaf K content ranged from 0.79 to 1.41 and 0.69 to 2.00 % in 2017 and 2018 seasons, respectively. Leaf area was significantly affected by fertilizer types or rates. The leaf area (average value) could be arranged in descending order F-70 > F-40 > S-40 > S-70 in both seasons, the highest yield was recorded under urea form 40 units (S-40) and (S-70) treatments. The highest values of total soluble solids, TSS/acid ratio, total sugars, reducing sugars and the lowest values of total acidity were obtained with (S-70) treatment in the second season. Soil nitrogen content, available potassium and available phosphorus was significantly increased by the tested sources rates of fertilizers after the second season compared to the first season. The utilizing of N fertilizers either as urea form or calcium nitrate elevated the amount of N, P and K in the soil compared to control.
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