N - Use efficiency in some maize genotypes applied in the form of urea at EL-Gouba conditions
Keywords:
Nitrogen uptake, nitrogen utilization, maize genotypeAbstract
Quantification of nitrogen (N) supplying capacity in urea provides an important insight into more effective N management practices. The aims of this study were to determine the effects of contrasting soil-N levels applied by the rates (zero, 50 and 100 kg N-1ha) on the efficiency of N-uptake and N-utilization in grain mass formation examined in maize genotypes (hybrid 30k8; hybrid 3062; hybrid 3084; hybrid 310; hybrid 352 and open cultivar Kofraz, Gizasz) under EL-Gouba conditions during two growing seasons 2017 and 2018.
The study designed in split plots with four replicates, genotypes located in the main plots and N-rates in the subplots. The trails studied were: grain yield (Gy) t-1ha; biological yield (By) t-1ha; grain N content g kg-1 (Ng); plant N content g kg-1 (Nt); N using in grain formation g kg-1 (NUTE); N-uptake by the plant g kg-1 (NUP); N-uptake efficiency % (NUPE); N-use efficiency g kg-1 (NUE); and N-harvest index % (NHI). Significant differences within genotypes (p<0.01) in these trails, greatest showed in hybrid 310 regarding to Gy 6.96, 7.8 t ha-1; By 81.84, 84.84 t ha-1; Ng 12.47, 13.76 g kg-1; Nt 33.88, 34.47 g kg-1; NUP 46.84, 48.23 g kg-1; NUPE 82.77, 86.13% and NUE 17.00, 19.49 g kg-1 in both two seasons, respectively, while Kofraz superior in NUTE 31.68 g kg-1 and NHI 56.38% in first season and the hybrid 3084 in NUTE 26.82 g kg-1 and NHI 49.62% in second season comparing to the least of all trails in Gizaz in both the two seasons.
Significant increase (p<0.01) by increase N rate in By 68.29, 72.88 t ha-1; Nt 27.42, 29.05 g kg-1, NHI 47.86, 44.34%; and NUP 38.77, 41.08 g kg-1 at 100 kg N ha-1 in both two seasons, while unaffected Gy; Ng; NUTE, NUPE and NUE in both two seasons due to N-rate. All interaction of the two factors were not affected significantly in both seasons of this study. In conclusion, hybrid 310 with 100 kg N ha-1 was applicable at EL-Gouba conditions.
