Effect of Nitrogen Rates on Dry Matter Cumulation and Nitrogen Partition of Wheat Plants Under Different Planting Methods

T WO FIELD trials were conducted at the Agricultural Experiment Station, Faculty of Agriculture Ain Shams University, Kalubia, Egypt during 2013/2014 and 2014/2015 growing seasons to investigate the response of wheat to nitrogen fertilizer rates under different planting methods. Each experiment contained twelve treatments which were the combination of four planting methods (Broadcasting (conventional tilled flat method), rows (20 cm apart), ridge (ridge width 60 cm) and bed (bed width 120 cm)) and three nitrogen fertilizer rates (60, 80 and 100 kg Nitrogen/fad (faddan = 4200 m2). Design of experiments was split plot design with three replications, where planting methods in the main plot and nitrogen rates in the sub plots. Data revealed that planting methods and nitrogen rats were significant affected on dry weight of wheat plant organs. Leaves; tillers and spikes dry weight (g/m2) were markedly increased with increasing nitrogen rates (60, 80 and 100 kg N/fad). Weight of leaves was markedly decreased by progressing plants towards maturity. On the other hand, N use efficiency (NUE) and nitrogen physiological efficiency (NPE) exhibiting maximum values, they were 42.68 kg grains/kg applied nitrogen and 43.45 kg grains/kg of N absorbed, respectively when plants were fertilized with 60 kg N/fad followed by adding 80 and 100 kg N/fad. Planting wheat on bed exhibited statistically maximum leaves, tillers and spikes dry weight (g/m2) in comparable to the other plant methods during phenological stages of wheat growth. Planting wheat on bed exhibiting maximum nitrogen use efficiency (42.50 kg grains/kg N applied) and nitrogen physiological efficiency (43.28 kg grains/kg N absorbed). Grain nitrogen yield (GNY), straw nitrogen yield (SNY) and total nitrogen yield (TNY), were increased by increasing nitrogen rates up to 100 kg N/fad under sowing methods treatment. Meanwhile 60 or 80 kg N/fad exhibited maximum values of NUE and N recovery efficiency (NRE) under sowing on ridge or on bed.