EFFECT OF NITROGEN LEVELS AND ITS APPLICATION SPLITTING ON GRAIN YIELD OF BARLEY (HORDEUM VULGARE L.)

Abstract

A field trail was conducted at the of Field Crops Department, College of Agriculture, University of Baghdad during the winter growing season of 2013-2014. The objective was to identify the best nitrogen fertilizer level and the most suitable time of application based on certain growth stages of shoot and plant of Barley cv. Ibaa99 and its relationship with grain yield. The experimental design was in randomized complete block design (RCBD) with four replicates. This trail included two factors: nitrogen fertilizers levels (50, 100, 150 and 200) Kg N.ha-1 and timings of application (double ridges stage, maximum spikelet number and booting stage). Grain yield characteristics were measured and determined. The obtained results indicated the following: The level 150 Kg N.ha-1 gave the highest values of number of spikes.m-2, 1000 kernel weight, grain yield (3.622 t.ha-1), biological yield and harvest index. The splitting of nitrogen application at all treatments increased the grain yield compared with the conventional method of application (Treatment A), in particular, treatment B (four additions) and C (three additions) which gave the highest grain yield (3.501 and 3.500) t.ha-1 for each compared with 2.019 t.ha-1 for A treatment with 74% increase due to the increased spikes number (371.1 and 360.7) spike.m-2 compared with 263.3 spike.m-2 of A treatment and increased 1000 kernel weight (46.92 and 46.74) g for each compared with 45.06 g for A treatment.