Effects of nitrogen treatment methods on yield, nitrogen loss and nitrogen up-take efficiency of wheat cultivars

Raised bed planting system has widespread application in irrigated agriculture of several countries because of the advantages of the system provided in soil tillage, water use and production costs. This study was conducted by Transitional Zone Agricultural Research Institute in Eskisehir and Selcuk University between the years 2007-2010. Bed planting system was used in this study and the effects of spring nitrogen (N 15 -enriched urea) treatment methods (broadcasting and sub-surface application) on yields, nitrogen losses and nitrogen uptake efficiencies of two different wheat cultivars (Bezostaja1 and Alpu2000) were investigated under irrigated conditions. While treatments did not have significant effects on Bezostaja 1, they improved nitrogen uptake efficiency of Alpu2000. Nitrogen loss was 66.5% in control treatment of Alpu2000 and the value decreased to 49.2% with sub-surface nitrogen treatments. As compared to broadcasting treatments, 17.3% less nitrogen loss was achieved in sub-surface treatments. While nitrogen uptake efficiency was 19.9% in control treatments, the value reached to 33.4% with sub-surface treatments. Nitrogen uptake efficiency of sub-surface treatments was 13.5% higher than broadcasting treatments. It was concluded for bed planting system that sub-surface nitrogen treatments in spring significantly improved nitrogen uptake efficiencies and reduced nitrogen losses.