Variation in nitrogen use efficiency of winter wheat

Abstract

Optimization of nitrogen fertilization to specific cultivar requirements is a major objective for improvement of trade-offs between grain yield, environmental sustainability and maximum profitable production. The aim of this study was to assess the effects of nitrogen fertilization on grain yield, and nitrogen use efficiency of modern wheat cultivars in different growing seasons. The trials with eight winter wheat cultivars and seven top-dressing nitrogen treatments were carried out in three successive growing seasons under rain-fed conditions of the southern Pannonian plain. The results from our study showed a significant variation in grain yield and nitrogen use efficiency among winter wheat cultivars when grown under different environmental and soil nitrogen level conditions. On average, grain yield ranged from 4961 to 6375 kg ha-1 among winter wheat cultivars. Increase of N soil level resulted in significant grain yield increase and nitrogen use efficiency decrease compared to the control. In 2015/16, 2016/17, and 2017/18 growing seasons grain yield of winter wheat cultivars reached plateau at 156, 175, and 128 nitrogen soil level, respectively. Significant influence of cultivar by nitrogen fertilization interaction indicated that it is necessary to adjust nitrogen fertilization to each cultivar. Moreover, notable weather variability between different growing seasons is a major limiting factor for optimal nitrogen fertilizer application in winter wheat production under conditions of the Pannonian plain.