Nitrogen use efficiency of bread wheat: Effects of nitrogen rate and time of application

Abstract

The experiment was conducted to assess the effects of nitrogen (N) rate and time of application on N use efficiency (NUE) of bread wheat, and their association with grain yield and protein content. Factorial combinations of four N levels, two bread wheat varieties and three timings of N applications were laid out in a randomized complete block design. N rate significantly influenced grain yield, protein content, N uptake efficiency, N biomass production efficiency, N utilization efficiency, N use efficiency for grain and N use efficiency for protein yield. Time of N application had highly significant effect on grain yield, protein content and NUE traits. Rate of N application and variety were significantly interacted to influence grain yield. Grain yield for Madda Walabu found sharply increase with each increase in N application rate. The improved variety provided significantly higher grain yield, N utilization efficiency and N use efficiency for grain yield (NUEGY) when N was applied 1/4 at planting, 1/2 at mid-tillering, and 1/4 at anthesis. Variations in NUEGY were explained more by the variations in N uptake efficiency. Harvest index contribution to NUEGY was higher for the local variety. Although NUE significantly decreased with increasing N rates, yield response of the varieties did not plateau out.

Characterization of brazilian wheat cultivars in terms of nitrogen use efficiency

“…The genotype by environment interaction (G×E) was significant for all traits, except for harvest index (HI). These results are similar to those reported by Barraclough et al (2010), Haile et al (2012) and Suprayogi et al (2011). The coefficients of variation ranged from 2.0 to 7.4%, indicating high experimental precision.…”

“…It was characterized as existing low amplitude variation in Brazilian wheat cultivars compared to the results obtained by Barraclough et al (2010) and Suprayogi et al (2011) (Figure 5a). The NHI was positively correlated with GPC K (0.49*) only in Coxilha (Figure 6f ), agreeing partially with the results reported by Haile et al (2012), who found correlations between NHI and NUtEg (0.76) and GPC N (0.42 ). Genotypes with higher values of NHI enable superior performance of GY and high GPC (Hawkesford, 2012).…”

“…The higher values of PY stood out especially for the cultivars Fundacep Cristalino (762 and 728 kg ha -1 ), BRS 220 (702 and 862 kg ha -1 ), BRS Tangará (578 and 808 kg ha -1 ) and CD 122 (626 and 774 kg ha -1 ), in Pato Branco and Coxilha, respectively (Figure 4d). The PY is an important trait because it can be directly associated with baking quality (Monaghan et al, 2001) and NUE components (Haile et al, 2012). In addition, Uppercase letters indicate significant differences among locations for the same cultivar, while lowercase letters indicate significant differences between cultivars in a particular location, according to Scott Knott test at 5% probability of error.…”

“…Several studies indicate that the NUE of wheat is lower than 60%, and range from 31 to 264 kg N ha -1 (Barraclough et al, 2010;Haile et al, 2012). The presence of genetic variability for NUE have been reported in many countries such as Mexico (Ortiz-Monasterio et al, 1997), France (Górny et al, 2011), England (Foulkes et al, 2009) Argentina (Velasco et al, 2012), and Australia (Hochman et al, 2013).…”

Influence of Nitrogen Fertilizer Application on Grain Yield, Nitrogen Uptake Efficiency, and Nitrogen Use Efficiency of Bread Wheat (Triticum aestivum L.) Cultivars in Eastern Ethiopia

“…This might be due to the genetic potential variation of the cultivars, better soil fertility and other environmental conditions in Tullo than in Meta. Cultivars variations in wheat grain yield at different nitrogen levels applications were also reported by (Hassan et al, 1998;Genene, 2003;Alam et al, 2007;Haile et al, 2012).…”