Previous PageTable Of ContentsNext Page

Effect of nitrogen fertilizer on the yield and grain nitrogenconcentration of malting barley

G. Fathi, R.C.M. Lance, G.K. McDonald

Department of Plant Science, Waite Agricultural Research Institute, University of Adelaide, Glen Osmond SA 5064

Response to N fertiliser in semi-arid areas is variable from one season to another due mainly to the variability in seasonal rainfall (3). Application of N to barley crops is now a common practice in South Australia. For malting barley, it is desirable to have varieties that have a high grain yield (GY) response to applied N but a low response in grain protein concentration (GPC). Interactions between N rate and variety have been reported in a number of cereals (2,4) but there is little information about the responsiveness of Australian barley cultivars.

Methods

A field experiment was conducted at Northfield, SA. Six lines, Clipper, Stirling, Weeah, Schooner, WI2737 and Skiff were grown under dryland conditions with 8 rates of N (0 to 105 kg N/ha with increments of 15 kg N/ha). N was applied as urea 6 weeks post-sowing. A glasshouse experiment was also conducted at the Waite Institute with 10 barley cultivars, the 6 lines from the field experiment plus WI2585, W12646, Dampier and 0 'Conner, at 2 N rates (0, 50 kg N/ha applied as urea at sowing). The soil was a sand:peat mixture and the pots were kept at either 10% or 16% moisture content (W 1,W2) by weighing the pots weekly and rewatering where necessary. Pots 120 cm deep were used for this study. Plant growth, grain yield, yield components, and N concentration of the grain and straw were measured.

Results and discussion

Wide differences in grain yield responses to N application were found at Northfield (P<0.05) (Fig. 1 a). The relative response in GY of these 6 lines was inversely related to the GPC response, although Weeah showed a much lower protein response than expected (Fig. lb). The inverse relationship between the response in yield and protein was also reported by other workers (4). There was a significant N x water interaction in the glasshouse experiment (Fig. 1 c) with response to N being greater under high levels of water. However, unlike the field experiment there was no significant variety x N effects for GY, nor was the response in GY related to the protein response. It is concluded that there is genetic variability for GY and GPC response, but that environmental factors greatly affect the responsiveness and may make selection in the field difficult.The results suggest that glasshouse screening for N responsiveness may not be very successful either. Further experiments are being conducted to examine the level of genetic variability in N responsiveness and the feasibility of selecting for this trait in malting barley.

Figure 1. (a) Grain yield response of varieties to N; (b) Relative response of varieties to two ranges of N (0, 45 kg N/ha); (c) Interaction between N and water for GY.

References

Russell, J.S. 1967. Aust. J. Exp. Agric. Anim. Husb. 7, 453-462.

Stanford, G. and Hunter, A.S. 1973. Agron.J. 65, 442-447.

Hibberd, D.E. 1978. In: Proceedings Grain Sorghum Workshop, Warwick. pp.74-94 Birch, C.J. and Long, K.E. 1990. Aust. J. Exp. Agric. 30, 237-242.

Previous PageTop Of PageNext Page