Login | Request Account (DAF staff only)

Nitrogen fertiliser residues for wheat cropping in subtropical Australia

View Altmetrics

Strong, W.M., Dalal, R.C., Weston, E.J., Cooper, J.E., Lehane, K.J. and King, A.J. (1996) Nitrogen fertiliser residues for wheat cropping in subtropical Australia. Australian Journal of Agricultural Research, 47 (5). pp. 695-703. ISSN 1836-0947


Article Link: https://doi.org/10.1071/AR9960695


Applied nitrogen (N) recovered by fertilised wheat and by successive wheat crops in a 4-crop sequence (1987-90) was studied by applying 15N-depleted ammonium nitrate (0, 2.5, and 7.5 g/m2) to a Vertisol in the summer-dominant rainfall region of northern Australia. Recoveries of applied N by each of the 4 crops in order of cropping sequence were 60.3¦ 4.2, 4.4 ¦ 2.3, 1 . 3 ¦ 0.49, and 0- 8 ¦ 0.56%, there being no effect of 2 tillage treatments, conventional tillage (CT) and no till (NT), on uptake of applied N. There was very low recovery of residual fertiliser N after the first wheat crop was harvested; usually <lo% of the applied N was recovered. There was evidence of a substantial N carryover benefit where fertiliser N (7.5 g/m2) was applied in 1987, but not when applied at the same rate in 1988 or 1989. Carryover effect was shown only when fertiliser N was applied after a long fallow when antecedent NOT-N was already high (100-150 v. 30-55 kg/ha with a normal summer fallow). Carryover of subsoil NO3 -N from a single N fertiliser application to the crop, as occurred with application in 1987, will provide useful buffer for declining N supplies of soil N in seasons of good crop response. Routine application of N at moderate rates (<75 kg/ha) provides an effective means of supplementing declining soil N reserves for winter cereals in this region of unreliable rainfall.

Item Type:Article
Keywords:Vertisol, 15N-depleted fertiliser, monoculture, no till
Subjects:Agriculture > Agriculture (General) > Methods and systems of culture. Cropping systems
Agriculture > Agriculture (General) > Fertilisers
Plant culture > Field crops > Wheat
Live Archive:05 Apr 2024 00:13
Last Modified:05 Apr 2024 00:14

Repository Staff Only: item control page


Downloads per month over past year

View more statistics