Abstract
The objectives of this work were to determine the effect of initiating fertilizer nitrogen (N) application to winter wheat at different growth stages on grain yield and N use efficiency (NUE). A factorial experiment was carried out in two growing seasons (2011 and 2012) with five timings of first N application (GS 24/26 (tillering), GS 30, GS 31, GS 32 or GS 37) and an unfertilised control, two sowing densities (100 and 400 seeds/m2) and a cattle slurry treatment (with or without slurry). The latter was included to simulate variation in soil N supply (SNS). Delaying the first application of N from the tillering stage until GS 30 had no significant effect on grain yield in either year. Further delaying the initial N application until GS 31 caused a significant yield reduction in 2011 but not in 2012. Differences in efficiency of recovery and use of fertiliser N by the crop between the first three application timings were small. There was no evidence to support altered timing of the first application of N in response to low plant density. Slurry application did not influence SNS so the interaction between SNS and fertiliser N timing could not be determined. It is concluded that in order to maximise yield and NUE the first N application should be applied to winter wheat between late tillering and GS 30 and that delaying the first N until after GS 31 can lead to yield reductions compared to earlier application.
Original language | English |
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Pages (from-to) | 63-73 |
Journal | Irish Journal of Agricultural and Food Research |
Volume | 55 |
Issue number | 1 |
DOIs | |
Publication status | Published - 01 Jun 2016 |
Keywords
- application timing
- fertilizer efficiency
- grain yield
- nitrogen fertilizer
- wheat