Timing of nitrogen applications for rice (2008)

Subasinghe, R Dunn, T Wornes, D.L Beckaz, K


This IREC farmers newsletter article presents a summary of five years of experiments investigating a suite of timings for nitrogen fertiliser application. Results indicate no significant differences in nitrogen responses among Australian rice varieties and optimum nitrogen requirement lies around 170–180 kg N/ha depending on the inherent soil nitrogen supply . Five years worth of results show that the best yields are obtained when nitrogen application is split between pre-flood and panicle initiation applications. A minimum pre-flood application of 90 kg N/ha in continuously cultivated bays is recommended to ensure adequate nitrogen supply during the vegetative growth stage of the crop to produce sufficient biomass to sustain a good yield. A maintenance requirement of nitrogen at panicle initiation is recommended to ensure adequate nitrogen supply to the plant during the reproductive stages. Mid-tillering nitrogen applications are warranted if an inadequate amount of pre-flood nitrogen was applied, early nitrogen application was not managed correctly, or the soil is inherently low in fertility