NurulNahar, E.^1*, Zaki, M.,², Shahida, H.¹, Ernie Suryati, M. Z.², Muhammad Naim Fadzli, A. R.¹, Shajarutulwardah, M. Y.¹, Mohamad Najib, M. Y.³ and Mohamad Naim, N.¹

^{Abstract
Nitrogen (N) fertiliser plays a vital role in achieving high rice yields, but its inefficient use remains a major challenge in Malaysian rice production. This review synthesises findings from research studies, field trials and policy documents to evaluate the effectiveness of split N-splitting applications, as compared to the current Department of Agriculture (DOA) recommendations with alternative strategies and highlight the environmental and economic risks associated with excessive N use. Based on our analysis, a three-way split applying 20% of total N at the 3-leaf stage, 30% at active tillering and 50% at panicle initiation provides the best balance between crop demand, uptake efficiency and environmental protection for medium-maturity varieties such as MR 315. This targeted approach significantly improves grain yield and nitrogen use efficiency while reducing losses through leaching and volatilisation. While DOA guidelines have taken important steps by promoting split applications, recent evidence suggests that further refinement particularly in adjusting early-stage N rates, could enhance synchrony with crop uptake patterns and reduce avoidable losses. Alternative strategies such as Site-Specific Nutrient Management, enhanced-efficiency fertilisers and the 4R nutrient stewardship framework (Right Source, Right Rate, Right Time, Right Place) offers more flexible and sustainable solutions. This review proposes a revised fertilisation schedule that prioritises panicle initiation as a critical stage for N application. By integrating agronomic evidence with policy and economic considerations, we advocate for adaptive, efficiency-driven N management to enhance productivity, reduce environmental risks and support long-term sustainability in Malaysian rice systems.}

^{Keywords: nitrogen, fertilisation, nutrient use efficiency, yield, rice}

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