High grain yields of upland rice can be achieved by applying nitrogen fertilizer to previous palisade grass before planting rice. This helps increase nitrogen availability for the rice crop, leading to higher yields. Applying all nitrogen fertilizer to palisade grass 35 days before rice seeding resulted in the highest rice grain yield compared to conventional split applications. Upland rice yields were 54% higher when following palisade grass compared to ruzigrass. Adjusting the timing of nitrogen application to forage grasses can improve upland rice production sustainability and economic viability.