Single-Time Mechanical Deep Placement Fertilization Using Bulk Blending Fertilizer on Machine-Transplanted Rice: Balanced Yield, Nitrogen Utilization Efficiency, and Economic Benefits

Despite growing interest in controlled-release N fertilizers (CRNFs) because of their potential for enhancing nitrogen use efficiency (NUE) and economic returns, comprehensive impact on machine-transplanted rice remains to be understudied. To address this gap, here, we present a two-year field experiment that assessed the CRNF using mechanical deep placement fertilization (DPF) cultivation. The study involved three types (bulk blending fertilizer (BBF), polymer-coated urea (PCU), sulfur-coated (SCU)) two methods (DPF broadcast application), with high-yield split as control (CK). results showed DPF, especially SCU, greatly enhanced soil NH4+-N concentrations, NUE, yield, benefits compared application. BBF consistently exhibited superior NUE notable benefits, regardless application method used. Conversely, single-time PCU was less favorable growth. In conclusion, optimal DPF combined SCU is recommended. However, if not feasible only broadcasting possible cultivation, emerges ideal choice both high significant returns. This research offers insights improved management rice, effectively optimizing profitability.