Deep fertilization with controlled?release fertilizer for higher cereal yield and N utilization in paddies: The optimal fertilization depth

Belowground fertilization is a prevalent strategy for considerable grain yield and N utilization. However, the optimal depth remains uncertain in paddies, especially slow/controlled release fertilizers. This study aimed to clarify effect of deep “controlled-release blended fertilizer” (CRBF) on rice (Oryza sativa L.) Two N-fertilizer types were selected (a) urea (b) CRBF, both combined at three depths 0 cm, 5 (c) 10 cm. The results showed that was significantly affected by fertilizer type depth. achieved from CRBF 7.8% higher than application. Deep could also increase with optimum 5-cm (yield increased 15.1% compared manual surface fertilization). Overall, highest among all treatments 12.21 11.84 t ha–1 2018 2019, respectively. larger sink main reason this performance. Additionally, photosynthetic efficient population after earing another principal driver CRBF. Due uptake, application partial factor productivity (PFP) recovery efficiency (RE) (P < .05); had striking PFP RE .05 or .01). utilization years. suggest controlled-release suitable