The regulatory mechanisms of reduced slow-release nitrogen fertiliser application on maize yield formation and nitrogen uptake, and utilisation characteristics

The excessive nitrogen application rate and low nitrogen use efficiency in maize production have become major constraints to improving green yields in Northeast China, while slow-release nitrogen fertilisers show substantial potential for enhancing nitrogen efficiency and facilitating green agricultural transformation. To clarify the yield response mechanisms and nitrogen uptake characteristics under reduced slow-release nitrogen fertiliser application, a field experiment was conducted in eastern Liaoning Province, employing various combinations of slow-release nitrogen rates and topdressing strategies. The impacts on maize growth and development, yield formation, dry matter accumulation dynamics, and nitrogen use efficiency were systematically evaluated. The results indicate that moderately reduced slow-release nitrogen fertiliser can stabilise yield while maintaining growth progression and dry matter assimilation rates during key developmental stages, significantly increasing nitrogen uptake and improving partial factor productivity of nitrogen, agronomic efficiency, and overall nitrogen use efficiency. This study demonstrates that reduced slow-release nitrogen fertiliser regimes can achieve a synergistic effect of high and stable maize yields alongside efficient nitrogen utilisation, providing scientific evidence and technical support for developing green and efficient nitrogen management strategies in eastern Liaoning and similar agroecological regions.