Exploring the impact of potassium fertiliser rate and split ratio on rice yield and quality in China: a meta-analysis

Potassium (K) is crucial for rice yield and quality, but continuous yield increase reduces protein content, challenging the balance between high yield and quality. This study analysed 3 178 case studies (1994–2024) on K management impacts on rice yield, grain protein, and amylose content, evaluating effects of K fertiliser rates, base-topdressing ratios, planting regions, and soil properties. The results showed that K application significantly increased rice yield, protein content and amylose content by 11.6, 2.0 and 1.0%, respectively. Importantly, we identified targeted K fertilisation strategies tailored to different quality goals: optimising for eating quality, nutritional quality, or synergistic improvement of yield and comprehensive quality. This study provides a scientific basis for precision K management to help growers balance rice yield with specific quality needs.