Sustainable Pathways for Maize Yield Improvement Based on Changes in Planting Practices in a Typical High-Yielding Maize Region in China

Abstract

The rapidly increasing global population places pressure on the worldwide food supply, creating an urgent need to increase food production without harming the environment. Maize (Zea mays L.) is the world's most widespread food crop, and identifying sustainable methods to increase maize yields is essential to ensure food security. This study investigates maize yield data over 15 years and the changes across major cultivation and management practices in a high-yield maize region of China (Xinjiang Ili). Integrating field trials from 2021 to 2024, the study analyzes the fundamental drivers behind the increase in maize yield per unit area and proposes sustainable pathways for enhancing future maize yield in China. Maize yields in the research area increased from 11.30 t ha−1 in 2008 to 13.85 t ha−1 in 2022. This improvement was primarily driven by increased planting density using high-density-tolerant varieties and optimized water and fertilizer management, contributing 27.4% and 39.2% to yield gains, respectively. Yield-density relationships followed a quadratic function. The older variety reached its maximum yield of 19.43 t ha−1 at a planting density of 12.17×104 plants ha−1, while the newer variety achieved 19.72 t ha−1 at 14.21×104 plants ha−1, highlighting its superior density tolerance and yield potential. Efficient nitrogen management significantly enhanced maize yields by 29.5% compared to traditional fertilization. Key yield-related traits improved markedly: kernel weight per ear (KWE; 31.4%), kernel number per ear (KNE; 4.4%), and 1000-kernel weight (1000-KW; 15.4%). Leaf area index (LAI) increased pre- and post-flowering by 9.2% and 23.2%, respectively, while biomass rose by 26.5% pre-flowering and 32.5% post-flowering. The harvest index (HI) also improved by 3.8%. These physiological and management advancements were instrumental in yield improvement. Future maize yield enhancements depend on selecting and breeding high-density-tolerant varieties alongside efficient water and nutrient management strategies. These findings provide a theoretical basis for sustainable yield improvement in other major maize-producing regions of China.

Keywords: maize, yield improvement, planting density, split fertilization, Drip irrigation