Stagnating rice yields in China need to be overcome by cultivars and management improvements

CONTEXT

Understanding the dynamics of potential yields, actual yields, and their drivers is vital for developing sustainable agricultural management practices. Previous studies on rice in China, focusing on either limited experiments, limited driving factors, or short-term periods, reached inconsistent conclusions.

OBJECTIVE

We tried to investigate annual dynamics of rice potential yields, actual yields, and their gaps to distinguish the contributions of climate and technology to yield increases in major rice cultivation areas across China.

METHODS

Herein, using valuable field trials from 1981 to 2018 across 205 agro-meteorological stations and the crop model CERES-Rice, we explored the spatiotemporal trends of rice yields and quantitively separated the contributions of various factors to yield increases across mainland China.

RESULTS AND CONCLUSIONS

A contrasting trend in potential yields was observed, with a decline in the Middle and Lower Reaches of the Yangtze River (MLRYR, −22.4 kg ha⁻¹ y⁻¹) and an increase in the Northeastern China Plain (NECP, 20.0 kg ha⁻¹ y⁻¹). Despite varying regional trends, the national yield gap narrowed to 27 % in 2018. Technological advances were the primary drivers (37.3 kg ha⁻¹ y⁻¹) of yield increases in most areas compared to climate impact (−2.6 kg ha⁻¹ y⁻¹). Particularly in the MLRYR, technological improvements have offset the negative impacts of climate change. Cultivars improvement contributed (14 %–22 %) more than water and fertilizer management did in the main rice-producing regions.

SIGNIFICANCE

Our findings discover the evolving patterns of potential rice yields across China and the underlying drivers, providing scientific evidence for hindering rice yield stagnations by cultivars improvements and field management optimizations.