Overcoming wheat yield stagnation in China depends more on cultivar improvements than water and fertilizer management

Context or problem

Crop yield stagnation has become a widespread challenge, posing severe threats to global food security. Understanding the dynamics of potential yields (Yp), actual yields and their drivers is essential for promoting sustainable agriculture production. Previous studies relied on either limited experiment and driving factors, or short-term studying periods, and have yet reached consistent conclusions.

Objective

This study aims to (1) investigate the spatiotemporal evolution of wheat Yp and Ygp across China, (2) quantify the relative contributions of climate change versus technological advancements (cultivar improvements and water/fertilizer management) to yield increases, and (3) determine region-specific strategies for sustainable intensification.

Methods

Utilizing a unique dataset spanning 38 years (1981–2018) from 306 agro-meteorological stations combined with the CERES-Wheat model, we investigate the spatiotemporal patterns of wheat yields and assess quantitatively the contributions of climate change and technological advance to yield increases across mainland China.

Results

Spatially, Northwest China has a larger yield gap (Ygp) (> 40 %) and increasing Yp trend (7.5 – 18.0 kg ha⁻¹ yr⁻¹), emerging as promising hotspot for future yield enhancement. Conversely, Yp declines with a smaller Ygp (< 40 %) and declining Yp (-15.9 – −1.5 kg ha⁻¹ yr⁻¹) in several winter wheat regions of south China.

Nationwide, technological advances contributed 59.2 kg ha⁻¹ yr⁻¹ to yield increases, offsetting climate-induced losses (-8.4 kg ha⁻¹ yr⁻¹), with cultivar improvements accounting for 53 % of technological increases compared to 47 % from water and fertilizer management.

Especially, nitrogen application exceeding 179 kg ha⁻¹ yr⁻¹ would no longer effectively drive yield increase, with cultivar improvements becoming more advantageous.

Conclusions

Our results highlight the greater contribution of cultivar improvement relative to input intensification in addressing yield stagnation, particularly under changing climatic conditions. Northwest regions require targeted irrigation modernization, while southern systems mandate nitrogen optimization and phenology-adjusted breeding to counter Yp decline.

Implications or significance

Our study quantifies the spatiotemporal dynamics of wheat yield potential and disentangles the dominant drivers across China, advocating for region-specific policies prioritizing climate-resilient cultivars and optimized nitrogen application to achieve sustainable intensification.