Exploring the climate signal in the variation of winter wheat quality records in the North China Plain

Abstract

Crop quality is a critical aspect of food security, impacting end-use applications and market competitiveness. There is a well-established understanding of the impacts of climate change on crop yields, while its impacts on crop quality are often overlooked. Given the critical role of wheat in global food security and the ongoing climate change, it is essential to explore the climate drivers in shaping wheat quality. This study utilized county-level survey data encompassing eight quality indicators of wheat grain, flour, and dough during 2006–2019 acquired from 363 counties in the North China Plain, the biggest wheat-producing region in China. The complex association between variation in climate factors and wheat quality was explored using an interpretable machine learning framework. The results revealed that while technological advancements and change in cultivars have improved most quality indicators, especially for dough quality, climate variation during the entire growth period accounts for 10.7 % to 25.7 % of the variations in indicators. Water-related factors had a stronger impact on wheat quality than temperature-related factors. In irrigated zones, precipitation primarily governed test weight and falling number, whereas soil moisture played a key role in determining protein and wet gluten content. In rainfed zones, the standardized precipitation evapotranspiration index (SPEI) was the primary climatic driver of variations in test weight and falling number, while extremely high temperatures predominantly influenced protein and wet gluten content. Additionally, the SPEI exhibits interaction on most indicators with normal growing degree days (GDD). Specifically, the interactive effects between GDD and SPEI reduce dough quality under warm, dry conditions. Conversely, under warm, wet conditions, this interaction negatively impacts test weight and falling number. These findings underscore the importance of drought and the threshold effects of water availability in wheat quality prediction and adaptation, providing an overview of critical quality traits most susceptible to climate and climate extremes variations during the growing season.