[Characteristics of soybean climate potential productivity in frigid region and its response to climate change].

A comprehensive understanding of the evolution of soybean climate potential productivity and its response to climate change in Heilongjiang Province can offer reference and basis for further tapping soybean production potential and realizing stable and high yield of soybean in the frigid region. Based on meteorological data from 80 meteorological stations in Heilongjiang Province from 1961 to 2020, we estimated photosynthesis, light temperature, and climate potential productivity of soybean by the stepwise correction method, examined the spatiotemporal variations by spatial interpolation and statistical analysis methods, and analyzed the impact of changes in climate factors such as radiation, temperature, and precipitation on climate potential productivity. The results showed that during the study period, the average values of photosynthesis potential productivity (), light-temperature potential productivity (), and climate potential productivity () of soybean in Heilongjiang Province were 7533, 6444, and 3515 kg·hm, respectively. The temporal changes of those variables showed significant increasing trends, with increases of 125.9, 182.9, and 116.1 kg·hm·(10 a), respectively. For the spatial distribution, , , were characterized by high values in plains and lower in the mountains, and gradually decreased from southwest to northeast. Compared with that during 1961-1990, the high value zone of in period 1991-2020 expanded by 7.1%, and the low value zone decreased by 5.1%. showed a significant response to climate change. The potential temperature growth period was extended due to climate warming. The continuous increase in thermal resources, combined with relatively sufficient precipitation, effectively alleviated the negative impact of the decline in light resources on soybean production in Heilongjiang Province. The projected "warm and humid" climate would comprehensively boost climate potential productivity of soybean in Heilongjiang Province.