[Establishment of indices for soybean low temperature damages in key growth stage in high cold region].

Establishment of indices for low temperature damage of soybeans is important for systematically analyzing the adaptation strategies to climate change and collaborative adaptation technology for disaster prevention and mitigation and other stresses in high cold region. Based on historical data of low temperature damage and phenophase of soybean from 1980 to 2020 and daily temperature data from 78 meteorological stations in Heilongjiang Province, we used GIS to match the phenophase and meteorological data, by considering the accumulated temperature anomaly in different growth stages, and constructed a comprehensive soybean low temperature damages index (CSCDI) in high cold region. Using K-S distribution fitting test and the lower limit value of confidence intervals, we constructed the level index of soybean low temperature damage. The results showed that the CSCDI lower limits of mild, moderate and severe low temperature damage were 0.061, 0.115 and 0.237 from sowing to emergence stage, were 0.072, 0.152 and 0.312 from emergence to flowering, and 0.133, 0.245 and 0.412 from flowering to maturity, respectively. The time distribution of soybean low temperature damage inversed by CSCDI in Heilongjiang Province was consistent with the historical disaster records. The spatial distribution showed obvious latitude characteristics, with the frequency of low temperature damage increasing gradually from south to north.