应用气象学报 (Jul 2021)
Construction of Soybean Chilling Damage Indicator and Its Evolution Characteristics in Northeast China
Abstract
Chilling damage is the major cause of soybean yield reduction in Northeast China. Chilling damage indicator is an important basis for the monitoring and early warning. Taking soybean in Northeast China as the research object, based on daily average temperature data of 98 meteorological stations from 1971 to 2020, the soybean growth period data and historical disaster data of 42 agro-meteorological stations from 1992 to 2020, using heat index as the indicator, the disaster sample sequences of soybean under 5 growth stages and 3 chilling damage levels are constructed by disaster data. Probability distribution fitting and Kolmogorov-Smirnov test methods are used to obtain the probability distribution of chilling damage indicator, and then the t-distribution interval estimation method is used to determine the damage level threshold, and finally the indicator is verified. In addition, the temporal and spatial characteristics of chilling disaster are studied by applying trend analysis, Mann-Kendallt test method and other methods. The results show that the perfect match rate of disaster level and chilling damage indicator is 84.4%. Therefore, this level threshold of the indicator can well reflect the occurrence of soybean chilling damage in Northeast China. Under the same chilling damage level, the threshold value of chilling damage level in the three-leaf-flowering-podding stage is higher, and that in the sowing-emergence-three-leaf stage is relatively lower. Soybean has higher heat demand in the middle and late stage of growth and development, and lower heat demand in the early stage of growth and development. The frequency of chilling damage is the highest in the 1970s, and the mutation occurred around 1993 and then showed a downward trend until 2004. The spatial distribution of chilling injury frequency in each development stage shows the same change characteristics, and the highest value area is the widest in podding-mature stage. The areas with high incidence of cold damage is the Greater Khingan Range in the northernmost of Heilongjiang Province and the Changbai Mountain in the southeast of Jilin Province. And the frequency of chilling damage shows a decreasing trend around this center. With the inter-decadal change, the high-value area gradually shrinks and the low-value area gradually expands northward.
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