Study On Maize Cold Damage In Heilongjiang Province In Recent 36 Years

Maize is one of the main food crops in Heilongjiang Province.Cold damage is one of the main meteorological disasters in maize agricultural production in Heilongjiang Province.Based on the monthly average temperature data from May to September of 83 meteorological stations and maize yield data of 22 typical counties(cities)in Heilongjiang Province from 1981 to 2016,and the meteorological industry standard,which was promulgated by China Meterological Administration in 2012,chose the anomaly of the sum of monthly average temperature from May to September as the index to judge the intensity of maize cold damage,the trend analysis method and ArcGIS spatial interpolation analysis were used to analyze the temporal and spatial distribution characteristics of light,moderate,severe cold damage and total cold damage of maize in Heilongjiang Province.Then using SPSS correlation analysis and meteorological yield,the effect of maize cold damage on maize yield in Heilongjiang Province were analyzed to provide a theoretical basis for further research on monitoring,warning and risk assessment of maize cold damage in Heilongjiang Province.Hoping to provide scientific and reasonable basis for maize planting in Heilongjiang Province and take appropriate measures to deal with cold damage,disaster prevention and mitigation.The results showed that:(1)From 1981 to 2016,the occurrence ranges of various intensities of maize cold damage in Heilongjiang Province showed a decreasing trend with time,in which the occurrence range of severe cold damage was the largest,followed by slight cold damage,the decreasing trend of the occurrence range of moderate cold damage was the smallest.(2)The distributions of the occurrence times of cold damage at different intensities and total cold damage of maize in Heilongjiang Province were not uniform,and all of them showed a decreasing trend.In the 1980 s,the occurrence times of them were the most,in the 1990 s the occurrences times of them were decreased,in the 2000 s and early 2010 s the occurrences times of them were decreased obviously,and in the early 2010 s the occurrences times of them were the least.(3)From 1981 to 2016,the slight cold damage of maize in Heilongjiang Province mainly occurred in the central,western and eastern regions of Heilongjiang Province;moderate cold damage mainly occurred in the northeast areas of Heilongjiang province;the occurrence frequency of severe cold damage showed that the north was larger than the south,severe cold damage in high incidence areas mainly located in the northwest and northern areas of Heilongjiang Province,and the low incidence areas mainly located in the southwestern and northeastern regions of Heilongjiang Province.The high incidence areas of maize cold damage in Heilongjiang Province were located in the northern regions of Heilongjiang Province,and the low incidence areas were located in the southwest and southeast regions of Heilongjiang Province.(4)The decadal distribution variations of maize cold damage in Heilongjiang Province was obvious.The occurrence frequencies of cold damage at different intensities showed a decreasing trend with decade,the distribution ranges were decreased and the minima were in the early 2010 s.The occurrence frequency of cold damage showed that severe > slight > moderate cold damage.The most frequent period of slight cold damage of maize in Heilongjiang Province was the 1980 s.It occurred in the Songnen Plain and the northwest areas of Heilongjiang Province.In the 1980 s,the occurrence frequency of moderate cold damage was relatively high in parts of the north and west of Heilongjiang Province,and the most frequent period of severe cold damage was the 1980 s,which occurred in the northwest,north and southeast regions of Heilongjiang Province.(5)There was a significant or extremely significant correlation between the anomaly of the sum of monthly average temperature from May to September of 82% of the typical stations and maize yield per unit area,and the anomaly of the sum of monthly average temperature from May to September was the index to judge maize cold damage.The results showed that the temperature of maize growing season had an important effect on maize yield,and cold damage could lead to maize yield reduction.The average proportions of negative value of maize meteorological yield when 22 typical stations occurred light,moderate and severe cold damage were 72%,85% and 81%,respectively.The average proportion of negative value of maize meteorological yield when 22 typical stations occurred cold damage was 78%.The above data fully showed that maize cold damage in Heilongjiang Province had an important effect on maize yield per unit,and cold damage could lead to maize yield reduction.