The Characteristics Of Heat Resources And Its Effect On Different Growth Stages Of Rice In Heilongjiang Province

Heilongjiang Province is relatively lack in heat resources and it is the limiting factor for rice production.Clearing and definiting the characteristics of heat resource changes in Heilongjiang Province and its influence on the growth of rice at different growth stages has meaning to understand and evaluate the effects of climate changes on rice production.However,studies on the yield of Japonica rice in Heilongjiang province and its response to heat resources in different growth stages are rarely reported.This paper makes use of daily average,maximum and minimum temperatures,and rice growth and yield data from 28 agro-meteorological stations in Heilongjiang province from 1974 to 2016,and uses different methods including inverse distance spatial interpolation,linear propensity estimation,SPSS correlation analysis,and MK mutation detection.Data processing methods to analyze the temporal and spatial characteristics of heat resources and their effects on rice growth and yield in different growth stages in Heilongjiang Province.They can provide a scientific basis for understanding and evaluating the impact of climate changes on rice production.The results of the studies are as follows:(1)The daily,average,maximum,minimum temperature,and ?10°C accumulative temperature of within each growth stages of rice presented a wave-like increasing trendency as a whole.The diurnal range in temperature presented a decreasing trendency overall.The decrease in the daily temperature range is caused by the increasing of the daily minimum temperature is greater than that of the maximum temperature.The heat resources In Heilongjiang Province within the rice growth stages spatially increase from east to west from north to south.(2)The number of days during the duration of rice growth in the whole growth stage of Heilongjiang Province has a tendency of increasing by 0.3d every 10 years.The days of reproductive growth and vegetative growth presented a decreasing trendency,decreasing by 0.13 days and 0.3 days every 10 years.The number of consecutive days of vegetative growth and reproductive growth presented an increasing trendency,increasing by 0.85 days every 10 years.Because the increasing range of vegetative and reproductive growth is greater than the sum of reductions in vegetative and reproductive growth stages,the duration of the entire growth stages increases.Actual production has increased since 1974,with an increase of 1608 kg per hectare for every 10 years.Trending production is on the increase,with an increasing of 1557 kg per hectare for every 10 years.Meteorological production presented a rising trendency,with an increasing of 50.4 kg per hectare for every 10 years.(3)The meteorological yield are significantly related to temperature of vegetative growth and reproductive growth ?10°C,minimum temperature during vegetative growth stage,and average temperature during vegetative growth stage at 0.01 level.The correlation coefficients were 0.537,0.554,and-0.564,.The meteorological yield was significantly bound up with the minimum temperature in the reproductive growth stage,the maximum temperature in the vegetative growth period,and the average temperature in the reproductive growth stage at 0.05 level.The correlation coefficients were 0.318,0.354,and 0.349.Meteorological production is not related to the remaining indicators.(4)The number of days in the vegetative growth stage was significantly related to the lowest temperature during the vegetative growth stage and the highest temperature in the vegetative growth stage at 0.01 level.The correlation coefficient is-0.501,-0.606.The number of days of vegetative growth and the vegetative growth stage of ?10°C,the temperature of vegetative growth and reproductive growth,and the average temperature of vegetative growth and reproductive growth and progression were significantly related at 0.05 level.The correlation coefficient is 0.337,0.33,-0.337.The number of days of vegetative growth was not related to the remaining indicators.The number of days of vegetative growth and reproductive growth and the period of vegetative growth and reproductive growth with a ?10°C accumulated temperature were significantly related at the 0.01 level,with a related coefficient of-0.719.The number of days of vegetative growth and reproductive growth and the average temperature of the vegetative growth stage were significantly related at the level of 0.05,and the correlation coefficient was 0.31.The number of days between vegetative growth and reproductive growth was not related to other indicators.There was a significant correlation between the number of days of reproductive growth and the reproductive temperature of ?10°C,and the average temperature of vegetative growth at the level of 0.01.The correlation coefficient was-0.719,0.559.There was a significant correlation between the number of days of reproductive growth and the average temperature of reproductive growth at the level of 0.05,with a correlation coefficient of 0.33.The number of days of reproductive growth is not related to the remaining indicators.