The Impact Of Climate Change On The Rice Yield And The Adaptation Technologies In Heilongjiang Province

In this study, two indexes of heat resources are used to study the agricultural climate change and its impact on the rice production in Heilongjiang province. One of the two indexes is ≥10 ℃active accumulated temperature(AT10); the other is the sum of monthly mean temperature for May – September(T5-9). The time series of both indexes for 63 years(1951-2013) show that in the interdecadal variations the long-term trend of the two indexes can be divided into three main phases: cold phase(1951-1993), transition phase(1993-2000) and warm phase(2000-2013). The mean accumulated temperatures and mean air temperature in the three phases are increasing with the phase progress. The averaged accumulated temperature of the warm phase was generally more than 200℃×d higher than that of the cold phase in most of Heilongjiang areas. The largest accumulated temperature increases were about 240-320℃×d in the southwestern areas of the province. During the warm period, the 2100℃×d line of the accumulated temperature had moved across Heihe area to reach Daxinganling mountain range, indicating the rice has been able to grow in Heihe area where the accumulated temperature is not enough to grow rice in the past. On the other hand, the constant rate of rice yield is higher in the area where the AT10 becomes larger as the climate warming. Besides, a comparative study between the cold period and the warm period is performed on the constant rate of rice yield and the incidence of the chilling injury of rice(the delayed-type and sterile-type chilling injury). In the cold period, the delayed-type chilling injury occurs in a higher frequency of about 3 to 4 times every 10 years in Mudanjiang area, southeastern part of the province, and in a lower frequency of about 1.5 to 2.5 times every 10 years in Songnen plain, southwestern part of the province. In contrast, in the warm period, delayed-type chilling injury almost does not occur in the rice growing areas of the province. These results state that as the climate warming the incidence of the delayed-type chilling is greatly reduced. When it comes to the sterile-type chilling injury, in the cold period, the sterile-type chilling injury occurs at a frequency of about 2 to 3 times every 10 years in Songnen plain, while at a frequency of about 1 times every 5 years in Sanjiang plain. Relatively to the cold period, in the warm period, the incidence of the sterile-type chilling injury did not reduce in most of the area, but increased in Yichun and Jixi areas. The rice varieties that adapt to climate changes are being studied. Results show that during cold period the farmer should not plant the late-maturing rice anywhere of Heilongjiang, should plant mid-late-maturing rice in Tailai county and southern part of Daqing city, and should plant middle-maturing rice in Qiqihaer City without Tailai county and northern Daqing city. The early-maturing rice should be grown in Suihua city, western Harbin city, Jiamusi city and Hegang city. During warm period, the late-maturing rice can be grown in Tailai county and southern Daqing city. The Mid-late-maturing rice can be grown in Qiqihaer City without Tailai county, northern Daqing city and western Sui Hua city. The middle-maturing rice can be grown in eastern Suihua, western Harbin, Jiamusi and Hegang. The early-maturing rice can be grown in eastern Harbin, northern Mudanjiang, southern Heihe, Yichun, Sanjiang plain, Jixi and Qitaihe. On the other hand, through power spectral analysis the two indexes all show an interannual variation in a period of 2-3 years. The same period is also found in the rice yield. This result states that it is not possible that the chilling injury occurs in a frequency of two successive years. So, a rice failure due to the chilling injury cannot occur in two successive years.