| In this paper, climate dates during1990-2009, records of wheat and corn yield over the period1992-2009and datasets of the growth process of wheat during1992-2009in3H Plain was collected. Linear regression analysis was conducted to reveal the characteristic of climate variation and production during the growth process of winter wheat and corn, correlation analysis and nonlinear regression analysis were carried out to the effect of climate factors on crop growth and development process and yield, in order to provide a theoretical basis for adaption in the future. The main conclusions were as follows:1. in recent twenty years, the daily mean, maximum and minimum temperature during winter wheat growing season increased by0.56℃,0.55℃and0.60℃per10-year on the average in the whole region, although the specific variation of temperature in different regions was different; the sowing dates were all postponed, but the heading dates and maturity dates were both advanced in2000s compared to1990s; although the determination coefficients were low in each region, the detrend of periods from sowing to heading were showed, while the trends of period from heading to harvest were increased under temperature increasing, and the dates of whole growing season were decreased expect; according to the ratios of dates from heading to harvest (S2) to those of whole winter wheat growth season since1992, the dates of S2has more scale in the whole growth season in the six regions, and it was found that the effect of temperature factors on the dates of stage S2from heading to harvest was significant, while negative correlation coefficients were found between average temperature, maximum temperature and minimum temperature and dates of stage S1; according to a nonlinear regression analysis between temperature and yield without agricultural technical improvement or other non-climatic factors, warming minimum temperature resulted into the decreasing yield in the southeast areas in Jiangsu and Shandong province. However, in the middle area,such as Anhui, Henan and Hebei province, each temperature factors could lead to winter wheat production increased.2. An upward trend was found out in the temperature during the growth season of corn in Huang-Huai-Hai area since1990. The precipitation in north regions, Jing-jin region, Hebei and Shandong province, was reduced, while it was found increase in Henan, Anhui and Jiangsu province. Compared to90s, the growth process of corn in3H area was significantly changed since2000. The whole growth stageswere prolonged with vegetative period shortened and reproductive stage prolonged since1992. Different correlations were found between each growth duration and temperature factors. The corn production in3H area was increased expect in Jiangsu province. According to a nonlinear regression analysis between temperature and yield without agricultural technical improvement or other non-climatic factors, increasing trend in north and west region was showed, while reduction was found in southeast area with warming climate. Positive effect of precipitation on yield was found in north area, where was lack of water, while negative infulunce was showed in south area. In addition, the corn production was significantly and negatively affected by increasing GDD30, especially in Shandong province, and regionally affected by increasing GDD10.3. The growth process in the whole crop system of wheat and corn has changed obviously, sowing date and mature date were both postponed, and the whole process was prolonged in corn; in wheat season, the sowing date was postponed and the mature date was advanced, caused into shortening in the whole growth process. The actual production in3H area was significantly increased. The effect of warming temperature on production was showed positively in north area and negatively in south area, which were similar to those in precipitation without agricultural technical improvement or other non-climatic factors. |
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