| Huang-Huai-Hai region is the main producing area for summer-maize in China. There are drought and flood disasters which affect summer-maize because of the nonuniform distribution of the precipitation in this region. To ensure the high and stable yield of summer-maize on Huang-Huai-Hai region, rain-waterlogging on this region was preliminarily analysed from the point of meteorology. Secondly, assess the summer-maize yield loss caused by waterlogging from the relationship between climate facters during the summer-maize growing season and summer-maize yield. Finally, using the data of summer-maize waterlogging experiments at5points of Huang-Huai-Hai region to discuss the different effctions of waterlogging on the development and final production of summer-maize. The conclution is as follows:(1) The rainfall was concentrated among June to September in this region, which is just in the summer-maize growing season. The rainy waterlogging trends in July, August and September have gradually strengthened since2003, except June. Different stations had different trends:the rainfall among June and September in Beijing has decresed since1997, but the rainfall among June and September in Zhengzhou has increased since2003.(2) The most south and north part of Huang-Huai-Hai region had the most rainy waterlogging years between1970to2010, and the least in the middle of the region. The heavy rainy waterlogging was usually found on the south, but the low and middle grade waterlogging was occurred on the north. Anhui, Henan and part of Jiangsu province were the most severe provinces of rainy watterlogging. In the typital rainy waterlogging years, the waterlogging areas moved from south to north with the passage of the month. That is, waterlogging of June to July was placed in the south, and switched to the north in the August and September.(3) In the meteological elements of waterlogging, the rainfall and the rainy days in Henan, Shandong and Anhui has increased since2003. However, the rainfall in Hebei has decreased since1997. The sum of sunshine hours from June to September has dereased on Huang-Huai-Hai region since2000. The sum of≥10℃cumulative temperature from June to September of this region has increased since1993because of global warming in which Anhui and Heibei were the most amplitude variation provinces.(4) The rainfall, rainy days and sunshine hours during summer-maize growing season of Huang-Huai-Hai region had the certain relationship with the relative meteorological yield of summer-mazie, espetially in Anhui. Based the cloudy-moist index, the summer-maize waterlogging index in Anhui province was built to assess the waterlogging influence on the summer-maize yield. This index perfectly reflected the loss of summer-maize yield to the waterlogging.(5) The waterlogging experiments in Huang-huai-hai region suggested that waterlogging delayed the growing stage, but the dalaying days had the relation with the year of weather condition. Waterlogging shortered the hight of summer-maize, reduced the ability of potosynthesis, reduced the accumulated dry matter at the certain stage, and lowered the yield. The waterlogging in different stations had different impacts on summer-maize:the waterlogging of nanyang and hefei stations at jointing stage had more yield reduction than that of the tasseling stage, but xinyang station was just the opposite. The waterlogged of nanyang and suzhou station at jointing stage had more yield reduction than that of the tasseling stage, but xinyang station was just the opposite.There are linear relationship between waterlogging/waterlogged days and summer-maize relative meteorological yield. With the days of waterlogging/waterlogged increasing, the lower yield summer-maize got. |
PDF Full Text Request