Adaptation to Climate of Corn Planting in Northeast China
A comprehensive understanding of the adaptability of maize to the climate of the planting area at the regional scale is helpful for the selection and promotion of maize varieties according to local conditions, matching the variety characteristics with the regional light and heat resources, tapping the production potential of maize varieties, and maximizing the use of light and heat Resources, reduce the impact of adverse weather conditions, and increase the yield and total yield of corn in Northeast China. Methods In this study, the Zhengdan 958 variety with strong versatility was used as the test material, and the local main planted variety was used as the control. 28 experimental sites were arranged in the range of 40°-48° north latitude during 2007-2009 to carry out multi-site networking and collaboration for many years. The experiment, combined with the meteorological data over the years, analyzed the yield performance, increase potential, growth process and accumulated temperature demand characteristics of Zhengdan 958 in the northeast region. Based on the meteorological data of the northeast region in the past 20 years, the method of geographic information spatial analysis was used to analyze the northeast region. The maturity planting zoning of maize varieties is carried out in order to provide a theoretical and practical basis for the rational layout and promotion of varieties in the spring-sown maize area in Northeast China.
The research results are summarized as follows: 1 The relationship between corn yield, growth process and climatic conditions in Northeast China In the spring corn area of Northeast my country, the growth and development process and yield of Zhengdan 958 show great differences with different heat conditions. From the southernmost experimental site in Haicheng, Liaoning, to the northernmost experimental site in Arong Banner, Inner Mongolia, its output, yield components, and growth and development period all showed strong changes; the number of days in the whole growth period from sowing to maturity/harvest, Thousand-grain weight and yield first increase and then decrease with latitude. The days of emergence and the days from emergence to spinning increase with the northward movement of latitude, and the days from spinning to maturity decrease with the increase of latitude; the yield and thousand-grain weight from spinning to maturity are respectively related to the accumulated temperature. It has a quadratic relationship with rainfall.
"The heat resource is the main factor affecting the growth of food crops in the three northeastern provinces." said Qian Shuan, a researcher at the Agricultural Meteorological Center of the Central Meteorological Observatory. In the past 50 years, the proportion of corn and rice sown area and total output in food crops in Northeast China has doubled. Among them, the corn planting area and output in 2011 were 173.53 million mu and 58 million tons, respectively, an increase of 1.4 times and 5.6 times compared with 1970.
“The expansion of crop planting areas in the north has helped increase grain production in Northeast China, but it has also increased the risk of early frost and drought and water shortage.” said Cao Tiehua, an associate researcher at the Jilin Academy of Agricultural Sciences. The date is generally late, but in recent years, early frosts in the north-central part of Northeast China have occurred from time to time, which has a certain impact on grain production. "
The relationship between climatic conditions and corn fertility. Guangdong winter corn is sown from late October to early November, and matures in the middle and late March of the following year. The full growth period of mid-maturing seeds is 130-150 days. It is in the seedling period from November to the first half of December. At this time, the temperature is still high, the sunlight is more, and the rainfall is reduced. It is suitable for corn growth and is conducive to corn "squatting seedlings". After the jointing of corn, it enters the young ear differentiation stage and is sensitive to low temperature. At this time, it has entered the early winter season, with strong cold air intrusion from time to time, and the temperature drops significantly. Late sowing corn will cause the vegetative growth period to prolong, and ear differentiation and development are vulnerable Cold damage; the tasseling and flowering period is at the lowest temperature in winter, and the heat conditions in colder years often cannot meet the requirements of maize growth. Low temperature often causes young ear differentiation, flowering, pollination and fertilization to be harmed.