黑龙江省第一积温带春季地温变化及玉米播期分析

Changes of Ground Temperature and Spring Maize Sowing Time in First Accumulated Temperature of Heilongjiang Province

以黑龙江省第一积温带4个代表市（县）哈尔滨、双城、泰来、肇东的近10年4～5月的5～10cm土层日平均地温为基础数据，分析播种至出苗期间地温的变化规律，同时结合玉米种子萌发温度，确定该积温带的适宜播种日期。结果表明，日平均地温均随着生育进程在波动中增长，4月1～8日地温增长比较稳定，4月9—22日地温波动大，而后稳定上升；地温稳定通过6℃、7℃、8℃、9℃和10℃的平均日期分别为4月3日、4月5日、4月16日、4月17日和4月22日，但年际间差异较大；第一积温带的最早播种期建议为4月16日，适宜播种期为4月22日至5月5日。

The changes of 5-10 cm ground temperature in April and May of four representative cities and counties in the first accumulated temperature zone in Heilongjiang province in recent ten years were analyzed to obtain the sowing time in this area considering maize seed germination temperature. The results showed that daily average ground temperature was increased from 1st to 8th in April to May steadily, and a large variation happened from 9th to 22nd in April. The ground temperature steadily reached 6℃, 7℃, 8℃, 9℃ and 10℃ on April 3nd, 5th, 16th, 17th and 22nd respectively, but the date varies in different years. The earliest maize sowing time was April 16th, and the suitable sowing date was from April 22rd to May 5th.