Abstract: For understanding the change rule of ground temperature in Shenyang area,providing better forecast service on field temperature,reducing the risk of sowing and improving grain production safety,based on the data of air and ground temperature from the seven meteorological stations in Shenyang area from 1981 to 2015, the change rules of air and ground temperature in recent 35 years were analyzed using mathematical statistics methods and a ground temperature forecasting model for the spring sowing period (April and May) was established.The results show that from 1981 to 2010,the decadal temperature shows an increasing trend and the change of air temperature results in an obvious change of ground temperature.The climate tendency rates of air and ground temperature are between 0.426℃/10 a and 0.549℃/10 a.In the past 35 years,the differences of ground temperature at the soil depth of 0-5 cm,5-10 cm,and 10-20 cm are 1.5℃,0.5℃,and 0.5℃ during April and October,respectively.The ground temperature at the soil depth of 0-20 cm and air temperature undergo a climate abrupt change in 1996,affecting the changing trend of temperature.During the spring sowing period,the differences between air temperature and ground temperature at the soil depth of 0 cm,5 cm and 10 cm in the western region change respectively from the low value in April to the high value in May.The t-test of the ground temperature forecast model doesn't show significant difference at P=0.01 level,and the relative error is within ±10%,indicating that the model can be applied for the prediction of ground temperature during the spring sowing period (April and May) in Shenyang area.

Key words: Shenyang area, Ground temperature, Sowing period, Forecast