Variation Characteristics and Prediction Techniques of Air Temperature in Winter Wheat Field in Key Growth Periods of Winter Wheat

Zhu Baomei; Huan Haijun; Zhang Jibo; Li Manhua; Cao Changming

doi:10.16765/j.cnki.1673-7148.2025.03.009

Abstract：Using micro-climate data from winter wheat fields and ground meteorological observation data in Qihe County,Jiyang District and Shenxian County in the Northwest-Shandong plain from 2019 to 2022,this paper investigates the vertical distribution characteristics of air temperatures in winter wheat field during the late growth stages of winter wheat under late-frost and dry-hot wind conditions.Moreover,the differences in the temperatures at 150 cm height between the farmland station and the ground meteoro-logical station are compared.The prediction models of maximum and minimum temperature in different weather types and different field altitudes during key growth stages of winter wheat are constructed.The results are as follows:(1)During late-frost events,the closer the field air temperature is to the ground vertically,the lower the minimum temperature is;the earlier the temperature drops to 0 ℃,the longer the duration of below-freezing temperature is.Compared to the temperature observation at the ground weather station,the minimum temperatures recorded at farmland station are lower.The onset time of cool-ing and the time of dropping to 0 ℃ come early,and then the duration of below-freezing temperatures stays longer.(2)During dry-hot wind events,the closer the farmland field temperature is to the ground vertically,the higher the maximum air temperature,and the earlier it reaches 33 ℃,a longer duration of temperature above 33℃ will be.The maximum temperatures recorded at the field stations are higher than those at the ground observation stations.The warming onset time and the time of reaching temperatures above 33 ℃ occur earlier,and then the duration of high temperatures above 33 ℃ is longer.(3)By utili-zing meteorological elements such as air temperature,air humidity and wind speed from the ground obser-vation stations,the minimum and maximum temperature prediction models for the key growth stages of winter wheat in the farmland fields are established.The prediction accuracy of these models varies in the three counties(districts)of the Northwest-Shandong Plain,with the forecast in Qihe performing better than in Shenxian,and the forecast accuracy in Jiyang being the lowest.The minimum temperature model in Qihe has coefficients of determination(R2)above 0.904.For farmland fields,the prediction perform-ance of the maximum temperature model is better than that of the minimum temperature model.The accu-racy of the minimum and maximum temperature prediction models for cloudy and clear days is higher than that for days with partly cloudy skies.