Abstract:

Aiming at the problems of insufficient prediction accuracy of winter wheat maturity stage and lack of accurate parameters at township level in Xianyang area, a study was conducted to improve the prediction of winter wheat maturity, and support agricultural machinery scheduling and disaster prevention and mitigation in Xianyang. Based on field observational data on winter wheat phenological phases and daily meteorological data from 1982-2024 from five agro-meteorological experimental stations located in Qindu District, Wugong County, Liquan County, Yongshou County and Xunyi County of Xianyang City, a prediction model for winter wheat maturity in Xianyang was established using SPSS software. Furthermore, GIS interpolation and map algebra overlay analysis were employed to determine the specific maturity dates of winter wheat at the township level in Xianyang in 2025. The results showed that: (1) from 1982 to 2024, the average temperature during the winter wheat growing season in Xianyang increased significantly at 0.46 °C /10 a (P<0.01), the growth period was shortened at -3.8 d/10 a, and the maturity period was advanced by 1.6d/10 a. All phenological phases before overwintering were positively correlated with temperature, while those after overwintering were negatively correlated with temperature(P<0.01). (2) Precipitation showed a weak increasing trend (2.2 mm/10 a), and had no significant effect on phenological period (P>0.05). Temperature was the core factor driving the change of phenological period. (3) A maturity prediction model was constructed based on winter wheat height, average temperature in March, ordinal date of sowing stage, ordinal date of flowering stage, and average temperature in early May. The model achieved a coefficient of determination (R²=0.842) and a root mean square error (RMSE=2.98), which could achieve accurate prediction at the township level 15 days in advance. The prediction of winter wheat maturity can guide agricultural departments to arrange harvesting plans rationally, provide accurate meteorological services for wheat harvesting and agricultural machinery scheduling in Xianyang City, ensure that wheat is harvested at the optimal time, and offer theoretical support for improving wheat yield and quality.

Key words: winter wheat, maturity stage forecast, SPSS, GIS, Xianyang area