Abstract:

Aiming at the western Liaoning area where drought disasters occur frequently, taking spring maize as the research object, the WOFOST crop model was selected to study the model applicability in typical dry years and the evaluation of drought losses at different sowing dates.The model was driven by drought stress control test data, field test data and meteorological data.The results show that the WOFOST model after parameter calibration can better simulate the yield and loss of spring maize in typical dry years in western Liaoning province.Different sowing dates in western Liaoning province are affected by drought to different degrees, and the risk of drought reduction decreases with the delay of the sowing date.The average yield reduction rate caused by drought is about 59%-61% in 2015 (medium drought), 20%-39% in 2018 (light drought), and 36%-62% in 2020 (medium drought), respectively.The effect of drought on yield is different in different growth stages.In general, the continuous severe drought has the greatest effect on yield in joint-tasseling and tassel-milking stages, followed by tassel-milking and joint-tasseling stages.Drought in each growth period has the greatest impact on Chaoyang station, followed by Heishan station and Fuxin station.In western Liaoning province, the risk of moderate drought and severe drought in the jointing and tasseling stage increases with the sowing date, while the risk of moderate drought and severe drought in tasseling and milk-ripe stage decreases with the sowing date.When severe drought occurs continuously in the jointing and tasseling and milk-ripe stage, the degree of dry drought damage increases with the sowing date, and the yield reduction rate can be as high as 46%-84%.

Key words: WOFOST crop model, Assessment of drought loss, Typical drought years, Different sowing dates