陇中黄土高原区旱地春小麦产量对干旱胁迫响应的模拟研究

为进一步探明陇中黄土高原区旱地春小麦产量形成对不同干旱胁迫的响应机制,依据甘肃省定西市安定区凤翔镇安家沟村2016—2018年大田控水试验数据以及定西市安定区1971—2018年气象数据,验证农业生产系统模拟(Agricultural production systems simulation,APSIM)模型模拟不同...

Simulation study of response of spring wheat yield to drought stress in the Loess Plateau of central Gansu

We investigate the response mechanisms of different drought stress on growth and yields of spring wheat in the Loess Plateau Region of central Gansu Province,China.In this study,we collected and analyzed field experimental data from the Anjiagou Fengxiang Town,Anding District,Dingxi City from 2016 to 2018,and meteorological data in the Anding District,Dingxi City from 1971 to 2018.The field observation data were used to verify the validity of the Agricultural Production Systems Simulation(APSIM)model under different drought stress.The effects of different growth stages and degrees of drought stress on growth,grain numbers,thousandgrain weight,and yields of spring wheat were analyzed using the APSIM model.Finally,the optimum irrigation time and quota were selected using the results from the multiple regression analysis.Our results revealed the root means square error values of the phenology dates,grain numbers,thousand-grain weight,and yield of the simulation model were less than 3.67 d,300.52 grain·m^-2,2.56 g,and 267.43 kg·hm^-2,respectively.The normalized root means square error values were less than 3.89%,2.86%,9.71%,and 11.58%,respectively.The model effectiveness index(ME)values were higher than 0.62,0.78,0.60,and 0.66,respectively.The results indicate that the model had a good fitting and adaptability under drought stress in the study area.The most influential factor for spring wheat grain numbers was drought stress at the jointing stage,followed by the emergence,tillering,no stress,heading,flowering,and grain filling stages.The most influential factor for the weight of wheat was drought stress at the grain filling stage,followed by the flowering,heading,no stress,jointing,emergence,and tillering stages.The most influential factor for wheat yield was drought stress at the grain filling stage,followed by the grain filling,heading,flowering,emergence,no stress,and tillering stages.Under different degrees of drought stress,the yield of irrigation quota of 300.00 mm was the maximum value of 4866.19 kg·hm^-2.The yield of irrigation quota of 300.00 mm increased by 283.53%,39.65%,0.46%,and 15.58%for 100.00 mm,200.00 mm,400.00 mm,and 500.00 mm,respectively.The optimal irrigation times were 1,47,60,82,and 86 d after emergence,and the optimal irrigation quota was 343.09 mm,and the yield of wheat reached maximum values of 5578.91 kg·hm^-2.A distinct interaction existed between the intensity and occurring stages of drought stress.In general,proper drought stress at the tillering stage was beneficial to increase wheat yield,but the jointing and grain filling stages were critical periods of water demand for spring wheat under drought stress.Reasonable irrigation management is needed at these growing stages to increase wheat yield.