Variation characteristics of climatic potential yield and resources utilization efficiency of maize under the background of climate change in agro-pastoral transitional zone of Gansu, China.

To evaluate the effects of changes in radiation, accumulative temperature, precipitation and climate resources on climate resource utilization efficiency in the agro-pastoral transitional zone of Gansu Province, we analyzed the variations of climate potential yield loss rate, light, heat, precipitation and comprehensive utilization efficiency of climate resources in the agro-pastoral transitional zone of Gansu Province by the step-by-step correction and indexation method, with the 1971-2020 weather data from 45 meteorological sites and the maize phenology data. The results showed that solar radiation showed fluctuating downward trend at a rate of -22.03 MJ·m-2·(10 a)-1, the accumulative ≥11 ℃ temperature showed significant upward trend at a rate of 60.89 ℃·(10 a)-1, the precipitation showed slow upward trend at a rate of 2.05 mm·(10 a)-1 during the study period. The climate potential yield loss rate due to temperature and precipitation limitations was relatively high in Gannan and the northern part of Longzhong, while it was relatively low in the most areas of Longdong. Except for the central part of the study area and part of Longdong, the climate potential yield loss rate due to temperature and precipitation limitations in other regions of the study area showed decreased trend at the rate of -2.0%·(10 a)-1 and -0.6%·(10 a)-1. The low-value areas of light and heat utilization efficiency distributed in the northern and southern parts of Longzhong and part of Gannan, the low-value area of precipitation utilization efficiency distributed in Gannan, and the low value of comprehensive utilization efficiency distributed in Lanzhou and Baiyin which were 0.41 and 0.47, respectively. Longdong was the most suitable for maize planting, where the climate resources utilization efficiency of maize was highest, followed by Gannan and Longzhong. The average tendency rate of light, heat, precipitation and climate resources comprehensive utilization efficiency in the study area showed increased trend, which were 0.1%·(10 a)-1, 0.07 kg·hm-2·℃-1·d-1·(10 a)-1, 1.17 kg·hm-2·mm-1·(10 a)-1 and 0.05 ·(10 a)-1, respectively, showing a good potential to increase maize yield.为评估辐射、积温、降水和气候资源变化对甘肃农牧交错带玉米气候资源利用效率的影响,基于研究区45个气象站点1971—2020年玉米生育期内气象资料,结合玉米生育期数据,利用作物生产潜力逐级订正模型和指数化处理方法对研究区玉米气候生产潜力损失率以及光能、热量、降水和气候资源综合利用效率的变化特征进行分析。结果表明: 研究期间,甘肃农牧交错带玉米生育期内太阳总辐射量以-22.03 MJ·m-2·(10 a)-1的速率呈波动下降趋势,≥11 ℃积温以60.89 ℃·(10 a)-1的速率呈显著上升趋势,降水量以2.05 mm·(10 a)-1的速率呈缓慢上升趋势。甘南地区和陇中北部地区分别因温度和降水限制导致玉米气候生产潜力损失率较高,陇东大部分地区玉米气候生产潜力损失率较低;除中部地区和陇东部分地区外,研究区其他地区因温度和降水限制导致的气候生产潜力损失率分别以-2.0%·(10 a)-1和-0.6%·(10 a)-1的速率呈下降趋势。陇中北部、南部以及甘南部分地区为光能和热量资源利用效率的低值区,甘南地区为降水资源利用效率的低值区,兰州市和白银市气候资源综合利用效率较低,分别为0.41和0.47;陇东地区最适宜玉米种植,该地区4种气候资源利用效率均最高,然后依次为甘南和陇中地区;研究区光能、热量、降水以及气候资源综合利用效率的平均倾向率均呈上升趋势,分别为0.1%·(10 a)-1、0.07 kg·hm-2·℃-1·d-1·(10 a)-1、1.17 kg·hm-2·mm-1·(10 a)-1和0.05 ·(10 a)-1,表现出玉米增产的良好潜力。.