1987—2017年青海省东部农业区粮食作物生产潜力及产量差时空变化特征

Grain Crops in Eastern Agricultural Region of Qinghai During 1987-2017:Spatio-temporal Variation Characteristics of Potential Productivity and Yield Gaps

为了研究青海省东部农业区粮食生产潜力及主要限制性气候因子,笔者利用1987—2017年4—9月青海省东部农业区13个气象台站的逐日气象要素和粮食作物实际产量资料,采用逐步订正模型,分析了粮食作物的生产潜力、实际产量及产量差的时空变化特征。结果表明:1987—2017年光合生产潜力呈下降趋势,而光温生产潜力、气候生产潜力以及粮食作物实际产量均呈增加趋势变化;光温生产潜力实现了光合生产潜力的37%,气候生产潜力实现了光温生产潜力的53%,说明产量潜力仍有较大的提升空间,气温和降水是提高生产潜力的限制因素;气候生产潜力与实际产量的产量差平均每10年下降178.6 kg/hm^2,除贵德、循化、同仁产量进一步提升难度较大外,其余大部地区可以通过优化灌溉、合理利用热量资源等途径缩小产量差距。

The paper aims to study the potential productivity and main limiting climatic factors of grain crops in eastern agricultural region of Qinghai. Based on the daily meteorological elements and actual grain yield data of 13 meteorological stations from April to September during 1987-2017 in eastern agricultural region of Qinghai, we analyzed the spatio-temporal variation characteristics of the potential productivity, actual yields and the yield gaps of grain crops by using a successive correction model. The results showed that: the photosynthetic potential productivity(PPP) decreased during 1987-2017 and photo-thermal potential productivity(PTPP), climate potential productivity(CPP) and actual grain yield increased since 1987;the PTPP had achieved 37% of the PPP and the CPP had achieved 53% of the PTPP, indicating that the potential productivity had a great promotion space, and the temperature and precipitation were the limiting climatic factors to improve the potential productivity;the yield gap between the CPP and actual productivity decreased with a rate of 178.6 kg/hm^2 every 10 years, the further improvement of the actual yield was more difficult in Guide, Xunhua and Tongren, but the actual yield gap could be reduced by optimizing fertilization and rationally utilizing heat resources for most other areas.