清代以来华北平原作物熟制演变重建与驱动力分析

Reconstruction of the evolution of cropping pattern in the North China Plain since the Qing Dynasty and driver analysis

历史土地集约利用重建是深入探究气候变化机制和影响的基础。本文从地方志和期刊论文中提取了清代以来华北平原不同地区(点)、不同时段的作物熟制及种植组合信息,据此重建了清代、中华民国(1912—1949年)、20世纪50年代、20世纪60年代、20世纪70年代、20世纪80年代以来6个时段华北平原作物熟制及主要种植组合的时空演变,并探讨了其驱动力。结果表明:(1)清代至20世纪50年代华北平原作物熟制较稳定,以一年一熟和两年三熟为主,一年一熟主要集中在平原北部,两年三熟则多分布在河南和山东省。在灌溉和农业技术的驱动下,20世纪60—70年代华北平原大部分地区作物熟制演进为一年两熟、一年两熟与两年三熟混合,20世纪80年代以来则以一年两熟为主。(2)清代至20世纪50年代华北平原作物种植组合较稳定,一年一熟主要为谷、高粱等作物春种秋收,两年三熟作物组合以春玉米、冬小麦、豆类为主。20世纪60年代以来,一年两熟制作物组成在山东、河南、河北为冬小麦—夏玉米,在淮北为冬小麦—水稻;两年三熟制作物组合中夏作物由豆类发展成玉米/谷类。(3)清代以来,华北平原始终具备发展两年三熟、一年两熟的热量条件。热量变化并不是驱动华北平原清代以来熟制演变的主导因素,1949年中华人民共和国成立以来农业生产条件的改善和生产关系的变革推动了多熟制的快速发展。

The reconstruction of historical land use intensification is the basis for in-depth exploration of climate change mechanisms and impacts.In this study,we first extracted the information of cropping intensity and crop combinations from gazetteers and journal publications for different regions of the North China Plain(NCP)since the Qing Dynasty.Then we reconstructed the spatiotemporal evolution of cropping pattern in the NCP for six periods,including the Qing Dynasty,the late Qing Dynasty to the Republic of China,the early period of the People's Republic of China(1960s,1970s,and 1980s),and discussed the drivers of the change of cropping pattern.We found that:(1)From the Qing Dynasty to the early period of the People's Republic of China,the cropping intensity in the NCP was relatively stable,harvesting once a year or three times in two years.The situation of one harvest a year is mainly concentrated in the northern part of the study area,and the three harvests in two years are mostly distributed in Henan and Shandong provinces.Driven by irrigation and agricultural techniques,the cropping intensity in much of the NCP was two harvests a year,or a mix of two harvests a year and three harvests in two years during the 1960s and 1970s.In the 1980s,the cropping intensity was dominated by two harvests a year.(2)From the Qing Dynasty to the early period of the People's Republic of China,the crop combinations were relatively stable.The pattern of harvesting once a year is that cereals and sorghum are planted in the spring and harvested in the fall.The combination of crops harvested three times in two years is dominated by spring maize,winter wheat and beans.Since the 1960s,the composition of crops harvested twice a year has been winter wheat-summer maize in Shandong,Henan,and Hebei,and winter wheat-rice in the north of the Huaihe River.The summer crop of the crop mix harvested three times in two years developed from beans to maize/cereals.(3)Since the Qing Dynasty,the NCP has always had the thermal conditions for harvesting twice a year or three times in two years.The changes of thermal conditions are not the dominant factor driving the evolution of the cropping intensity in the NCP since the Qing Dynasty.Since the founding of the People's Republic of China,the improvement of agricultural production conditions and the reform of production relations have promoted the rapid development of multiple cropping.