北宋中期路域耕地面积的再估算

基于历史文献研究的方法,利用北宋中期垦田数据及宋代人口粮食需求量、粮食亩产量等史料,考察了北宋中期南北方的垦田隐匿特点、北宋户均垦田数的合理范围及西南五路的户均基本垦田需求,并据此对北宋中期路域耕地面积进行了再估算。主要结论：北宋垦田隐匿比例不具有北高南低的区域分异特征;北宋户均垦田数的合理范围为20~100亩;西南五路的户均基本垦田需求数约为20~30亩;北宋中期境内耕地面积约为731.9×10⁶今亩,土地垦殖率为16.9%,其中,北方耕地面积约占29.7%,南方约占70.3%;黄淮海平原、长江中下游平原、两湖平原和成都平原等是北宋耕地的主要分布区,而西南地区垦殖率较低。合理订正北宋中期路域耕地面积,对重建中国过去千年LUCC数据集具有重要意义。

A re-estimation of cropland area at Lu scale in the mid-Northern Song dynasty

Based on "Cropland Taxes", "the Number of Households", "Per Labor Cropland Area", "Per Capita Grain Demand" and "Grain Output Per Mu" data recorded in historical documents, this paper re-estimates cropland area of each Lu (administrative region of the Northern Song dynasty) during the mid-Northern Song dynasty by analyzing some factors of the Northern Song dynasty, including land-use practices and taxation system. The results are shown as follows: (1) Effected by the land-use practices and taxation system, the cropland hidden problem in the Northern Song dynasty is very serious, and each Lu has different characteristics, but it has no obvious difference in the north and south (2.03 of the north and 1.93 of the south). (2) Per household cropland area ranges from 20 to 100 Song-mu (area unit of the Northern Song dynasty, 1 Song-mu=584.0 m²) in the Northern Song dynasty. However, per household cropland area in some Lus of the Southwest is lower, including Zizhou, Lizhou, Kuizhou, Guangnandong and Guangnanxi Lus. The basic cropland area demand of each household in Zizhou, Lizhou and Guangnandong Lus is 20 Song-mu; while that in Kuizhou and Guangnanxi Lus is 30 Song-mu. The re-estimation results of cropland area in Zizhou, Lizhou, Guangnandong, Kuizhou and Guangnanxi Lus are 9.56×10⁶, 7.45×10⁶, 7.63×10⁶, 11.59×10⁶ and 7.15×10⁶ Song-mu, respectively. (3) The cropland area of the whole country in the mid-Northern Song dynasty is about 731.9×10⁶ mu (Chinese area unit, 1 mu = 666.7 m²), accounting for 29.7% of the north and 70.3% of the south. The territory land reclamation rate of the whole country, the north, and the south are 16.9%, 19.0% and 16.1% respectively, and per capita cropland area is 8.4 mu. (4) The cropland is mainly distributed in the North China Plain, the Yangtze River Plain, the Guanzhong Plain, the plains of Hunan and Hubei, and the Sichuan Basin. The land reclamation rate of some Lus is more than 35%, while that of the Southwest China (except the Chengdu Plain) is less than 6%.