宋代江南地区的粮食亩产及其估算方法辨析

A Discussion on the Per Mu Grain Yield in the South of the Yangtze in the Song Dynasty and the Method of Its Estimation

本文指出按每亩地租翻倍而计来估测宋代亩产之法 ,往往低估了当时农业生产所达到的水平。其因有二 ,一是私租本身有分成制、定额制之别 ,而定额制租率较分成制往往低 2 0 % ;又未能区分官租与私租之别 ,而官租在数额上 ,又要低于私租 2 0 %左右 ;二是未能考虑到江南多数地区的耕作制度自宋以来已从一年一熟变为一年两熟制 ,而佃农所交租多半只是一造之数。进而依据文献记载重估了宋代江南地区每亩单产和农业生产所达到的水平。

This paper indicates that the method of estimating the per mu grain yield by doubling the land rent in the Song Dynasty tends to underestimate the agricultural production level at that time.The lack of consideration of the following two points attributes to this:firstly,private rent includes distribution system and quota systerm,with the rent rate of the latter being lower than that of the former by 20%; moreover,there exists the distinction between official rent and private rent,with the former being lower than the latter by 20%;secondly,the cropping system in most of the places in the South of the Yangtze has undergone the change from one crop to two crops a year since the Song Dynasty,but the farmers paid the rent only once a year.On the basis of this analysis and relevant documents,this paper has reestimated the per mu yield in the South of the Yangtze and the agricultural production level of the Song Dynasty.