LATE CHOSON PROPOSALS 363
on a measure of the crop harvested relative to the amount of seed planted on the
most fertile coastal paddy land in those two provinces, not the least fertile land.
For fertile land 1 -2 mal of seed yielded a dozen sam (i.e., 180 mal) of grain, a
yield/seed ratio of 90/1 or 18°/1, a higher estimate than Yi lk made of^6 °/1 for the
early eighteenth century, while in the upland dry fields of Kyonggi and Kangwon
provinces, 1-2 sam (15-30 mal) of seed yielded 5-6 sam (75-90 mal) of crop,
a crop/seed ratio that varied from a low of 2-'YI to a high of 6/T, somewhat lower
than Yi Ik's estimate of TOIl. 21 This yield/seed ratio on dry land was closer to
Braudel's estimate of wheat yields for Europe from the fifteenth through eigh-
teenth centuries, but luckily for the Koreans, rice, grown primarily in the south-
ern three provinces, was the staple crop where yields were much higher.
Another estimate of production was based on the yield per kyol, but unfortu-
nately the area of one kyo! varied from 2.2 to 9 acres depending on the fertility
of the land - a less than ideal measure for a modem statistician. One estimate
of the average production of rice per kw)l in the late Koryo period in the 1380s
was 45 sam, and in 1446 the CMnje sangjongso (Bureau for the Determination
of the Land System) reported that the average yield on I kyol of land was 53.3
sam (799.5 mal), but these two estimates were only for the most fertile land in
the country. Kim Chaejin discounted this high a yield for estimating average
productivity and concluded that the average yield must have been 20 sam/ky/il.n
In fact, in 1445 during the debate over the kongbop tax reform, Ha Yon esti-
mated that the most productive land yielded 50 to 60 siim/ky()l while the least
productive produced only 20 to 30 som/kyol, so that the average yield must have
been 40 sam/kyo!, but this is a numerical average only and did not weight the
calculation by any estimate of the percentage of land in the best and worst cat-
egories. Of the six categories of kY(ll established in 1445, the highest and low-
est two ranks of fertility existed only rarely; most land was graded as third or
fourth grade.^2 ' On this basis, the average yield should have been closer to 25 to
30 than 40 sam/kyo!. Kim Chaejin's estimate of 20 sam/kyo! could easily have
been correct except that the statistical basis for an exact estimate is lacking.
In the early seventeenth century after Hideyoshi's invasion had laid waste the
land, Cho Ik estimated the yield/seed ratio of agricultural land at 18.75 to 20!J
(75'Y40 or 600/)0 mal) for the most fertile land under the most favorable weather
conditions, Iota I leYI for land of medium fertility under average weather con-
ditions, and 5 to 7.5/, for the poorest land during the worst weather conditions -
a serious decline from the yield/seed standards of the mid-fifteenth century!
On the other hand, the estimate of productivity per kyo! was from Iota 50
sam/kya!, while the production from fields of average fertility under average
weather conditions was 20 to 30 s6/1l/kyc'il-figures that were not that different
from the early Choson period. Since the tax rate was 4 mullkyc'51 on the poorest
land, and 6 mal/kya! on average land, the tax rate on average land was from 1.7
to 2.7 percent of the crop on land of poor and medium fertility (6 mal/350 rna!
- 4 ma!1r 50 mal), indicating that the tax rate had dropped considerably from