Rice cultivation's effectiveness in Japan's history
 

Hello,

I'm interested in the methods and effectiveness of rice cultivation
in medieval Japan; mainly during the late Muromachi Period, the
entirety of Azuchi-Momoyama Period and the early Tokugawa Period (in
numbers, roughly between 1530 and 1630).
I'd be keen to know approximately how much workforce was usually
assigned to cultivating, say, a cho of wet rice paddy (one either pre-
or post-Hideyoshi smile), and how much time did it take to collect
that rice?
I've read [1] that there were in China in the 16th century varieties
of rice that matured as quickly as 50 days after the transplanting
(with the rice in a seed bed before transplanting for 4-6 weeks). Did
Japan have rice varieties that were equivalent to this?
Chinese farmers also succeeded in getting already in the 12th
century 10:1 yield/seed ratios for wheat and barley, better than that
for rice, and didn't have to leave any fields to fallow. How did a
Japanese rice-farmer's ability compare to this? Were there any notable
improvements in the method of sowing / harvesting itself in Japan
during this period?
I apologize to those who are offended by the cross-posting of this
message to both sci.agriculture and soc.culture.japan but I thought it
might be of interest to some members of both groups, and that the
increased interaction would prove beneficial to those parties (well,
yes, including me). If you feel the need to flame me about it in
public, please restrict it to the newsgroup you frequent.
Any helpful comments are much appreciated,

-- joeru

[1] "Chinese Economic Performance in the Long Run", by A. Maddison.
OECD Development Centre, Paris. 1998.