AbstractIn Taiwan the rice yield is generally lower in the second crop than in the first crop. This difference is generally attributed to the difference in climatic conditions in these two seasons. In Pingtung area this tendency is more prominent on calcareous soils than on other types of soils. Due to this reason, it has been speculated at one of the reasons for the abovementioned seasonal difference in the rice yield is associated With the nature of soils (1).