Microclimatic studies on some methods of irrigation in the rice-field. (4)

Abstract

In the plain district of Kyushu, the climate is almost subtropical in summer season.
For the paddy rice, low field-temperature depending on continuous irrigation with running-water is more favorable than high temperature based on stagnant water.
At the beginning of running-water irrigation, the soil-temperature instantly follows the water-temperature and becomes lower, while it continues lower for a week or so after the stopping of this irrigation, compared with that in the field with stagnant water.
Accordingly, the running-water irrigation should be ended some days before the artificial control of temperature becomes unnecessary.